Bug#691608: lvm2: Unable to extend LVM2 RAID5 partition created with --type raid5

[Edward C. Lang]

Package: lvm2
Version: 2.02.95-4
Severity: normal


This is a bug in LVM2 running on a freshly installed Debian 6.0.6 system 
that was then immediately upgraded to testing. 

root at lettuce:/# lvcreate --type raid5 -i3 -L 10GiB -n test_raid5 lettuce
  Using default stripesize 64.00 KiB
  Rounding size (160 extents) up to stripe boundary size (162 extents)
  Logical volume "test_raid5" created
root at lettuce:/# lvdisplay lettuce/test_raid5
  --- Logical volume ---
  LV Path                /dev/lettuce/test_raid5
  LV Name                test_raid5
  VG Name                lettuce
  LV UUID                LcZhEP-uX5I-vg9y-2hUN-TROs-gRZV-QM5Tm8
  LV Write Access        read/write
  LV Creation host, time lettuce, 2012-10-28 01:49:20 +1100
  LV Status              available
  # open                 0
  LV Size                10.12 GiB
  Current LE             162
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     1024
  Block device           254:33

root at lettuce:/# lvextend -L +10GiB lettuce/test_raid5
  Extending logical volume test_raid5 to 20.12 GiB
  Internal error: _alloc_init called for non-virtual segment with no disk space.
root at lettuce:/# lvm version
  LVM version:     2.02.95(2) (2012-03-06)
  Library version: 1.02.74 (2012-03-06)
  Driver version:  4.22.0

Relevant output from dmesg:

[ 1018.116621] device-mapper: raid: Superblocks created for new array
[ 1018.136202] md/raid:mdX: not clean -- starting background reconstruction
[ 1018.136232] md/raid:mdX: device dm-32 operational as raid disk 3
[ 1018.136240] md/raid:mdX: device dm-30 operational as raid disk 2
[ 1018.136246] md/raid:mdX: device dm-28 operational as raid disk 1
[ 1018.136251] md/raid:mdX: device dm-26 operational as raid disk 0
[ 1018.137297] md/raid:mdX: allocated 4280kB
[ 1018.137456] md/raid:mdX: raid level 5 active with 4 out of 4 devices, algorithm 2
[ 1018.137464] RAID conf printout:
[ 1018.137470]  --- level:5 rd:4 wd:4
[ 1018.137476]  disk 0, o:1, dev:dm-26
[ 1018.137481]  disk 1, o:1, dev:dm-28
[ 1018.137486]  disk 2, o:1, dev:dm-30
[ 1018.137491]  disk 3, o:1, dev:dm-32
[ 1018.137501] Choosing daemon_sleep default (5 sec)
[ 1018.137506] created bitmap (4 pages) for device mdX
[ 1018.176462] mdX: bitmap file is out of date, doing full recovery
[ 1018.184818] mdX: bitmap initialized from disk: read 1/1 pages, set 6912 of 6912 bits
[ 1018.194336] md: resync of RAID array mdX
[ 1018.194345] md: minimum _guaranteed_  speed: 1000 KB/sec/disk.
[ 1018.194351] md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for resync.
[ 1018.194365] md: using 128k window, over a total of 3538944k.
[ 1088.249766] md: mdX: resync done.
[ 1088.286216] RAID conf printout:
[ 1088.286225]  --- level:5 rd:4 wd:4
[ 1088.286232]  disk 0, o:1, dev:dm-26
[ 1088.286238]  disk 1, o:1, dev:dm-28
[ 1088.286243]  disk 2, o:1, dev:dm-30
[ 1088.286247]  disk 3, o:1, dev:dm-32

Other information:

root at lettuce:/# vgdisplay lettuce
  --- Volume group ---
  VG Name               lettuce
  System ID
  Format                lvm2
  Metadata Areas        4
  Metadata Sequence No  57
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                11
  Open LV               4
  Max PV                0
  Cur PV                4
  Act PV                4
  VG Size               10.92 TiB
  PE Size               64.00 MiB
  Total PE              178848
  Alloc PE / Size       44627 / 2.72 TiB
  Free  PE / Size       134221 / 8.19 TiB
  VG UUID               fXqFmJ-1LEq-uf3v-eySJ-vlG9-oC1d-I4Y0SI

root at lettuce:/# pvs
  PV         VG      Fmt  Attr PSize PFree
  /dev/sda2  lettuce lvm2 a--  2.73t  2.73t
  /dev/sdb2  lettuce lvm2 a--  2.73t 34.12g
  /dev/sdc2  lettuce lvm2 a--  2.73t  2.71t
  /dev/sdd2  lettuce lvm2 a--  2.73t  2.73t


-- System Information:
Debian Release: 6.0.6
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 3.4.2-linode44 (SMP w/4 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash