| Installation Guide9.7. Setting the HostnameSetup prompts you to supply a host name for this computer, either as a fully-qualified domain name (FQDN) in the format hostname.domainname or as a short host name in the format hostname. Many networks have a Dynamic Host Configuration Protocol (DHCP) service that automatically supplies connected systems with a domain name. To allow the DHCP service to assign the domain name to this machine, specify the short host name only. You may give your system any name provided that the full hostname is unique. The hostname may include letters, numbers and hyphens. If your Red Hat Enterprise Linux system is connected directly to the Internet, you must pay attention to additional considerations to avoid service interruptions or risk action by your upstream service provider. A full discussion of these issues is beyond the scope of this document. The installation program does not configure modems. Configure these devices after installation with the Network utility. The settings for your modem are specific to your particular Internet Service Provider (ISP). 9.7.1. Edit Network ConnectionsWhen a Red Hat Enterprise Linux 6 installation boots for the first time, it activates any network interfaces that you configured during the installation process. However, the installer does not prompt you to configure network interfaces on some common installation paths, for example, when you install Red Hat Enterprise Linux from a DVD to a local hard drive. When you install Red Hat Enterprise Linux from a local installation source to a local storage device, be sure to configure at least one network interface manually if you require network access when the system boots for the first time. You will need to select the Connect automatically option manually when editing the connection. To change your network configuration after you have completed the installation, use the Network Administration Tool. Type the system-config-network command in a shell prompt to launch the Network Administration Tool. If you are not root, it prompts you for the root password to continue. The Network Administration Tool is now deprecated and will be replaced by NetworkManager during the lifetime of Red Hat Enterprise Linux 6. To configure a network connection manually, click the button Configure Network. The Network Connections dialog appears that allows you to configure wired, wireless, mobile broadband, InfiniBand, VPN, DSL, VLAN, and bonded connections for the system using the NetworkManager tool. A full description of all configurations possible with NetworkManager is beyond the scope of this guide. This section only details the most typical scenario of how to configure wired connections during installation. Configuration of other types of network is broadly similar, although the specific parameters that you must configure are necessarily different. To add a new connection, click Add and select a connection type from the menu. To modify an existing connection, select it in the list and click Edit. In either case, a dialog box appears with a set of tabs that is appropriate to the particular connection type, as described below. To remove a connection, select it in the list and click Delete. When you have finished editing network settings, click Apply to save the new configuration. If you reconfigured a device that was already active during installation, you must restart the device to use the new configuration - refer to Section 9.7.1.6, "Restart a network device". 9.7.1.1. Options common to all types of connectionCertain configuration options are common to all connection types. Specify a name for the connection in the Connection name name field. Select Connect automatically to start the connection automatically when the system boots. When NetworkManager runs on an installed system, the Available to all users option controls whether a network configuration is available system-wide or not. During installation, ensure that Available to all users remains selected for any network interface that you configure. Use the Wired tab to specify or change the media access control (MAC) address for the network adapter, and either set the maximum transmission unit (MTU, in bytes) that can pass through the interface. 9.7.1.3. The 802.1x Security tabUse the 802.1x Security tab to configure 802.1X port-based network access control (PNAC). Select Use 802.1X security for this connection to enable access control, then specify details of your network. The configuration options include: - Authentication
Choose one of the following methods of authentication: TLS for Transport Layer Security Tunneled TLS for Tunneled Transport Layer Security, otherwise known as TTLS, or EAP-TTLS Protected EAP (PEAP) for Protected Extensible Authentication Protocol
- Identity
Provide the identity of this server. - User certificate
Browse to a personal X.509 certificate file encoded with Distinguished Encoding Rules (DER) or Privacy Enhanced Mail (PEM). - CA certificate
Browse to a X.509 certificate authority certificate file encoded with Distinguished Encoding Rules (DER) or Privacy Enhanced Mail (PEM). - Private key
Browse to a private key file encoded with Distinguished Encoding Rules (DER), Privacy Enhanced Mail (PEM), or the Personal Information Exchange Syntax Standard (PKCS#12). - Private key password
The password for the private key specified in the Private key field. Select Show password to make the password visible as you type it.
9.7.1.4. The IPv4 Settings tabUse the IPv4 Settings tab tab to configure the IPv4 parameters for the previously selected network connection. Use the Method drop-down menu to specify which settings the system should attempt to obtain from a Dynamic Host Configuration Protocol (DHCP) service running on the network. Choose from the following options: - Automatic (DHCP)
IPv4 parameters are configured by the DHCP service on the network. - Automatic (DHCP) addresses only
The IPv4 address, netmask, and gateway address are configured by the DHCP service on the network, but DNS servers and search domains must be configured manually. - Manual
IPv4 parameters are configured manually for a static configuration. - Link-Local Only
A link-local address in the 169.254/16 range is assigned to the interface. - Shared to other computers
The system is configured to provide network access to other computers. The interface is assigned an address in the 10.42.x.1/24 range, a DHCP server and DNS server are started, and the interface is connected to the default network connection on the system with network address translation (NAT). - Disabled
IPv4 is disabled for this connection.
