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  • 1.  Migrate SLES12 root on btrfs to new disk

    Posted Thu June 06, 2024 04:50 AM

    Hello,

    We have a number of SLES12 LPARs which, by default, have the root file system on btrfs

    We're migrating to newer storage so we're looking at how we can migrate the btrfs root file system to the new disk.

    My preference would be to use the storage to migrate the boot volume but this will change the UUID of the boot volume and prevent the LPAR from booting.

    What is the safest method of migrating a btrfs volume to a new disk



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    Glenn Robinson
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  • 2.  RE: Migrate SLES12 root on btrfs to new disk

    Posted Fri June 07, 2024 02:50 AM
    Edited by Andre Lutz Fri June 07, 2024 02:50 AM

    Hello Glenn,

    There are many ways in the Linux environment. 
    BTRFS is already good for updates from SLES Update. -> Inplace Update, because BTRFS works with snapshots and you can rollback with snapper command. 

    To migrate to another disk, the best combination is LVM + BTRFS. 

    Can you send me the output of this command? (root disk) 

    lsblk -o name,type,fstype,size,mountpoint,uuid



    ------------------------------
    Andre Lutz
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    Original Message


  • 3.  RE: Migrate SLES12 root on btrfs to new disk

    Posted Fri June 07, 2024 03:29 AM

    Thanks Andre.

    i have uploaded a file with the output you requested.



    ------------------------------
    Glenn Robinson
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    Original Message


  • 4.  RE: Migrate SLES12 root on btrfs to new disk

    Posted Fri June 07, 2024 08:38 AM

    Hello Glenn,

    use lvm to move the rootvg(system) from one disk to the other.

    Here is a rough procedure. You should do this with a test system and make a backup before. 


    Reboot is also recommended. This action can be carried out while the system is running

    sfdisk -l /dev/sda > svc_bootdisk.out

    HD=sdxxx # new disk
    sfdisk $HD < svc_bootdisk.out
    blockdev --rereadpt $HD

    PV=/dev/dm-xxxx
    pvscan
    pvcreate $PV
    pvscan
    vgs
    vgextend system $PV
    pvs

    pvmove --atomic /dev/dm-old  /dev/dm-new

    # lvs -a -o +devices view
    vgreduce system /dev/dm-old
    pvremove /dev/dm-old

    grub2-install /dev/disk/by-id/dm-new-part1
    grub2-mkconfig -o /boot/grub2/grub.cfg
    systemctl daemon-reload
    mkinitrd

    bootlist -m normal sdan sdal sdaq sdai
    bootlist -m normal -r


    ------------------------------
    Andre Lutz
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    Original Message


  • 5.  RE: Migrate SLES12 root on btrfs to new disk

    Posted Sun June 09, 2024 05:06 PM

    Thank you, this makes sense.

    I assume the svc_bootdisk.out file does not need to be edited before using the following command?

    sfdisk $HD < svc_bootdisk.out



    ------------------------------
    Glenn Robinson
    ------------------------------

    Original Message


  • 6.  RE: Migrate SLES12 root on btrfs to new disk

    Posted Mon June 10, 2024 05:18 AM

    No does not need to be edited if the hard disk is the same size and the layout should remain the same. 



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    Andre Lutz
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    Original Message