| Installation Guide16.12. Assign Storage Devices If you selected more than one storage device on the storage devices selection screen (refer to Section 16.8, "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 16.15, "Disk Partitioning Setup"). When you have finished identifying devices to be used for installation, click Next to continue. 16.13. 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. 16.14. 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. 16.14.1. 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. 16.14.2. 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. 16.15. 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 11.6, "Do You Have Enough Disk Space?". - 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. 16.16. Encrypt Partitions 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. 16.17. 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. 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 16.12, " 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.
16.17.2. 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 16.17.2.1, "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.
16.17.2.1. 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.
16.17.3. 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 16.17.2, "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.
16.17.4. 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 16.17.2, "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.
16.17.5. Recommended Partitioning SchemeUnless you have a reason for doing otherwise, we recommend that you create the following partitions: 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 16.2. Recommended System Swap Space | Amount of RAM in the system | Recommended swap space | Recommended swap space if allowing for hibernation |
|---|
| ⩽ 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. A PReP boot partition on the first partition of the hard drive - the PReP boot partition contains the Yaboot boot loader (which allows other Power Systems servers to boot Red Hat Enterprise Linux). Unless you plan to boot from a network source, you must have a PReP boot partition to boot Red Hat Enterprise Linux. For IBM System p users: The PReP boot partition should be between 4-8 MB, not to exceed 10 MB. A /boot/ partition (250 MB) - the partition mounted on /boot/ contains the operating system kernel (which allows your system to boot Red Hat Enterprise Linux), along with files used during the bootstrap process. Due to the limitations of most PC firmware, creating a small partition to hold these is a good idea. For most users, a 250 MB boot partition is sufficient. If you have a RAID card, be aware that Red Hat Enterprise Linux 6 does not support setting up hardware RAID on an IPR card. You can boot the standalone diagnostics CD prior to installation to create a RAID array and then install to that RAID array. 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 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. 16.18. Write changes to diskThe installer prompts you to confirm the partitioning options that you selected. Click Write changes to disk to allow the installer to partition your hard drive and install Red Hat Enterprise Linux. If you are certain that you want to proceed, click Write changes to disk. Up to this point in the installation process, the installer has made no lasting changes to your computer. When you click Write changes to disk, the installer will allocate space on your hard drive and start to transfer Red Hat Enterprise Linux into this space. Depending on the partitioning option that you chose, this process might include erasing data that already exists on your computer. To revise any of the choices that you made up to this point, click Go back. To cancel installation completely, switch off your computer. After you click Write changes to disk, allow the installation process to complete. If the process is interrupted (for example, by you switching off or resetting the computer, or by a power outage) you will probably not be able to use your computer until you restart and complete the Red Hat Enterprise Linux installation process, or install a different operating system. 16.19. Package Group SelectionNow that you have made most of the choices for your installation, you are ready to confirm the default package selection or customize packages for your system. The Package Installation Defaults screen appears and details the default package set for your Red Hat Enterprise Linux installation. This screen varies depending on the version of Red Hat Enterprise Linux you are installing. If you install Red Hat Enterprise Linux in text mode, you cannot make package selections. The installer automatically selects packages only from the base and core groups. These packages are sufficient to ensure that the system is operational at the end of the installation process, ready to install updates and new packages. To change the package selection, complete the installation, then use the Add/Remove Software application to make desired changes. By default, the Red Hat Enterprise Linux installation process loads a selection of software that is suitable for a system deployed as a basic server. Note that this installation does not include a graphical environment. To include a selection of software suitable for other roles, click the radio button that corresponds to one of the following options: - Basic Server
This option provides a basic installation of Red Hat Enterprise Linux for use on a server. - Database Server
This option provides the MySQL and PostgreSQL databases. - Web server
This option provides the Apache web server. - Enterprise Identity Server Base
This option provides OpenLDAP and Enterprise Identity Management (IPA) to create an identity and authentication server. - Virtual Host
This option provides the KVM and Virtual Machine Manager tools to create a host for virtual machines. - Desktop
This option provides the OpenOffice.org productivity suite, graphical tools such as the GIMP, and multimedia applications. - Software Development Workstation
This option provides the necessary tools to compile software on your Red Hat Enterprise Linux system. - Minimal
This option provides only the packages essential to run Red Hat Enterprise Linux. A minimal installation provides the basis for a single-purpose server or desktop appliance and maximizes performance and security on such an installation.
To customize your package set further, select the Customize now option on the screen. Clicking Next takes you to the Package Group Selection screen. 16.19.1. Installing from Additional RepositoriesYou can define additional repositories to increase the software available to your system during installation. A repository is a network location that stores software packages along with metadata that describes them. Many of the software packages used in Red Hat Enterprise Linux require other software to be installed. The installer uses the metadata to ensure that these requirements are met for every piece of software you select for installation. The Red Hat Enterprise Linux repository is automatically selected for you. It contains the complete collection of software that was released as Red Hat Enterprise Linux 6, with the various pieces of software in their versions that were current at the time of release. To include software from extra repositories, select Add additional software repositories and provide the location of the repository. To edit an existing software repository location, select the repository in the list and then select Modify repository. If you change the repository information during a non-network installation, such as from a Red Hat Enterprise Linux DVD, the installer prompts you for network configuration information. Select an interface from the drop-down menu. Click OK.