If you selected a method that requires you to supply manual parameters, enter details of the IP address for this interface, the netmask, and the gateway in the Addresses field. Use the Add and Delete buttons to add or remove addresses. Enter a comma-separated list of DNS servers in the DNS servers field, and a comma-separated list of domains in the Search domains field for any domains that you want to include in name server lookups. Optionally, enter a name for this network connection in the DHCP client ID field. This name must be unique on the subnet. When you assign a meaningful DHCP client ID to a connection, it is easy to identify this connection when troubleshooting network problems. Deselect the Require IPv4 addressing for this connection to complete check box to allow the system to make this connection on an IPv6-enabled network if IPv4 configuration fails but IPv6 configuration succeeds. 9.7.1.4.1. Editing IPv4 routesRed Hat Enterprise Linux configures a number of routes automatically based on the IP addresses of a device. To edit additional routes, click the Routes button. The Editing IPv4 routes dialog appears. Click Add to add the IP address, netmask, gateway address, and metric for a new static route. Select Ignore automatically obtained routes to make the interface use only the routes specified for it here. Select Use this connection only for resources on its network to restrict connections only to the local network. 9.7.1.5. The IPv6 Settings tabUse the IPv6 Settings tab tab to configure the IPv6 parameters for the previously selected network connection. Use the Method drop-down menu to specify which settings the system should attempt to obtain from a Dynamic Host Configuration Protocol (DHCP) service running on the network. Choose from the following options: - Ignore
IPv6 is ignored for this connection. - Automatic
NetworkManager uses router advertisement (RA) to create an automatic, stateless configuration. - Automatic, addresses only
NetworkManager uses RA to create an automatic, stateless configuration, but DNS servers and search domains are ignored and must be configured manually. - Automatic, DHCP only
NetworkManager does not use RA, but requests information from DHCPv6 directly to create a stateful configuration. - Manual
IPv6 parameters are configured manually for a static configuration. - Link-Local Only
A link-local address with the fe80::/10 prefix is assigned to the interface.
If you selected a method that requires you to supply manual parameters, enter details of the IP address for this interface, the netmask, and the gateway in the Addresses field. Use the Add and Delete buttons to add or remove addresses. Enter a comma-separated list of DNS servers in the DNS servers field, and a comma-separated list of domains in the Search domains field for any domains that you want to include in name server lookups. Optionally, enter a name for this network connection in the DHCP client ID field. This name must be unique on the subnet. When you assign a meaningful DHCP client ID to a connection, it is easy to identify this connection when troubleshooting network problems. Deselect the Require IPv6 addressing for this connection to complete check box to allow the system to make this connection on an IPv4-enabled network if IPv6 configuration fails but IPv4 configuration succeeds. 9.7.1.5.1. Editing IPv6 routesRed Hat Enterprise Linux configures a number of routes automatically based on the IP addresses of a device. To edit additional routes, click the Routes button. The Editing IPv6 routes dialog appears. Click Add to add the IP address, netmask, gateway address, and metric for a new static route. Select Use this connection only for resources on its network to restrict connections only to the local network. 9.7.1.6. Restart a network deviceIf you reconfigured a network that was already in use during installation, you must disconnect and reconnect the device in anaconda for the changes to take effect. Anaconda uses interface configuration (ifcfg) files to communicate with NetworkManager. A device becomes disconnected when its ifcfg file is removed, and becomes reconnected when its ifcfg file is restored, as long as ONBOOT=yes is set. Refer to the Red Hat Enterprise Linux 6 Deployment Guide available from https://access.redhat.com/knowledge/docs/ for more information about interface configuration files. Press Ctrl+Alt+F2 to switch to virtual terminal tty2. Move the interface configuration file to a temporary location: mv /etc/sysconfig/network-scripts/ifcfg-device_name /tmp where device_name is the device that you just reconfigured. For example, ifcfg-eth0 is the ifcfg file for eth0. The device is now disconnected in anaconda. Open the interface configuration file in the vi editor: vi /tmp/ifcfg-device_name Verify that the interface configuration file contains the line ONBOOT=yes. If the file does not already contain the line, add it now and save the file. Exit the vi editor. Move the interface configuration file back to the /etc/sysconfig/network-scripts/ directory: mv /tmp/ifcfg-device_name /etc/sysconfig/network-scripts/ The device is now reconnected in anaconda. Press Ctrl+Alt+F6 to return to anaconda.
9.8. Time Zone ConfigurationSet your time zone by selecting the city closest to your computer's physical location. Click on the map to zoom in to a particular geographical region of the world. Specify a time zone even if you plan to use NTP (Network Time Protocol) to maintain the accuracy of the system clock. From here there are two ways for you to select your time zone: Using your mouse, click on the interactive map to select a specific city (represented by a yellow dot). A red X appears indicating your selection. You can also scroll through the list at the bottom of the screen to select your time zone. Using your mouse, click on a location to highlight your selection.
