[linux-lvm] No device found for PV but is actually fine

[Michal Svoboda <lvm@spatium.org>]

Hi all,

I have a weird issue:

# pvs
 No device found for PV JszGc1-S16s-bsFQ-weAl-aj8W-d6y4-BeVqcN.
 PV         VG    Fmt  Attr PSize   PFree
 /dev/sdc   data2 lvm2 a--  298.09g    0 
 /dev/sdd1  data  lvm2 a--  298.09g    0 

# pvscan 
  No device found for PV JszGc1-S16s-bsFQ-weAl-aj8W-d6y4-BeVqcN.
  No device found for PV JszGc1-S16s-bsFQ-weAl-aj8W-d6y4-BeVqcN.
  PV /dev/sdc    VG data2   lvm2 [298.09 GiB / 0    free]
  PV /dev/sdd1   VG data    lvm2 [298.09 GiB / 0    free]
  Total: 2 [596.18 GiB] / in use: 2 [596.18 GiB] / in no VG: 0 [0   ]

# pvscan --cache
  Found duplicate PV JszGc1S16sbsFQweAlaj8Wd6y4BeVqcN: using /dev/sde2 not /dev/md0
  Found duplicate PV JszGc1S16sbsFQweAlaj8Wd6y4BeVqcN: using /dev/sdf2 not /dev/sde2

The VG on the "missing" PV is called "system", but:

# vgdisplay /dev/system
  No device found for PV JszGc1-S16s-bsFQ-weAl-aj8W-d6y4-BeVqcN.
  --- Volume group ---
  VG Name               system
  System ID             
  Format                lvm2
  Metadata Areas        0
  Metadata Sequence No  28
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                8
  Open LV               8
  Max PV                0
  Cur PV                1
  Act PV                0
  VG Size               232.88 GiB
  PE Size               4.00 MiB
  Total PE              59616
  Alloc PE / Size       33792 / 132.00 GiB
  Free  PE / Size       25824 / 100.88 GiB
  VG UUID               fQoJ8p-BI3D-BcEH-BiQX-JJqf-p6TT-6KIoRt

Actually all LVs on the "system" VG are present and accounted for. The
LVs contain the root file system, and some virtual machine drives, all
of which are running *fine* (and the system in fact boots up from the
"missing" PV :). But I can't resize:

# lvextend -L +16G /dev/system/vm-monitor
  No device found for PV JszGc1-S16s-bsFQ-weAl-aj8W-d6y4-BeVqcN.
  Cannot change VG system while PVs are missing.
  Consider vgreduce --removemissing.

The "system" VG is situated on a md raid1. I think it all happened after
I replaced all the drives of that md with mdadm --replace with bigger
disks. But I can't be sure, because the system in fact works and except
the inability to resize there are no problems.

I have googled around a bit, but to no avail. Can someone help me
diagnose and repair this?

Version info:

# pvs --version
  LVM version:     2.02.105(2) (2014-01-20)
  Library version: 1.02.84 (2014-01-20)
  Driver version:  4.27.0

# cat /proc/version 
Linux version 3.14.0-4-ARCH (nobody@var-lib-archbuild-extra-x86_64-thomas) (gcc version 4.8.2 20140206 (prerelease) (GCC) ) #1 SMP PREEMPT Wed Apr 9 21:11:25 CEST 2014


Thanks,
Michal Svoboda