snapshots can't be deactivated

linux-lvm Falko Zurell 4 participants 6 messages Jul 17, 2007 – Jul 20, 2007

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Falko Zurell

author

2007-07-17 14:33 UTC #0 lore raw

Hello list,

I have a strange behaviour on my snapshots.
I got a Ubuntu Server 7.04 with LVM2 setup:

lvm> version
LVM version: 2.02.06 (2006-05-12)
Library version: 1.02.08 (2006-07-17)
Driver version: 4.11.0

I have two logical volumes I want to make snapshots of every night:

/dev/vg0/home with XFS
/dev/vg0/opt with XFS

These snapshots will be mounted read-only under /backup

So in principle the steps to achieve this should be:

- unmount the snapshot from yesterday (umount /backup/home)
- discard the snapshot from yesterday (lvremove -f
/dev/vg0/daily-snapshot-home)
- freeze the filesystem (xfs_freeze -f /dev/vg0/home)
- create the snapshot (lvcreate --snapshot --size 20G --name
daily-snap-home -v /dev/vg0/home)
- unfreeze the filesystem (xfs_freeze -u /dev/vg0/home)
- mount the new snapshot ro (mount -oro,nouuid
/dev/vg0/daily-snap-home /backup/home)

I wrote a script for that with some error checking too. But sometimes this doesn't work. The problem seems to be that the snapshot isn't removed even if "lvremove -f " sais it is removed. I got the following error message when I then recreate the snapshot:

root@konrad:~# ./create-snapshot-home.sh
+ /sbin/lvs
  LV              VG   Attr   LSize   Origin Snap%  Move Log Copy%
  daily-snap-home vg0  swi-ao  20.00G home     0.00
  daily-snap-opt  vg0  swi-ao  20.00G opt      0.08
  home            vg0  owi-ao 100.00G
  opt             vg0  owi-ao 100.00G
  root            vg0  -wi-ao  10.00G
  video           vg0  -wi-ao 800.00G
+ /bin/umount -f /backup/home
+ /sbin/lvdisplay
+ grep /dev/vg0/daily-snap-home
                         /dev/vg0/daily-snap-home [active]
  LV Name                /dev/vg0/daily-snap-home
+ [ 0 -eq 0 ]
+ [ -b /dev/mapper/vg0-daily--snap--home ]
+ /sbin/lvremove -f /dev/vg0/daily-snap-home
  Logical volume "daily-snap-home" successfully removed
+ sleep 5
+ [ -b /dev/mapper/vg0-daily--snap--home ]
+ [ 0 -eq 0 ]
+ /usr/sbin/xfs_freeze -f /home
+ [ 0 -eq 0 ]
+ /sbin/lvcreate --snapshot --size 20G --name daily-snap-home -v /dev/vg0/home
    Setting chunksize to 16 sectors.
    Finding volume group "vg0"
    Archiving volume group "vg0" metadata (seqno 116).
    Creating logical volume daily-snap-home
    Creating volume group backup "/etc/lvm/backup/vg0" (seqno 117).
    Found volume group "vg0"
    Creating vg0-daily--snap--home
    Loading vg0-daily--snap--home table
    Resuming vg0-daily--snap--home (254:5)
    Clearing start of logical volume "daily-snap-home"
    Found volume group "vg0"
  LV vg0/daily-snap-home in use: not deactivating
  Couldn't deactivate new snapshot.
+ /usr/sbin/xfs_freeze -u /home
+ /bin/mount -oro,nouuid /dev/vg0/daily-snap-home /backup/home
mount: you must specify the filesystem type

I don't know why this happens. The script will work perfectly 3 out of 5 times. But sometimes it comes up with the error above.

Are my steps right in principle? Did I forget to do something before or after removing?

