LVM PV excluded with error device is a multipath component

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Environment

SUSE Linux Enterprise Server 15 SP5

SUSE Linux Enterprise Server 15 SP6

Situation

The server was upgraded from SLE 15 SP3 LTSS to SLE 15 SP5, after reboot, the Volume Group is not getting activated and some Physical Volumes are missing.

srv1:~ # pvs
  WARNING: Couldn't find device with uuid RhZ9ee-0M5r-MZ8D-RS5j-7PTG-BHzi-WsvjQQ.
  WARNING: VG mainvg is missing PV RhZ9ee-0M5r-MZ8D-RS5j-7PTG-BHzi-WsvjQQ (last written to /dev/sdb).
  WARNING: Couldn't find all devices for LV mainvg/lv01 while checking used and assumed devices.
  PV         VG     Fmt  Attr PSize    PFree
  /dev/sdc   mainvg lvm2 a--  1020.00m 92.00m
  [unknown]  mainvg lvm2 a-m     2.00g     0

Using blkid the device is presented in the system:

srv1:~ # blkid /dev/sdb
/dev/sdb: UUID="RhZ9ee-0M5r-MZ8D-RS5j-7PTG-BHzi-WsvjQQ" TYPE="LVM2_member"

Resolution

Remove the disk UUID from /etc/multipath/wwids file.

The command multipath -w <UUID> can be used or simply use a text editor.

After that run: pvscan --cache to scan the PV again:

srv1:~ # pvscan --cache
  pvscan[5742] PV /dev/sdb online.
  pvscan[5742] PV /dev/sdc online.

srv1:~ # pvs
  PV         VG     Fmt  Attr PSize    PFree
  /dev/sdb   mainvg lvm2 a--     2.00g     0
  /dev/sdc   mainvg lvm2 a--  1020.00m 92.00m

Cause

Looking into journalctl using the following command journalctl -b _COMM=lvm

srv1:~ # journalctl -b _COMM=lvm
Apr 14 10:17:03 srv1 lvm[631]:   WARNING: Couldn't find device with uuid RhZ9ee-0M5r-MZ8D-RS5j-7PTG-BHzi-WsvjQQ.
Apr 14 10:17:03 srv1 lvm[631]:   WARNING: VG mainvg is missing PV RhZ9ee-0M5r-MZ8D-RS5j-7PTG-BHzi-WsvjQQ (last written to /dev/sdb).
Apr 14 10:17:05 srv1 lvm[712]: PV /dev/sdc online, VG mainvg incomplete (need 1).
Apr 14 10:17:05 srv1 lvm[710]: /dev/sdb excluded: device is a multipath component.

We can see the main reason for excluding the device. Looking into mulitpath configuration:

srv1:~ # ll /dev/disk/by-id/scsi-3*|grep sdb
lrwxrwxrwx 1 root root  9 Apr 14 10:17 /dev/disk/by-id/scsi-36000c29af0de29b577c358dae9e33c54 -> ../../sdb

srv1:~ # cat /etc/multipath/wwids | grep -v "^#"
/36000c29af0de29b577c358dae9e33c54/

The Disk UUID is stored in the wwids, preventing it from being used by LVM.

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