If Red Hat Enterprise Linux is the only operating system on your computer, select System clock uses UTC. The system clock is a piece of hardware on your computer system. Red Hat Enterprise Linux uses the timezone setting to determine the offset between the local time and UTC on the system clock. This behavior is standard for systems that use UNIX, Linux, and similar operating systems. Click Next to proceed. Do not enable the System clock uses UTC option if your machine also runs Microsoft Windows. Microsoft operating systems change the BIOS clock to match local time rather than UTC. This may cause unexpected behavior under Red Hat Enterprise Linux. To change your time zone configuration after you have completed the installation, use the Time and Date Properties Tool. Type the system-config-date command in a shell prompt to launch the Time and Date Properties Tool. If you are not root, it prompts you for the root password to continue. To run the Time and Date Properties Tool as a text-based application, use the command timeconfig. 9.9. Set the Root PasswordSetting up a root account and password is one of the most important steps during your installation. The root account is used to install packages, upgrade RPMs, and perform most system maintenance. Logging in as root gives you complete control over your system. The root user (also known as the superuser) has complete access to the entire system; for this reason, logging in as the root user is best done only to perform system maintenance or administration. Use the root account only for system administration. Create a non-root account for your general use and use the su command to change to root only when you need to perform tasks that require superuser authorization. These basic rules minimize the chances of a typo or an incorrect command doing damage to your system. To become root, type su - at the shell prompt in a terminal window and then press Enter. Then, enter the root password and press Enter. The installation program prompts you to set a root password for your system. . You cannot proceed to the next stage of the installation process without entering a root password.The root password must be at least six characters long; the password you type is not echoed to the screen. You must enter the password twice; if the two passwords do not match, the installation program asks you to enter them again. You should make the root password something you can remember, but not something that is easy for someone else to guess. Your name, your phone number, qwerty, password, root, 123456, and anteater are all examples of bad passwords. Good passwords mix numerals with upper and lower case letters and do not contain dictionary words: Aard387vark or 420BMttNT, for example. Remember that the password is case-sensitive. If you write down your password, keep it in a secure place. However, it is recommended that you do not write down this or any password you create. Do not use one of the example passwords offered in this manual. Using one of these passwords could be considered a security risk. To change your root password after you have completed the installation, use the Root Password Tool. Type the system-config-users command in a shell prompt to launch the User Manager, a powerful user management and configuration tool. If you are not root, it prompts you for the root password to continue. Enter the root password into the Root Password field. Red Hat Enterprise Linux displays the characters as asterisks for security. Type the same password into the Confirm field to ensure it is set correctly. After you set the root password, select Next to proceed. 9.10. Assign Storage Devices If you selected more than one storage device on the storage devices selection screen (refer to Section 9.6, "Storage Devices"), anaconda asks you to select which of these devices should be available for installation of the operating system, and which should only be attached to the file system for data storage. If you selected only one storage device, anaconda does not present you with this screen. During installation, the devices that you identify here as being for data storage only are mounted as part of the file system, but are not partitioned or formatted. The screen is split into two panes. The left pane contains a list of devices to be used for data storage only. The right pane contains a list of devices that are to be available for installation of the operating system. Each list contains information about the devices to help you to identify them. A small drop-down menu marked with an icon is located to the right of the column headings. This menu allows you to select the types of data presented on each device. Reducing or expanding the amount of information presented might help you to identify particular devices. Move a device from one list to the other by clicking on the device, then clicking either the button labeled with a left-pointing arrow to move it to the list of data storage devices or the button labeled with a right-pointing arrow to move it to the list of devices available for installation of the operating system. The list of devices available as installation targets also includes a radio button beside each device. Use this radio button to specify the device that you want to use as the boot device for the system. If any storage device contains a boot loader that will chain load the Red Hat Enterprise Linux boot loader, include that storage device among the Install Target Devices. Storage devices that you identify as Install Target Devices remain visible to anaconda during boot loader configuration. Storage devices that you identify as Install Target Devices on this screen are not automatically erased by the installation process unless you selected the Use All Space option on the partitioning screen (refer to Section 9.13, "Disk Partitioning Setup"). When you have finished identifying devices to be used for installation, click Next to continue. 9.11. Initializing the Hard DiskIf no readable partition tables are found on existing hard disks, the installation program asks to initialize the hard disk. This operation makes any existing data on the hard disk unreadable. If your system has a brand new hard disk with no operating system installed, or you have removed all partitions on the hard disk, click Re-initialize drive. The installation program presents you with a separate dialog for each disk on which it cannot read a valid partition table. Click the Ignore all button or Re-initialize all button to apply the same answer to all devices. Certain RAID systems or other nonstandard configurations may be unreadable to the installation program and the prompt to initialize the hard disk may appear. The installation program responds to the physical disk structures it is able to detect. To enable automatic initializing of hard disks for which it turns out to be necessary, use the kickstart command clearpart --initlabel (refer to Chapter 32, Kickstart Installations) If you have a nonstandard disk configuration that can be detached during installation and detected and configured afterward, power off the system, detach it, and restart the installation. 