Thanks and kind regards

Signature · 22 lines

Falko Zurell
Head of Application Management


/i-d media AG
Ohlauer Straï¿½e 43
D-10999 Berlin

Tel +49 (0)30 - 2 59 47 - 357
Fax +49 (0)30 - 2 59 47 - 471
www.idmedia.com

_______________________________________________

Board: Regine Haschka-Helmer (CEO), Franz Klose (CFO)
Chairman of the Supervisory Board: Christian A. Hufnagl
Headquarters: Berlin, Place of Jurisdiction: Berlin HRB 76342
UST-Id. DE812698340
_______________________________________________


This message may contain confidential information and must not be copied, disclosed or used by anybody other than the intended recipient. If you have received this message in error, please notify us immediately by reply e-mail and delete all records of the message from your computer. The views represented in this message are solely those of the author. Neither the author nor I-D Media AG accepts any liability for the contents of this message.

Joachim Banzhaf

2007-07-19 07:34 UTC #1 lore raw

Hi Falko,

Am Dienstag, 17. Juli 2007 16:33 schrieb Falko Zurell:

Quoted 2 lines

I don't know why this happens. The script will work perfectly 3 out of 5 times. But sometimes it comes up with the error above.

Maybe some hotplug script trying to find out what kind of new device that is?

Quoted 2 lines

Are my steps right in principle? Did I forget to do something before or after removing?

I am by no means an expert on lvm, so dont take this too seriously: shouldn't there be an lvchange -an yourlv before lvremove? Maybe this active status is still hanging around somewhere although you can force the remove?

HTH

Joachim Banzhaf

Falko Zurell

author

2007-07-19 07:48 UTC #2 lore raw

Thanks for the advices. I will look for some hotplug stuff around.

I tried the "lvchange -an" as well as I sounded pragmatic to me. But this doesn't seems to work at all on the snapshots.

thanks and kind regards

---

Falko Zurell
Head of Application Management
Mobil +49 (0)160 - 3 62 52 77

/i-d media AG
Ohlauer Straße 43
D-10999 Berlin

Tel +49 (0)30 - 2 59 47 - 357
Fax +49 (0)30 - 2 59 47 - 471
www.idmedia.com

_______________________________________________

Board: Regine Haschka-Helmer (CEO), Franz Klose (CFO) Chairman of the Supervisory Board: Christian A. Hufnagl
Headquarters: Berlin, Place of Jurisdiction: Berlin HRB 76342 UST-Id. DE812698340
_______________________________________________

This message may contain confidential information and must not be copied, disclosed or used by anybody other than the intended recipient. If you have received this message in error, please notify us immediately by reply e-mail and delete all records of the message from your computer. The views represented in this message are solely those of the author. Neither the author nor I-D Media AG accepts any liability for the contents of this message.

Am 18.07.2007 um 13:37 schrieb Joachim Banzhaf:

Quoted 28 lines

Hi Falko,
Am Dienstag, 17. Juli 2007 16:33 schrieb Falko Zurell:
Quoted 1 line
I don't know why this happens. The script will work perfectly 3
out of 5
Quoted 1 line
times. But sometimes it comes up with the error above.
Maybe some hotplug script trying to find out what kind of new device that is?
Quoted 1 line
Are my steps right in principle? Did I forget to do something
before or
Quoted 1 line
after removing?
I am by no means an expert on lvm, so dont take this too seriously: shouldn't there be an lvchange -an yourlv before lvremove? Maybe this active status is still hanging around somewhere although you can force the remove?
HTH
Joachim Banzhaf
_______________________________________________
linux-lvm mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Stuart D. Gathman

2007-07-19 14:52 UTC #3 lore raw

In reply to Joachim Banzhaf

Quoted 6 lines · Joachim Banzhaf

Quoted 2 lines
Are my steps right in principle? Did I forget to do something before or after removing?
I am by no means an expert on lvm, so dont take this too seriously: shouldn't there be an lvchange -an yourlv before lvremove? Maybe this active status is still hanging around somewhere although you can force the remove?

