How to restore a ReaR backup after a multipath disk was replaced

Issue

• Recovering a system using ReaR when having a multipath disk with non-default device name (e.g. System instead of mpathX) after disk was replaced fails with the following error

  • rear recover output:

    # rear recover
    Relax-and-Recover 2.00 / Git
    Using log file: /var/log/rear/rear-mystem.log
    Running workflow recover within the ReaR rescue/recovery system
    Comparing disks.
    Disk configuration is identical, proceeding with restore.
    Start system layout restoration.
    Creating partitions for disk /dev/mapper/System (gpt)
    An error occurred during layout recreation.
    
    1) View Relax-and-Recover log
    2) View original disk space usage
    3) Go to Relax-and-Recover shell
    4) Edit restore script (diskrestore.sh)
    5) Continue restore script
    6) Abort Relax-and-Recover
    

  • rear log file:

    # cat /var/log/rear/rear-mysystem.log
    2018-01-19 13:51:51 Start system layout restoration.
    WARNING: Failed to connect to lvmetad. Falling back to device scanning.
    +++ create_component /dev/mapper/System multipath
    +++ local device=/dev/mapper/System
    +++ local type=multipath
    +++ local touchfile=multipath--dev-mapper-System
    +++ '[' -e /tmp/rear.YC1N4WQZ1IL0W8d/tmp/touch/multipath--dev-mapper-System ']'
    +++ return 0
    +++ LogPrint 'Creating partitions for disk /dev/mapper/System (gpt)'
    +++ Log 'Creating partitions for disk /dev/mapper/System (gpt)'
    +++ test 1 -gt 0
    ++++ Stamp
    ++++ date '+%Y-%m-%d %H:%M:%S '
    +++ echo '2018-01-19 13:51:51 Creating partitions for disk /dev/mapper/System (gpt)'
    2018-01-19 13:51:51 Creating partitions for disk /dev/mapper/System (gpt)
    +++ Print 'Creating partitions for disk /dev/mapper/System (gpt)'
    +++ test 1
    +++ echo -e 'Creating partitions for disk /dev/mapper/System (gpt)'
    +++ my_udevsettle
    +++ has_binary udevadm
    +++ for bin in '$@'
    +++ type udevadm
    +++ return 0
    +++ udevadm settle
    +++ parted -s /dev/mapper/System mklabel gpt
    Error: Could not stat device /dev/mapper/System - No such file or directory.
    2018-01-19 13:51:51 An error occurred during layout recreation.
    

• Migrating a system using ReaR to a different multipath disk with original disk not mapped to mpatha (e.g. disk was mapped to mpathc) fails with the following error

  • rear recover output:

    # rear recover
    Relax-and-Recover 2.00 / Git
    Using log file: /var/log/rear/rear-mystem.log
    Running workflow recover within the ReaR rescue/recovery system
    Comparing disks.
    Disk configuration is identical, proceeding with restore.
    Start system layout restoration.
    Creating partitions for disk /dev/mapper/mpathc (gpt)
    An error occurred during layout recreation.
    
    1) View Relax-and-Recover log
    2) View original disk space usage
    3) Go to Relax-and-Recover shell
    4) Edit restore script (diskrestore.sh)
    5) Continue restore script
    6) Abort Relax-and-Recover
    

  • rear log file:

    # cat /var/log/rear/rear-mysystem.log
    2018-01-19 13:51:51 Start system layout restoration.
    WARNING: Failed to connect to lvmetad. Falling back to device scanning.
    +++ create_component /dev/mapper/mpathc multipath
    +++ local device=/dev/mapper/mpathc
    +++ local type=multipath
    +++ local touchfile=multipath--dev-mapper-mpathc
    +++ '[' -e /tmp/rear.YC1N4WQZ1IL0W8d/tmp/touch/multipath--dev-mapper-mpathc ']'
    +++ return 0
    +++ LogPrint 'Creating partitions for disk /dev/mapper/mpathc (gpt)'
    +++ Log 'Creating partitions for disk /dev/mapper/mpathc (gpt)'
    +++ test 1 -gt 0
    ++++ Stamp
    ++++ date '+%Y-%m-%d %H:%M:%S '
    +++ echo '2018-01-19 13:51:51 Creating partitions for disk /dev/mapper/mpathc (gpt)'
    2018-01-19 13:51:51 Creating partitions for disk /dev/mapper/mpathc (gpt)
    +++ Print 'Creating partitions for disk /dev/mapper/mpathc (gpt)'
    +++ test 1
    +++ echo -e 'Creating partitions for disk /dev/mapper/mpathc (gpt)'
    +++ my_udevsettle
    +++ has_binary udevadm
    +++ for bin in '$@'
    +++ type udevadm
    +++ return 0
    +++ udevadm settle
    +++ parted -s /dev/mapper/mpathc mklabel gpt
    Error: Could not stat device /dev/mapper/mpathc - No such file or directory.
    2018-01-19 13:51:51 An error occurred during layout recreation.