9.12. Upgrading an Existing System Red Hat does not support in-place upgrades between any major versions of Red Hat Enterprise Linux. A major version is denoted by a whole number version change. For example, Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6 are both major versions of Red Hat Enterprise Linux. In-place upgrades across major releases do not preserve all system settings, services or custom configurations. Consequently, Red Hat strongly recommends fresh installations when upgrading from one major version to another. The installation system automatically detects any existing installation of Red Hat Enterprise Linux. The upgrade process updates the existing system software with new versions, but does not remove any data from users' home directories. The existing partition structure on your hard drives does not change. Your system configuration changes only if a package upgrade demands it. Most package upgrades do not change system configuration, but rather install an additional configuration file for you to examine later. Note that the installation medium that you are using might not contain all the software packages that you need to upgrade your computer. 9.12.1. The Upgrade Dialog If your system contains a Red Hat Enterprise Linux installation, a dialog appears asking whether you want to upgrade that installation. To perform an upgrade of an existing system, choose the appropriate installation from the drop-down list and select Next. Software you have installed manually on your existing Red Hat Enterprise Linux system may behave differently after an upgrade. You may need to manually reinstall or recompile this software after an upgrade to ensure it performs correctly on the updated system. 9.12.2. Upgrading Using the Installer In general, Red Hat recommends that you keep user data on a separate /home partition and perform a fresh installation. For more information on partitions and how to set them up, refer to Section 9.13, "Disk Partitioning Setup". If you choose to upgrade your system using the installation program, any software not provided by Red Hat Enterprise Linux that conflicts with Red Hat Enterprise Linux software is overwritten. Before you begin an upgrade this way, make a list of your system's current packages for later reference: rpm -qa --qf '%{NAME} %{VERSION}-%{RELEASE} %{ARCH}\n' > ~/old-pkglist.txt
After installation, consult this list to discover which packages you may need to rebuild or retrieve from sources other than Red Hat. Next, make a backup of any system configuration data: su -c 'tar czf /tmp/etc-`date +%F`.tar.gz /etc' su -c 'mv /tmp/etc-*.tar.gz /home'
Make a complete backup of any important data before performing an upgrade. Important data may include the contents of your entire /home directory as well as content from services such as an Apache, FTP, or SQL server, or a source code management system. Although upgrades are not destructive, if you perform one improperly there is a small possibility of data loss. Note that the above examples store backup materials in a /home directory. If your /home directory is not a separate partition, you should not follow these examples verbatim! Store your backups on another device such as CD or DVD discs or an external hard disk. 9.12.3. Upgrading Boot Loader Configuration Your completed Red Hat Enterprise Linux installation must be registered in the boot loader to boot properly. A boot loader is software on your machine that locates and starts the operating system. Refer to Appendix E, The GRUB Boot Loader for more information about boot loaders. If the existing boot loader was installed by a Linux distribution, the installation system can modify it to load the new Red Hat Enterprise Linux system. To update the existing Linux boot loader, select Update boot loader configuration. This is the default behavior when you upgrade an existing Red Hat Enterprise Linux installation. GRUB is the standard boot loader for Red Hat Enterprise Linux on 32-bit and 64-bit x86 architectures. If your machine uses another boot loader, such as BootMagic, System Commander, or the loader installed by Microsoft Windows, then the Red Hat Enterprise Linux installation system cannot update it. In this case, select Skip boot loader updating. When the installation process completes, refer to the documentation for your product for assistance. Install a new boot loader as part of an upgrade process only if you are certain you want to replace the existing boot loader. If you install a new boot loader, you may not be able to boot other operating systems on the same machine until you have configured the new boot loader. Select Create new boot loader configuration to remove the existing boot loader and install GRUB. 9.13. Disk Partitioning SetupIt is always a good idea to back up any data that you have on your systems. For example, if you are upgrading or creating a dual-boot system, you should back up any data you wish to keep on your storage devices. Mistakes do happen and can result in the loss of all your data. If you install Red Hat Enterprise Linux in text mode, you can only use the default partitioning schemes described in this section. You cannot add or remove partitions or file systems beyond those that the installer automatically adds or removes. If you require a customized layout at installation time, you should perform a graphical installation over a VNC connection or a kickstart installation. Furthermore, advanced options such as LVM, encrypted filesystems, and resizable filesystems are available only in graphical mode and kickstart. If you have a RAID card, be aware that some BIOSes do not support booting from the RAID card. In cases such as these, the /boot/ partition must be created on a partition outside of the RAID array, such as on a separate hard drive. An internal hard drive is necessary to use for partition creation with problematic RAID cards. A /boot/ partition is also necessary for software RAID setups. If you have chosen to automatically partition your system, you should select Review and manually edit your /boot/ partition. Partitioning allows you to divide your hard drive into isolated sections, where each section behaves as its own hard drive. Partitioning is particularly useful if you run multiple operating systems. If you are not sure how you want your system to be partitioned, read Appendix A, An Introduction to Disk Partitions for more information. On this screen you can choose to create the default partition layout in one of four different ways, or choose to partition storage devices manually to create a custom layout. The first four options allow you to perform an automated installation without having to partition your storage devices yourself. If you do not feel comfortable with partitioning your system, choose one of these options and let the installation program partition the storage devices for you. Depending on the option that you choose, you can still control what data (if any) is removed from the system. Your options are: - Use All Space
Select this option to remove all partitions on your hard drives (this includes partitions created by other operating systems such as Windows VFAT or NTFS partitions). If you select this option, all data on the selected hard drives is removed by the installation program. Do not select this option if you have information that you want to keep on the hard drives where you are installing Red Hat Enterprise Linux. In particular, do not select this option when you configure a system to chain load the Red Hat Enterprise Linux boot loader from another boot loader. - Replace Existing Linux System(s)
