Preparing Linux guest operating systems for transition

Contributors netapp-ivanad ntap-bmegan Download PDF of this page

If have 7-Mode LUNs mapped as physical compatible RDM (PTRDM) to Linux virtual machines (VMs) for the boot device, there are steps you must perform to prepare your Linux VMs for transition.

  • For copy-based transitions, perform these steps before initiating the Storage Cutover operation in the 7-Mode Transition Tool (7MTT).

  • For copy-free transitions, perform these steps before initiating the Export & Halt 7-Mode Systems operation in the 7MTT.

Steps
  1. Obtain the SCSI device serial numbers:

    cat /boot/grub/menu.lst

    In the following example, 360a9800032466879362b45777447462d-part2 and 360a9800032466879362b45777447462d-part1 are SCSI device numbers:

    # cat /boot/grub/menu.lst
    ...
    kernel /boot/vmlinuz-3.0.13-0.27-default root=/dev/disk/by-id/scsi-
    360a9800032466879362b45777447462d-part2 resume=/dev/disk/by-id/scsi-
    360a9800032466879362b45777447462d-part1
  2. Determine the mapping between the SCSI device serial numbers and SCSI devices/partitions:

    # ls -l /dev/disk/by-id

    The following example shows how the relationship mapping is displayed. The SCSI devices/partitions are displayed following the SCSI device/partition serial numbers. In this example, ../../sda, ../../sda1, and ../../sda2 are SCSI devices/partitions.

    lrwxrwxrwx 1 root root 9 Oct 27 06:54 scsi-360a9800032466879362b45777447462d -> ../../sda
       lrwxrwxrwx 1 root root 10 Oct 27 05:09 scsi-360a9800032466879362b45777447462d-part1 -> ../../sda1
       lrwxrwxrwx 1 root root 10 Oct 27 02:21 scsi-360a9800032466879362b45777447462d-part2 -> ../../sda2
  3. Determine the mapping between the SCSI device paths and the UUIDs:

    ls -l /dev/disk/by-uuid

    The following example shows how the relationship mapping is displayed. In this example, 33d43a8b-cfae-4ac4-9355-36b479cfa524 is the UUID for SCSI device/partition sda2`, 603e01f8-7873-440a-9182-878abff17143 is the UUID for SCSI device/partition sdb, and c50b757b-0817-4c19-8291-0d14938f7f0f is the UUID for SCSI device/partition sda1.

     lrwxrwxrwx 1 root root 10 Oct 27 02:21 33d43a8b-cfae-4ac4-9355-36b479cfa524 -> ../../sda2
       lrwxrwxrwx 1 root root 9 Oct 27 06:54 603e01f8-7873-440a-9182-878abff17143 -> ../../sdb
       lrwxrwxrwx 1 root root 10 Oct 27 05:09 c50b757b-0817-4c19-8291-0d14938f7f0f -> ../../sda1
  4. Use the UUID to update the device reference in the grub boot menu.lst file by matching it with the SCSI device path and SCSI serial number.

    #blkid
    /dev/sda1: UUID="c50b757b-0817-4c19-8291-0d14938f7f0f" TYPE="swap"
    /dev/sda2: UUID="33d43a8b-cfae-4ac4-9355-36b479cfa524" TYPE="ext3"
    /dev/sdb: UUID="603e01f8-7873-440a-9182-878abff17143" SEC_TYPE="ext2" TYPE="ext3"
  5. Use the UUID you just retrieved to update the device reference in the grub boot menu.lst file.

    The following example shows the menu.lst file after it has been updated:

    # Modified by YaST2. Last modification on Fri Oct 17 02:08:40 EDT 2014
    default 0
    timeout 8
    ##YaST - generic_mbr
    gfxmenu (hd0,1)/boot/message
    ##YaST - activate
    ###Don't change this comment - YaST2 identifier: Original name: linux###
    title SUSE Linux Enterprise Server 11 SP2 - 3.0.13-0.27
    root (hd0,1)
    kernel /boot/vmlinuz-3.0.13-0.27-default root=/dev/disk/by-uuid/e5127cdf-8b30-
    418e-b0b2-35727161ef41 resume=/dev/disk/by-uuid/d9133964-d2d1-4e29-b064-7316c5ca5566
    splash=silent crashkernel=128M-:64M showopts vga=0x314
    initrd /boot/initrd-3.0.13-0.27-default
  6. Update the /etc/fstab file:

    1. Use the UUID you just retrieved to update the device reference in the /etc/fstab file.

      The following example shows an /etc/fstab file with a SCSI serial number:

      /dev/disk/by-id/scsi-360a9800032466879362b45777447462d-part1 swap swap
      defaults 0 0
      /dev/disk/by-id/scsi-360a9800032466879362b45777447462d-part2 / ext3
      acl,user_xattr 1 1
      proc /proc proc defaults 0 0
      sysfs /sys sysfs noauto 0 0
      debugfs /sys/kernel/debug debugfs noauto 0 0
      devpts /dev/pts devpts mode=0620,gid=5 0 0
    2. Replace the reference to the SCSI serial number with the UUID.

      The following example shows an /etc/fstab file that has been updated to replace the SCSI serial number with the UUID:

      cat /etc/fstab
      UUID="c50b757b-0817-4c19-8291-0d14938f7f0f swap swap defaults
      0 0
      UUID="33d43a8b-cfae-4ac4-9355-36b479cfa524 / ext3 acl,user_xattr
      1 1
      proc /proc proc defaults 0 0
      sysfs /sys sysfs noauto 0 0
      debugfs /sys/kernel/debug debugfs noauto 0 0
      devpts /dev/pts devpts mode=0620,gid=5 0 0