When I try lvchange -an C4_SNAP, it always fails. So I have had to force the lvremove in the backup script. I am nervous about this, and already asked why this is the case. When reading about the "active" flag, it seems to have something to do with shared SAN storage volume groups, so perhaps we are not supposed to deactivate LVs for simple single machine systems. But the error from lvremove is disconcerting. If I force it, what if there is a *different* error that I really *don't* want to force?

Signature · 4 lines

	      Stuart D. Gathman <[email protected]>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

David Timms

2007-07-19 21:51 UTC #4 lore raw

Quoted 6 lines · Stuart D. Gathman

Quoted 3 lines · Joachim Banzhaf
Quoted 2 lines
Are my steps right in principle? Did I forget to do something before or after removing?
I am by no means an expert on lvm, so dont take this too seriously: shouldn't there be an lvchange -an yourlv before lvremove? Maybe this active status is still hanging around somewhere although you can force the remove?

Quoted 7 lines

When I try lvchange -an C4_SNAP, it always fails. So I have had to force the lvremove in the backup script. I am nervous about this, and already asked why this is the case. When reading about the "active" flag, it seems to have something to do with shared SAN storage volume groups, so perhaps we are not supposed to deactivate LVs for simple single machine systems. But the error from lvremove is disconcerting. If I force it, what if there is a *different* error that I really *don't* want to force?

Perhaps the command produces an errorlevel that you could test against, and only continue when you get the expected error ?

DaveT.

Falko Zurell

author

2007-07-20 06:25 UTC #5 lore raw

Hello,

I got some more debug output from the lvchange command.
I noticed, that sometimes lvchange -an vg0/daily-snap-opt worked and after that I was able to really remove the snapshot.

But most of the times it doesn't work. It seems that system need several minutes do free the snapshot because when I wait some minutes an retry, I can deactivate and remove the snapshot to reuse the name.

root@konrad:~# lvchange -vvv -an vg0/daily-snap-opt
        Processing: lvchange -vvv -an vg0/daily-snap-opt
        O_DIRECT will be used
      Setting global/locking_type to 1
      Setting global/locking_dir to /var/lock/lvm
      File-based locking enabled.
    Using logical volume(s) on command line
      Locking /var/lock/lvm/V_vg0 WB
        /dev/ram0: Not using O_DIRECT
        Opened /dev/ram0 RW
        /dev/ram0: block size is 1024 bytes
      /dev/ram0: No label detected
        Closed /dev/ram0
        Opened /dev/vg0/root RW O_DIRECT
        /dev/vg0/root: block size is 512 bytes
      /dev/vg0/root: No label detected
        Closed /dev/vg0/root
        /dev/ram1: Not using O_DIRECT
        Opened /dev/ram1 RW
        /dev/ram1: block size is 1024 bytes
      /dev/ram1: No label detected
        Closed /dev/ram1
        Opened /dev/cciss/c0d0p1 RW O_DIRECT
        /dev/cciss/c0d0p1: block size is 1024 bytes
      /dev/cciss/c0d0p1: No label detected
        Closed /dev/cciss/c0d0p1
        Opened /dev/mapper/vg0-home-real RW O_DIRECT
        /dev/mapper/vg0-home-real: block size is 4096 bytes
      /dev/mapper/vg0-home-real: No label detected
        Closed /dev/mapper/vg0-home-real
        /dev/ram2: Not using O_DIRECT
        Opened /dev/ram2 RW
        /dev/ram2: block size is 1024 bytes
      /dev/ram2: No label detected
        Closed /dev/ram2
        Opened /dev/cciss/c0d0p2 RW O_DIRECT
        /dev/cciss/c0d0p2: block size is 4096 bytes
      /dev/cciss/c0d0p2: No label detected
        Closed /dev/cciss/c0d0p2
        Opened /dev/vg0/home RW O_DIRECT
        /dev/vg0/home: block size is 512 bytes
      /dev/vg0/home: No label detected
        Closed /dev/vg0/home
        /dev/ram3: Not using O_DIRECT
        Opened /dev/ram3 RW
        /dev/ram3: block size is 1024 bytes
      /dev/ram3: No label detected
        Closed /dev/ram3
        Opened /dev/cciss/c0d0p3 RW O_DIRECT
        /dev/cciss/c0d0p3: block size is 512 bytes
      /dev/cciss/c0d0p3: lvm2 label detected
        lvmcache: /dev/cciss/c0d0p3: now orphaned
        /dev/cciss/c0d0p3: Found metadata at 156160 size 2511 for  
vg0 (Lw0OiY-teNf-jRuy-Ck2s-mqv7-A4BL-8EIzBo)
        lvmcache: /dev/cciss/c0d0p3: now in VG vg0
        lvmcache: /dev/cciss/c0d0p3: setting vg0 VGID to  
Lw0OiYteNfjRuyCk2smqv7A4BL8EIzBo
        lvmcache: /dev/cciss/c0d0p3: VG vg0: Set creation host to  
konrad.
        Opened /dev/vg0/opt RW O_DIRECT
        /dev/vg0/opt: block size is 512 bytes
      /dev/vg0/opt: No label detected
        Closed /dev/vg0/opt
        /dev/ram4: Not using O_DIRECT
        Opened /dev/ram4 RW
        /dev/ram4: block size is 1024 bytes
      /dev/ram4: No label detected
        Closed /dev/ram4
        Opened /dev/vg0/video RW O_DIRECT
        /dev/vg0/video: block size is 512 bytes
      /dev/vg0/video: No label detected
        Closed /dev/vg0/video
        /dev/ram5: Not using O_DIRECT
        Opened /dev/ram5 RW
        /dev/ram5: block size is 1024 bytes
      /dev/ram5: No label detected
        Closed /dev/ram5
        Opened /dev/disk/by-label/opt RW O_DIRECT
        /dev/disk/by-label/opt: block size is 4096 bytes
      /dev/disk/by-label/opt: No label detected
        Closed /dev/disk/by-label/opt
        /dev/ram6: Not using O_DIRECT
        Opened /dev/ram6 RW
        /dev/ram6: block size is 1024 bytes
      /dev/ram6: No label detected
        Closed /dev/ram6
        Opened /dev/mapper/vg0-daily--snap--home-cow RW O_DIRECT
        /dev/mapper/vg0-daily--snap--home-cow: block size is 4096 bytes
      /dev/mapper/vg0-daily--snap--home-cow: No label detected
        Closed /dev/mapper/vg0-daily--snap--home-cow
        /dev/ram7: Not using O_DIRECT
        Opened /dev/ram7 RW
        /dev/ram7: block size is 1024 bytes
      /dev/ram7: No label detected
        Closed /dev/ram7
        Opened /dev/vg0/daily-snap-home RW O_DIRECT
        /dev/vg0/daily-snap-home: block size is 512 bytes
      /dev/vg0/daily-snap-home: No label detected
        Closed /dev/vg0/daily-snap-home
        /dev/ram8: Not using O_DIRECT
        Opened /dev/ram8 RW
        /dev/ram8: block size is 1024 bytes
      /dev/ram8: No label detected
        Closed /dev/ram8
        /dev/ram9: Not using O_DIRECT
        Opened /dev/ram9 RW
        /dev/ram9: block size is 1024 bytes
      /dev/ram9: No label detected
        Closed /dev/ram9
        Opened /dev/vg0/daily-snap-opt RW O_DIRECT
        /dev/vg0/daily-snap-opt: block size is 4096 bytes
      /dev/vg0/daily-snap-opt: No label detected
        Closed /dev/vg0/daily-snap-opt
        /dev/ram10: Not using O_DIRECT
        Opened /dev/ram10 RW
        /dev/ram10: block size is 1024 bytes
      /dev/ram10: No label detected
        Closed /dev/ram10
        /dev/ram11: Not using O_DIRECT
        Opened /dev/ram11 RW
        /dev/ram11: block size is 1024 bytes
      /dev/ram11: No label detected
        Closed /dev/ram11
        /dev/ram12: Not using O_DIRECT
        Opened /dev/ram12 RW
        /dev/ram12: block size is 1024 bytes
      /dev/ram12: No label detected
        Closed /dev/ram12
        /dev/ram13: Not using O_DIRECT
        Opened /dev/ram13 RW
        /dev/ram13: block size is 1024 bytes
      /dev/ram13: No label detected
        Closed /dev/ram13
        /dev/ram14: Not using O_DIRECT
        Opened /dev/ram14 RW
        /dev/ram14: block size is 1024 bytes
      /dev/ram14: No label detected
        Closed /dev/ram14
        /dev/ram15: Not using O_DIRECT
        Opened /dev/ram15 RW
        /dev/ram15: block size is 1024 bytes
      /dev/ram15: No label detected
        Closed /dev/ram15
      /dev/cciss/c0d0p3: lvm2 label detected
        /dev/cciss/c0d0p3: Found metadata at 156160 size 2511 for  
vg0 (Lw0OiY-teNf-jRuy-Ck2s-mqv7-A4BL-8EIzBo)
      /dev/cciss/c0d0p3: lvm2 label detected
        /dev/cciss/c0d0p3: Found metadata at 156160 size 2511 for  
vg0 (Lw0OiY-teNf-jRuy-Ck2s-mqv7-A4BL-8EIzBo)
        Read vg0 metadata (153) from /dev/cciss/c0d0p3 at 156160  
size 2511
        /dev/cciss/c0d0p3 0:      0   2560: root(0:0)
        /dev/cciss/c0d0p3 1:   2560  25600: home(0:0)
        /dev/cciss/c0d0p3 2:  28160  25600: opt(0:0)
        /dev/cciss/c0d0p3 3:  53760 204800: video(0:0)
        /dev/cciss/c0d0p3 4: 258560  87040: NULL(0:0)
        /dev/cciss/c0d0p3 5: 345600   5120: daily-snap-home(0:0)
        /dev/cciss/c0d0p3 6: 350720   5120: daily-snap-opt(0:0)
        /dev/cciss/c0d0p3 7: 355840 119136: NULL(0:0)
  Can't change snapshot logical volume "daily-snap-opt"
      Unlocking /var/lock/lvm/V_vg0
        Closed /dev/cciss/c0d0p3