Select this option to remove only partitions created by a previous Linux installation. This does not remove other partitions you may have on your hard drives (such as VFAT or FAT32 partitions). - Shrink Current System
Select this option to resize your current data and partitions manually and install a default Red Hat Enterprise Linux layout in the space that is freed. If you shrink partitions on which other operating systems are installed, you might not be able to use those operating systems. Although this partitioning option does not destroy data, operating systems typically require some free space in their partitions. Before you resize a partition that holds an operating system that you might want to use again, find out how much space you need to leave free. - Use Free Space
Select this option to retain your current data and partitions and install Red Hat Enterprise Linux in the unused space available on the storage drives. Ensure that there is sufficient space available on the storage drives before you select this option - refer to Section 3.5, "Do You Have Enough Disk Space?". If your 64-bit x86 system uses UEFI instead of BIOS, you will need to manually create a /boot partition. This partition must have an ext3 file system. If you choose to partition automatically, your system will not boot. - Create Custom Layout
Choose your preferred partitioning method by clicking the radio button to the left of its description in the dialog box. Select Encrypt system to encrypt all partitions except the /boot partition. Refer to Appendix C, Disk Encryption for information on encryption. To review and make any necessary changes to the partitions created by automatic partitioning, select the Review option. After selecting Review and clicking Next to move forward, the partitions created for you by anaconda appear. You can make modifications to these partitions if they do not meet your needs. To configure the Red Hat Enterprise Linux boot loader to chain load from a different boot loader, you must specify the boot drive manually. If you chose any of the automatic partitioning options, you must now select the Review and modify partitioning layout option before you click Next or you cannot specify the correct boot drive. When you install Red Hat Enterprise Linux 6 on a system with multipath and non-multipath storage devices, the automatic partitioning layout in the installer might create volume groups that contain a mix of multipath and non-multipath devices. This defeats the purpose of multipath storage. We advise that you select only multipath or only non-multipath devices on the disk selection screen that appears after selecting automatic partitioning. Alternatively, select custom partitioning. Click Next once you have made your selections to proceed. If you selected the Encrypt System option, the installer prompts you for a passphrase with which to encrypt the partitions on the system. Choose a passphrase and type it into each of the two fields in the dialog box. You must provide this passphrase every time that the system boots. If you lose this passphrase, any encrypted partitions and the data on them will become completely inaccessible. There is no way to recover a lost passphrase. 9.15. Creating a Custom Layout or Modifying the Default Layout If you chose one of the automatic partitioning options and selected Review, you can either accept the current partition settings (click Next), or modify the setup manually in the partitioning screen. If you chose to create a custom layout, you must tell the installation program where to install Red Hat Enterprise Linux. This is done by defining mount points for one or more disk partitions in which Red Hat Enterprise Linux is installed. You may also need to create and/or delete partitions at this time. If your 64-bit x86 system uses UEFI instead of BIOS, you will need to manually create a /boot partition. This partition must have an ext3 file system. If you choose to partition automatically, your system will not boot. Anaconda can handle the partitioning requirements for a typical installation. The partitioning screen contains two panes. The top pane contains a graphical representation of the hard drive, logical volume, or RAID device selected in the lower pane. Above the graphical representation of the device, you can review the name of the drive (such as /dev/sda or LogVol00), its size (in MB), and its model as detected by the installation program. Using your mouse, click once to highlight a particular field in the graphical display. Double-click to edit an existing partition or to create a partition out of existing free space. The lower pane contains a list of all drives, logical volumes, and RAID devices to be used during installation, as specified earlier in the installation process - refer to Section 9.10, " Assign Storage Devices "Devices are grouped by type. Click on the small triangles to the left of each device type to view or hide devices of that type. Anaconda displays several details for each device listed: - Device
the name of the device, logical volume, or partition - Size (MB)
the size of the device, logical volume, or partition (in MB) - Mount Point/RAID/Volume
the mount point (location within a file system) on which a partition is to be mounted, or the name of the RAID or logical volume group of which it is a part - Type
the type of partition. If the partition is a standard partition, this field displays the type of file system on the partition (for example, ext4). Otherwise, it indicates that the partition is a physical volume (LVM), or part of a software RAID - Format
A check mark in this column indicates that the partition will be formatted during installation.
Beneath the lower pane are four buttons: Create, Edit, Delete, and Reset. Select a device or partition by clicking on it in either the graphical representation in the upper pane of in the list in the lower pane, then click one of the four buttons to carry out the following actions: - Create
create a new partition, logical volume, or software RAID - Edit
change an existing partition, logical volume, or software RAID. Note that you can only shrink partitions with the Resize button, not enlarge partitions. - Delete
remove a partition, logical volume, or software RAID - Reset
undo all changes made in this screen
The Create Storage dialog allows you to create new storage partitions, logical volumes, and software RAIDs. Anaconda presents options as available or unavailable depending on the storage already present on the system or configured to transfer to the system. Options are grouped under Create Partition, Create Software RAID and Create LVM as follows: Create Software RAID RAID Partition - create a partition in unallocated space to form part of a software RAID device. To form a software RAID device, two or more RAID partitions must be available on the system. RAID Device - combine two or more RAID partitions into a software RAID device. When you choose this option, you can specify the type of RAID device to create (the RAID level). This option is only available when two or more RAID partitions are available on the system.
Create LVM Logical Volume LVM Physical Volume - create a physical volume in unallocated space. LVM Volume Group - create a volume group from one or more physical volumes. This option is only available when at least one physical volume is available on the system. LVM Logical Volume - create a logical volume on a volume group. This option is only available when at least one volume group is available on the system.
9.15.2. Adding PartitionsMount Point: Enter the partition's mount point. For example, if this partition should be the root partition, enter /; enter /boot for the /boot partition, and so on. You can also use the pull-down menu to choose the correct mount point for your partition. For a swap partition the mount point should not be set - setting the filesystem type to swap is sufficient. File System Type: Using the pull-down menu, select the appropriate file system type for this partition. For more information on file system types, refer to Section 9.15.2.1, "File System Types". Allowable Drives: This field contains a list of the hard disks installed on your system. If a hard disk's box is highlighted, then a desired partition can be created on that hard disk. If the box is not checked, then the partition will never be created on that hard disk. By using different checkbox settings, you can have anaconda place partitions where you need them, or let anaconda decide where partitions should go. Size (MB): Enter the size (in megabytes) of the partition. Note, this field starts with 200 MB; unless changed, only a 200 MB partition will be created. Additional Size Options: Choose whether to keep this partition at a fixed size, to allow it to "grow" (fill up the available hard drive space) to a certain point, or to allow it to grow to fill any remaining hard drive space available. If you choose Fill all space up to (MB), you must give size constraints in the field to the right of this option. This allows you to keep a certain amount of space free on your hard drive for future use. Encrypt: Choose whether to encrypt the partition so that the data stored on it cannot be accessed without a passphrase, even if the storage device is connected to another system. Refer to Appendix C, Disk Encryption for information on encryption of storage devices. If you select this option, the installer prompts you to provide a passphrase before it writes the partition to the disk. OK: Select OK once you are satisfied with the settings and wish to create the partition. Cancel: Select Cancel if you do not want to create the partition.
9.15.2.1. File System TypesRed Hat Enterprise Linux allows you to create different partition types and file systems. The following is a brief description of the different partition types and file systems available, and how they can be used. Partition types standard partition - A standard partition can contain a file system or swap space, or it can provide a container for software RAID or an LVM physical volume. swap - Swap partitions are used to support virtual memory. In other words, data is written to a swap partition when there is not enough RAM to store the data your system is processing. Refer to the Red Hat Enterprise Linux Deployment Guide for additional information. software RAID - Creating two or more software RAID partitions allows you to create a RAID device. For more information regarding RAID, refer to the chapter RAID (Redundant Array of Independent Disks) in the Red Hat Enterprise Linux Deployment Guide. physical volume (LVM) - Creating one or more physical volume (LVM) partitions allows you to create an LVM logical volume. LVM can improve performance when using physical disks. For more information regarding LVM, refer to the Red Hat Enterprise Linux Deployment Guide.
File systems ext4 - The ext4 file system is based on the ext3 file system and features a number of improvements. These include support for larger file systems and larger files, faster and more efficient allocation of disk space, no limit on the number of subdirectories within a directory, faster file system checking, and more robust journaling. A maximum file system size of 16TB is supported for ext4. The ext4 file system is selected by default and is highly recommended. ext3 - The ext3 file system is based on the ext2 file system and has one main advantage - journaling. Using a journaling file system reduces time spent recovering a file system after a crash as there is no need to fsck the file system. A maximum file system size of 16TB is supported for ext3. ext2 - An ext2 file system supports standard Unix file types (regular files, directories, symbolic links, etc). It provides the ability to assign long file names, up to 255 characters. xfs - XFS is a highly scalable, high-performance file system that supports filesystems up to 16 exabytes (approximately 16 million terabytes), files up to 8 exabytes (approximately 8 million terabytes) and directory structures containing tens of millions of entries. XFS supports metadata journaling, which facilitates quicker crash recovery. The XFS file system can also be defragmented and resized while mounted and active. vfat - The VFAT file system is a Linux file system that is compatible with Microsoft Windows long filenames on the FAT file system. Btrfs - Btrfs is under development as a file system capable of addressing and managing more files, larger files, and larger volumes than the ext2, ext3, and ext4 file systems. Btrfs is designed to make the file system tolerant of errors, and to facilitate the detection and repair of errors when they occur. It uses checksums to ensure the validity of data and metadata, and maintains snapshots of the file system that can be used for backup or repair. Because Btrfs is still experimental and under development, the installation program does not offer it by default. If you want to create a Btrfs partition on a drive, you must commence the installation process with the boot option btrfs. Refer to Chapter 28, Boot Options for instructions. Red Hat Enterprise Linux 6 includes Btrfs as a technology preview to allow you to experiment with this file system. You should not choose Btrfs for partitions that will contain valuable data or that are essential for the operation of important systems.
9.15.3. Create Software RAID Redundant arrays of independent disks (RAIDs) are constructed from multiple storage devices that are arranged to provide increased performance and - in some configurations - greater fault tolerance. Refer to the Red Hat Enterprise Linux Deployment Guide for a description of different kinds of RAIDs. To make a RAID device, you must first create software RAID partitions. Once you have created two or more software RAID partitions, select RAID to join the software RAID partitions into a RAID device. - RAID Partition
Choose this option to configure a partition for software RAID. This option is the only choice available if your disk contains no software RAID partitions. This is the same dialog that appears when you add a standard partition - refer to Section 9.15.2, "Adding Partitions" for a description of the available options. Note, however, that File System Type must be set to software RAID
- RAID Device
Choose this option to construct a RAID device from two or more existing software RAID partitions. This option is available if two or more software RAID partitions have been configured.
Select the file system type as for a standard partition. Anaconda automatically suggests a name for the RAID device, but you can manually select names from md0 to md15. Click the checkboxes beside individual storage devices to include or remove them from this RAID. The RAID Level corresponds to a particular type of RAID. Choose from the following options: RAID 0 - distributes data across multiple storage devices. Level 0 RAIDs offer increased performance over standard partitions, and can be used to pool the storage of multiple devices into one large virtual device. Note that Level 0 RAIDS offer no redundancy and that the failure of one device in the array destroys the entire array. RAID 0 requires at least two RAID partitions. RAID 1 - mirrors the data on one storage device onto one or more other storage devices. Additional devices in the array provide increasing levels of redundancy. RAID 1 requires at least two RAID partitions. RAID 4 - distributes data across multiple storage devices, but uses one device in the array to store parity information that safeguards the array in case any device within the array fails. Because all parity information is stored on the one device, access to this device creates a bottleneck in the performance of the array. RAID 4 requires at least three RAID partitions. RAID 5 - distributes data and parity information across multiple storage devices. Level 5 RAIDs therefore offer the performance advantages of distributing data across multiple devices, but do not share the performance bottleneck of level 4 RAIDs because the parity information is also distributed through the array. RAID 5 requires at least three RAID partitions. RAID 6 - level 6 RAIDs are similar to level 5 RAIDs, but instead of storing only one set of parity data, they store two sets. RAID 6 requires at least four RAID partitions. RAID 10 - level 10 RAIDs are nested RAIDs or hybrid RAIDs. Level 10 RAIDs are constructed by distributing data over mirrored sets of storage devices. For example, a level 10 RAID constructed from four RAID partitions consists of two pairs of partitions in which one partition mirrors the other. Data is then distributed across both pairs of storage devices, as in a level 0 RAID. RAID 10 requires at least four RAID partitions.
9.15.4. Create LVM Logical Volume LVM initial set up is not available during text-mode installation. If you need to create an LVM configuration from scratch, press Alt+F2 to use a different virtual console, and run the lvm command. To return to the text-mode installation, press Alt+F1. Logical Volume Management (LVM) presents a simple logical view of underlying physical storage space, such as a hard drives or LUNs. Partitions on physical storage are represented as physical volumes that can be grouped together into volume groups. Each volume group can be divided into multiple logical volumes, each of which is analogous to a standard disk partition. Therefore, LVM logical volumes function as partitions that can span multiple physical disks. To read more about LVM, refer to the Red Hat Enterprise Linux Deployment Guide. Note, LVM is only available in the graphical installation program. - LVM Physical Volume
Choose this option to configure a partition or device as an LVM physical volume. This option is the only choice available if your storage does not already contain LVM Volume Groups. This is the same dialog that appears when you add a standard partition - refer to Section 9.15.2, "Adding Partitions" for a description of the available options. Note, however, that File System Type must be set to physical volume (LVM)
- Make LVM Volume Group
Choose this option to create LVM volume groups from the available LVM physical volumes, or to add existing logical volumes to a volume group.
To assign one or more physical volumes to a volume group, first name the volume group. Then select the physical volumes to be used in the volume group. Finally, configure logical volumes on any volume groups using the Add, Edit and Delete options. You may not remove a physical volume from a volume group if doing so would leave insufficient space for that group's logical volumes. Take for example a volume group made up of two 5 GB LVM physical volume partitions, which contains an 8 GB logical volume. The installer would not allow you to remove either of the component physical volumes, since that would leave only 5 GB in the group for an 8 GB logical volume. If you reduce the total size of any logical volumes appropriately, you may then remove a physical volume from the volume group. In the example, reducing the size of the logical volume to 4 GB would allow you to remove one of the 5 GB physical volumes. - Make Logical Volume
Choose this option to create an LVM logical volume. Select a mount point, file system type, and size (in MB) just as if it were a standard disk partition. You can also choose a name for the logical volume and specify the volume group to which it will belong.
9.15.5. Recommended Partitioning Scheme9.15.5.1. x86, AMD64, and Intel 64 systemsWe recommend that you create the following partitions for x86, AMD64, and Intel 64 systems: A swap partition A /boot partition A / partition A home partition
In years past, the recommended amount of swap space increased linearly with the amount of RAM in the system. Modern systems often include hundreds of gigabytes of RAM, however. As a consequence, recommended swap space is considered a function of system memory workload, not system memory. The following table provides the recommended size of a swap partition depending on the amount of RAM in your system and whether you want sufficient memory for your system to hibernate. The recommended swap partition size is established automatically during installation. To allow for hibernation, however, you will need to edit the swap space in the custom partitioning stage. Table 9.2. Recommended System Swap Space | Amount of RAM in the system | Recommended swap space | Recommended swap space if allowing for hibernation |
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| ⩽ 2GB | 2 times the amount of RAM | 3 times the amount of RAM | | > 2GB - 8GB | Equal to the amount of RAM | 2 times the amount of RAM | | > 8GB - 64GB | 0.5 times the amount of RAM | 1.5 times the amount of RAM | | > 64GB | 4GB of swap space | No extra space needed |
At the border between each range listed above (for example, a system with 2GB, 8GB, or 64GB of system RAM), discretion can be exercised with regard to chosen swap space and hibernation support. If your system resources allow for it, increasing the swap space may lead to better performance. Note that distributing swap space over multiple storage devices - particularly on systems with fast drives, controllers and interfaces - also improves swap space performance. Swap space size recommendations issued for Red Hat Enterprise Linux 6.0, 6.1, and 6.2 differed from the current recommendations, which were first issued with the release of Red Hat Enterprise Linux 6.3 in June 2012 and did not account for hibernation space. Automatic installations of these earlier versions of Red Hat Enterprise Linux 6 still generate a swap space in line with these superseded recommendations. However, manually selecting a swap space size in line with the newer recommendations issued for Red Hat Enterprise Linux 6.3 is advisable for optimal performance. The GRUB bootloader in Red Hat Enterprise Linux 6 supports only the ext2, ext3, and ext4 (recommended) file systems. You cannot use any other file system for /boot, such as Btrfs, XFS, or VFAT. If your hard drive is more than 1024 cylinders (and your system was manufactured more than two years ago), you may need to create a /boot/ partition if you want the / (root) partition to use all of the remaining space on your hard drive. If you have a RAID card, be aware that some BIOSes do not support booting from the RAID card. In cases such as these, the /boot/ partition must be created on a partition outside of the RAID array, such as on a separate hard drive. A 3.0 GB partition allows you to install a minimal installation, while a 5.0 GB root partition lets you perform a full installation, choosing all package groups. The / (or root) partition is the top of the directory structure. The /root directory (sometimes pronounced "slash-root") is the home directory of the user account for system administration.
The following table summarizes minimum partition sizes for the partitions containing the listed directories. You do not have to make a separate partition for each of these directories. For instance, if the partition containing /foo must be at least 500 MB, and you do not make a separate /foo partition, then the / (root) partition must be at least 500 MB. Table 9.3. Minimum partition sizes | Directory | Minimum size |
|---|
/ | 250 MB | /usr | 250 MB, but avoid placing this on a separate partition | /tmp | 50 MB | /var | 384 MB | /home | 100 MB | /boot | 250 MB |
Only assign storage capacity to those partitions you require immediately. You may allocate free space at any time, to meet needs as they occur. To learn about a more flexible method for storage management, refer to Appendix D, Understanding LVM. If you are not sure how best to configure the partitions for your computer, accept the default partition layout. 9.15.5.1.1. Advice on PartitionsOptimal partition setup depends on the usage for the Linux system in question. The following tips may help you decide how to allocate your disk space. Consider encrypting any partitions that might contain sensitive data. Encryption prevents unauthorized people from accessing the data on the partitions, even if they have access to the physical storage device. In most cases, you should at least encrypt the /home partition. Each kernel installed on your system requires approximately 10 MB on the /boot partition. Unless you plan to install a great many kernels, the default partition size of 250 MB for /boot should suffice. The GRUB bootloader in Red Hat Enterprise Linux 6 supports only the ext2, ext3, and ext4 (recommended) file systems. You cannot use any other file system for /boot, such as Btrfs, XFS, or VFAT. The /var directory holds content for a number of applications, including the Apache web server. It also is used to store downloaded update packages on a temporary basis. Ensure that the partition containing the /var directory has enough space to download pending updates and hold your other content. The PackageKit update software downloads updated packages to /var/cache/yum/ by default. If you partition the system manually, and create a separate /var/ partition, be sure to create the partition large enough (3.0 GB or more) to download package updates. The /usr directory holds the majority of software content on a Red Hat Enterprise Linux system. For an installation of the default set of software, allocate at least 4 GB of space. If you are a software developer or plan to use your Red Hat Enterprise Linux system to learn software development skills, you may want to at least double this allocation. If /usr is partitioned separately from the rest of the root volume, the boot process becomes much more complex because /usr contains boot-critical components. In some situations, such as when installing on an iSCSI drive, the system will not boot. Consider leaving a portion of the space in an LVM volume group unallocated. This unallocated space gives you flexibility if your space requirements change but you do not wish to remove data from other partitions to reallocate storage. If you separate subdirectories into partitions, you can retain content in those subdirectories if you decide to install a new version of Red Hat Enterprise Linux over your current system. For instance, if you intend to run a MySQL database in /var/lib/mysql, make a separate partition for that directory in case you need to reinstall later.
The following table is a possible partition setup for a system with a single, new 80 GB hard disk and 1 GB of RAM. Note that approximately 10 GB of the volume group is unallocated to allow for future growth. This setup is not optimal for all use cases. Example 9.1. Example partition setup Table 9.4. Example partition setup | Partition | Size and type |
|---|
/boot | 250 MB ext3 partition | swap | 2 GB swap | | LVM physical volume | Remaining space, as one LVM volume group |
The physical volume is assigned to the default volume group and divided into the following logical volumes: Table 9.5. Example partition setup: LVM physical volume | Partition | Size and type |
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/ | 13 GB ext4 | /var | 4 GB ext4 | /home | 50 GB ext4 |
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