Anaconda activates the interface that you selected, then starts NetworkManager to allow you to configure the interface. If you select Add additional software repositories, the Edit repository dialog appears. Provide a Repository name and the Repository URL for its location. Once you have located a mirror, to determine the URL to use, find the directory on the mirror that contains a directory named repodata. Once you provide information for an additional repository, the installer reads the package metadata over the network. Software that is specially marked is then included in the package group selection system. If you choose Back from the package selection screen, any extra repository data you may have entered is lost. This allows you to effectively cancel extra repositories. Currently there is no way to cancel only a single repository once entered. 16.19.2. Customizing the Software Selection Your Red Hat Enterprise Linux system automatically supports the language that you selected at the start of the installation process. To include support for additional languages, select the package group for those languages from the Languages category. Users who want support for developing or running 64-bit applications are encouraged to select the Compatibility Arch Support and Compatibility Arch Development Support packages to install architecture specific support for their systems. Select Customize now to specify the software packages for your final system in more detail. This option causes the installation process to display an additional customization screen when you select Next. Red Hat Enterprise Linux divides the included software into package groups. For ease of use, the package selection screen displays these groups as categories. You can select package groups, which group components together according to function (for example, X Window System and Editors), individual packages, or a combination of the two. To view the package groups for a category, select the category from the list on the left. The list on the right displays the package groups for the currently selected category. To specify a package group for installation, select the check box next to the group. The box at the bottom of the screen displays the details of the package group that is currently highlighted. None of the packages from a group will be installed unless the check box for that group is selected. If you select a package group, Red Hat Enterprise Linux automatically installs the base and mandatory packages for that group. To change which optional packages within a selected group will be installed, select the Optional Packages button under the description of the group. Then use the check box next to an individual package name to change its selection. In the package selection list on the right, you can use the context menu as a shortcut to select or de-select base and mandatory packages or all optional packages. After you choose the desired packages, select Next to proceed. The installer checks your selection, and automatically adds any extra packages required to use the software you selected. When you have finished selecting packages, click Close to save your optional package selections and return to the main package selection screen. The packages that you select are not permanent. After you boot your system, use the Add/Remove Software tool to either install new software or remove installed packages. To run this tool, from the main menu, select ⤍ ⤍ . The Red Hat Enterprise Linux software management system downloads the latest packages from network servers, rather than using those on the installation discs. 16.19.2.1. Core Network Services All Red Hat Enterprise Linux installations include the following network services: centralized logging through syslog email through SMTP (Simple Mail Transfer Protocol) network file sharing through NFS (Network File System) remote access through SSH (Secure SHell) resource advertising through mDNS (multicast DNS)
The default installation also provides: network file transfer through HTTP (HyperText Transfer Protocol) printing through CUPS (Common UNIX Printing System) remote desktop access through VNC (Virtual Network Computing)
Some automated processes on your Red Hat Enterprise Linux system use the email service to send reports and messages to the system administrator. By default, the email, logging, and printing services do not accept connections from other systems. Red Hat Enterprise Linux installs the NFS sharing, HTTP, and VNC components without enabling those services. You may configure your Red Hat Enterprise Linux system after installation to offer email, file sharing, logging, printing and remote desktop access services. The SSH service is enabled by default. You may use NFS to access files on other systems without enabling the NFS sharing service. 16.20. Installing PackagesAt this point there is nothing left for you to do until all the packages have been installed. How quickly this happens depends on the number of packages you have selected and your computer's speed. Depending on the available resources, you might see the following progress bar while the installer resolves dependencies of the packages you selected for installation: During installation of the selected packages and their dependencies, you see the following progress bar: 16.21. Installation CompleteCongratulations! Your Red Hat Enterprise Linux installation is now complete! The installation program prompts you to prepare your system for reboot. Remember to remove any installation media if it is not ejected automatically upon reboot. After your computer's normal power-up sequence has completed, Red Hat Enterprise Linux loads and starts. By default, the start process is hidden behind a graphical screen that displays a progress bar. Eventually, a login: prompt or a GUI login screen (if you installed the X Window System and chose to start X automatically) appears. The first time you start your Red Hat Enterprise Linux system in run level 5 (the graphical run level), the FirstBoot tool appears, which guides you through the Red Hat Enterprise Linux configuration. Using this tool, you can set your system time and date, install software, register your machine with Red Hat Network, and more. FirstBoot lets you configure your environment at the beginning, so that you can get started using your Red Hat Enterprise Linux system quickly. |
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