Unfortunatly these debug messages doesn't give me a clue why the snapshot can't be deactivated.

---

Falko Zurell
Head of Application Management
Mobil +49 (0)160 - 3 62 52 77

/i-d media AG
Ohlauer Straße 43
D-10999 Berlin

Tel +49 (0)30 - 2 59 47 - 357
Fax +49 (0)30 - 2 59 47 - 471
www.idmedia.com

_______________________________________________

Am 19.07.2007 um 23:50 schrieb David Timms:

Quoted 36 lines

Quoted 3 lines · Stuart D. Gathman
Quoted 1 line · Joachim Banzhaf
Quoted 1 line
Are my steps right in principle? Did I forget to do something
before or
Quoted 2 lines
Quoted 2 lines
Quoted 1 line
after removing?
I am by no means an expert on lvm, so dont take this too
seriously: shouldn't
Quoted 1 line
Quoted 1 line
there be an lvchange -an yourlv before lvremove? Maybe this
active status is
Quoted 3 lines
Quoted 1 line
still hanging around somewhere although you can force the remove?
When I try lvchange -an C4_SNAP, it always fails. So I have had
to force
Quoted 1 line
the lvremove in the backup script. I am nervous about this, and
already asked
Quoted 1 line
why this is the case. When reading about the "active" flag, it
seems
Quoted 1 line
to have something to do with shared SAN storage volume groups, so
perhaps we
Quoted 1 line
are not supposed to deactivate LVs for simple single machine
systems. But the
Quoted 1 line
error from lvremove is disconcerting. If I force it, what if
there is
Quoted 1 line
a *different* error that I really *don't* want to force?
Perhaps the command produces an errorlevel that you could test against, and only continue when you get the expected error ?
DaveT.
_______________________________________________
linux-lvm mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/