Upgrading To Red Hat Enterprise Linux 6

This document describes the upgrade and configuration of Red Hat Enterprise Linux Version 5 to version 6.

Red Hat Enterprise Linux Version 5/6 will require that the existing host to have the following characteristics:

• The host must have disk storage of at least 80GB,
• The host must have memory storage of at least 2GB,
• The host must be able to boot from the network (using PXE) or CD/DVD.
• The host must be 64-bit

If the existing Red Hat Enterprise Linux 6 host does not meet the minimum requirements, it must be considered for retirement.

Stop ACmaint

Stop ACmaint from sending updates to the host during the upgrade. Use the ACmaint's ah utility with the command:

ah> modify host somehost state d

Stop Backups

If the host has a definition in igor or either OMNI_SERVER or NETBACKUP_SERVER, then it is likely that the host is on backup service.

If backup services are enabled on the host, be sure to inform the backup staff of the operating system change. Have them stop backups. Optionally have them do a full backup before starting the upgrade. You should also inform them if the hard drive was reformated.

Dumping Existing Filesystems

If the system is without backup services, or if the backup staff cannot do a full backup before the upgrade, it may be necessary to save off certain parts of an existing host's filesystems. Save anything unique to that machine such as:

• Home partitions (/export/home/a, /export/home/b, etc.),
• Mailboxes (/var/spool/mail).
• Scratch partitions (/export/home/scratch, /export/scratch/a, /var/scratch, /var/local/scratch, etc...)
• Local data spaces (/var/local/stuff, /var/local/<user>, etc...)

Also, check to see if there is software unique to the machine, or local file storage. Places to check include:

• /opt for packages not rdist'ed nor installed via RPM.
• /var for paths not rdist'ed.
• And especially, /var/local.

A sample command to save files of a partition to a scratch space on AdicTwo would be:

# exportfs -v -u -a
# umount /export/home/a
# dump -0 -a -f - /export/home/a | gzip -c |
> ssh username@adictwo 'cat >/cache/tempsaves/somehost.a.dump.gz'

Note: Be sure to ask the backup staff if it's okay to use the storage space on AdicTwo. Be sure to clean up the temporary backups periodically to free disk space. Properly set the permissions on the temporary space to avoid disclosing data.

Updating Igor

Update igor settings. Go to the igor hosts directory at harbor:/usr/share/adm/igor/hosts and edit the site file. In particular, make the following changes:

» If the host has an NVidia video card and you want to use the proprietary 3D display driver, update the NVIDIA definition to the latest version available for RH6. Check other RH6 NVIDIA versions settings to see what that version number is. Some older hardware will require a legacy driver, defined as NVIDIA_DRIVER. So far, the only legacy hardware that requires the NVIDIA_DRIVER is the NVidia GeoForce FX 5200 card in Dell OptiPlex 270 workstations. Refer to the document /opt/nvidia2/current/usr/share/doc/README.txt for a list of graphics cards that need the legacy driver.

» If the host has an ATI video card and you want to use the proprietary 3D display driver, add the igor definition ATI_DRIVER.

Updating rdist

Go to the rdist hosts directory at harbor:/var/rdist/hosts and edit the site file by by removing the host from the LINUX_RHEL5 variable, and placing it in the coresponding LINUX_RHEL6 variable (either LINUX_RHEL6_STANDALONE or LINUX_RHEL6_HOMESERVER).

Save Files

Update the system's solsave files. Doing an update now will make sure that the host's unique files will be safely migrated to the new operating system.

On harbor run the following command:

# ssh somehost -n /usr/share/adm/igor/bin/savefiles

This places the newly created database files on the ftp server, Jetty. Next, run the following command to import the files from Jetty to the solsave repositary:

# ~solsave/bin/savefiles.cron

Verify that the file updated by checking the date on the file:

# ls -l ~solsave/somehost.tar.gz

Build Kickstart

NOTE! For security purposes, the kickstart files are removed at 6pm, 12midnight and 6am. Be sure to deploy the host immediately after building the kickstart files - else the deploy will have to be redone.

Create the kickstart files for the host. Building the kickstart file will allow for the host to automatically boot and install Red Hat Enterprise Linux 5.

Go to harbor:/var/local/install_rh6/clients and run the kickstart configuration command:

# cd /var/local/install_rh6/clients
# ./build-ks somehost

The most noteworthy option is -f. If either kickstart or state file exists, the build script will not overwrite these files. Use -f to overwrite the existing files.

There are many options available when making the kickstart script.

Usage: ./build-ks [flags...] hostname
  -f|--force        Force or overwrite of existing files
  -V|--verbose      Verbose

  -i|--interactive  Process kickstart in 'interactive' mode

  -H|--homeserver   Build a HOMESERVER system (autodetect)
  -S|--standalone   Build a STANDALONE system (autodetect)

  -c|--client       Use client installation key (default)
  -s|--server       Use server installation key

  -t|--text         Kickstart in text mode (Default is: graphical mode)
  -x|--nox          Boot to text console (Default is: graphical console)

  --rootsize=n      Sets the root filesystem size to 'n' GB (default: 16)
  --swapsize=n      Sets the swap size to 'n' GB (default: 8)
  --varsize=n       Sets the var filesystem size to 'n' GB (default 4)
  -p|--preserve     Preserve disk structure

Most of the default settings for build-ks will be sufficient. The default is to do a graphical install with all partitions set to a default size. It also sets the display to be graphical when the workstation boots. A home filesystem will be built if the host has an igor variable HOMESERVER, otherwise the /var filesystem will collect most of the disk space.

When moving from Red Hat Enterprise Linux 5 to version 6, the partition sizes change for the root and var filesystems.

Upgrade

The steps for performing the update are the following:

• Start the kickstart installation. Boot the host and select the CD/DVD or PXE (network) as the boot device.
• The system will boot and install Red Hat Enterprise Linux 6. If you've asked for an interactive install, or asked for manual disk partitioning, the console will prompt for input. Otherwise, the installation will proceed automatically. After the install, the system will reboot.
• When the system boots, it will run through its normal boot scripts, but will stop at the ecnfirstboot script and pause for about 30 minutes. When the script completes, it will proceed to the login screen. After about 30 seconds, it will reboot again.
• At the login screen, log on as root using the installation root password. Check the log file for errors.

There "should" be mail that goes to the redhat5 queue that says when the system has completed the installation, and will include a copy of the log file.

PXE

When booting using the network, set or enable the host to boot PXE. Each PC BIOS uses a different method for setting up booting with PXE. Consult the PC's documentation, or poke around in the setup until you find the network settings and change appropriately.

Start the PC booting, selecting the boot device to be PXE. PXE will contact the  DHCP server and request a download for the ECN Network Boot Menu.  If the setup for an upgrade was done properly the machine will appear on the bottom menu item.

If the PC has more than 2 CPU sockets (with a maximum of eight CPU cores), then the AS version will be required. Otherwise choose WS. Also, be aware that some applications are available only in the WS version, such as Thunderbird, so choose WS for desktop interactive systems.

If you are doing a custom install the press the TAB button. A prompt for a password will appear. Enter the deployment password and press RETURN.

If everything goes okay, the system will load Red Hat Enterprise Linux version 6 and begin to install. The installation will take about 30 minutes to complete.

CD/DVD (RH5 example)

CD installations are possible by creating the boot CD from one of the CD disk image files (ISO) located at harbor:/var/local/install_rh5/rh5. Choose the first disk of the series. For example, use the file:

harbor:/var/local/install_rh5/rh5/rhel-5-client-i386-disc1.iso

to install the 32-bit version of the Red Hat Enterprise Linux 5 client. Be sure to check periodically to see if a newer version of the CD is available.

When booting using the CD/DVD, set or enable the host to boot from the CD/DVD drive. Place the CD into the drive and begin booting. After about a minute, the boot prompt will appear on the screen.

At the prompt, enter the following boot command:

linux ks=nfs:harbor:/var/local/install_rh5/kickstart/somehost.ks

If everything goes okay, the system will load Red Hat Enterprise Linux version 5 and begin to install. The installation will take about 30 minutes to complete. Be sure to remove the CD/DVD once the installation begins.

Install Complete

Wait for the install to complete and check the log file for errors.

Restore Filesystems

Restore all filesystems and unique software and local file storage as required.

A sample command to restore files to a partition from AdicTwo would be:

# cd /export/home/a
# ssh username@adictwo 'cat /cache/tempsaves/somehost.a.dump.gz' |
> gunzip -c |
> restore rf -

ACmaint

After the upgrade is complete, update all of the accounts on the host by running a "build password files" command in ACmaint's ah utility:

ah> purge queue somehost
ah> buildPasswdFiles somehost
ah> modify host somehost state u

Be sure to wait for changes to complete! Check the number of packets left to process using the ACmaint's ah utility with the command:

ah> show host somehost packet_count

If packets are stalling, check the log file on the newly installed system at /var/log/transd_log to see what is causing the delay. Common errors are invalid host keys or problems mounting the home filesystem for an account. All ACmaint packets must go through before proceeding.

Quotas

Systems with home directories will need to have their quotas restored. Use the ACmaint system to place quotas for each user.

Extract a list of quota commands from the ecndb database. There is a script to do this called ah-quota.

$ /var/ecndb/bin/ah-quota somehost >quotas.ah
$ ah
ah> readscript quotas.ah

Once the packets have transfered, check the quotas or /var/log/transd_log file to make sure the quotas were set.

Start Backups

If backup services were stopped above, be sure to inform the backup staff to restart backups and do a full backup. Be sure to indicate any filesystem changes made during the upgrade.

Red Hat Network

The Red Hat Network records a host by operating system version. The upgrade will leave a duplicate host in the Red Hat Network database with the previous operating system version. Remove the duplicate host from the support database.