[linux-lvm] severe problems to remove invalid/full snapshots with debian-etch

[linux-lvm] severe problems to remove invalid/full snapshots with debian-etch

[Tom Assmuth]

hi,

i gave up using lvm2 with debian sarge cause to a lot of problems
concerning stability but now i gave it another try with my debian-etch
box. but here problems with snapshots are still severe.

--
used system:
kernel: 2.6.18-3-686 (normal kernel version in etch)
lvm version
  LVM version:     2.02.07 (2006-07-17)
  Library version: 1.02.08 (2006-07-17)
  Driver version:  4.7.0
--

problem: 

if a snapshot runs full (having attributes like this calling
lvs: Swi-I- ) I of course try to remove it with lvremove:

this will throw something like this on all consoles:

 kernel BUG at mm/slab.c:595!
 invalid opcode: 0000 [#1]
 EIP is at kmem_cache_free+0x29/0x6d
 esi: daa2f28c   edi: d9439a88   ebp: 00036c68   esp: c593fdb0
 Process lvremove (pid: 25402, ti=c593e000 task=c533aaa0 task.ti=c593e000)
 Stack: 15f529ae daa2f28c dd08dc68 dc86c94e dbf84220 00006d8d 00008000 daa2f240
 ...
 EIP: [<c0156f55>] kmem_cache_free+0x29/0x6d SS:ESP 0068:c593fdb0
 ...

afterwards the snapshot is not removed but has the attributes sri---
when it is lvremoved a second time it seems to be away using "lvs"

BUT a new snapshot with the same name fails:
  device-mapper: create ioctl failed: Device or resource busy
  device-mapper: reload ioctl failed: No such device or address
  Failed to suspend origin lvsanyback

lvs gives for this recreated snapshot the attributes -wi-d- 

reboot of the maschine is the only way to help me out.

------

playing around with "dmsetup table" I learned that a snapshot normally
has two entries (the normal name and the name-cow)

when removing the invalid snapshot dmsetup table still shows the -cow
snapshot entry and found no way to get rid of it without reboot.  even
dmsetup remove vgnam-snapshotname-cow only gave a "Device or resource
busy"

Btw reboot mostly did not work. the box has to be resetted and after
start a manual fsck becomes necessary.

---

question: 

Is this a "normal/known" behaviour?? Are there any workarounds besides
reboot?  kernel-issue? Should I try a vanilla kernel and if yes which
one?

---

p.s.:
i have been using lvm1 for many years and I am somehow disappointed
with lvm2 as there are a lot of stability problems and restrictions I
never experienced in lvm1. And lvm1 seems to be not present in debian
etch <sigh>!  (sorry 4 nagging)

-- 
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Re: [linux-lvm] severe problems to remove invalid/full snapshots with debian-etch

[Tomasz Chmielewski]

Tom Assmuth schrieb:
> hi,
> 
> i gave up using lvm2 with debian sarge cause to a lot of problems
> concerning stability but now i gave it another try with my debian-etch
> box. but here problems with snapshots are still severe.
> 
> --
> used system:
> kernel: 2.6.18-3-686 (normal kernel version in etch)
> lvm version
>   LVM version:     2.02.07 (2006-07-17)
>   Library version: 1.02.08 (2006-07-17)
>   Driver version:  4.7.0
> --
> 
> problem: 
> 
> if a snapshot runs full (having attributes like this calling
> lvs: Swi-I- ) I of course try to remove it with lvremove:
> 
> this will throw something like this on all consoles:
> 
>  kernel BUG at mm/slab.c:595!
>  invalid opcode: 0000 [#1]
>  EIP is at kmem_cache_free+0x29/0x6d
>  esi: daa2f28c   edi: d9439a88   ebp: 00036c68   esp: c593fdb0
>  Process lvremove (pid: 25402, ti=c593e000 task=c533aaa0 task.ti=c593e000)
>  Stack: 15f529ae daa2f28c dd08dc68 dc86c94e dbf84220 00006d8d 00008000 daa2f240
>  ...
>  EIP: [<c0156f55>] kmem_cache_free+0x29/0x6d SS:ESP 0068:c593fdb0
>  ...

(...)

Check the answer to my earlier post ("moving logical volumes to another 
system *remotely* - how?") by Bryn M. Reeves:

   This is a known issue in older kernels that was fixed upstream in
   2.6.19. See:

   http://www.uwsg.iu.edu/hypermail/linux/kernel/0612.1/2301.html
   https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=204791


-- 
Tomasz Chmielewski
http://wpkg.org

Re: [linux-lvm] severe problems to remove invalid/full snapshots with debian-etch

[Tom Assmuth]

Hi Tomasz!

On Fri, 02 Mar 2007, Tomasz Chmielewski wrote:

> Tom Assmuth schrieb:
> >hi,
> >
> >i gave up using lvm2 with debian sarge cause to a lot of problems
> >concerning stability but now i gave it another try with my debian-etch
> >box. but here problems with snapshots are still severe.
> >
> >--
> >used system:
> >kernel: 2.6.18-3-686 (normal kernel version in etch)
> >lvm version
> >  LVM version:     2.02.07 (2006-07-17)
> >  Library version: 1.02.08 (2006-07-17)
> >  Driver version:  4.7.0
> >--
> >
> >problem: 
> >
> >if a snapshot runs full (having attributes like this calling
> >lvs: Swi-I- ) I of course try to remove it with lvremove:
> >
> >this will throw something like this on all consoles:
> >
> > kernel BUG at mm/slab.c:595!
> > invalid opcode: 0000 [#1]
> > EIP is at kmem_cache_free+0x29/0x6d
> > esi: daa2f28c   edi: d9439a88   ebp: 00036c68   esp: c593fdb0
> > Process lvremove (pid: 25402, ti=c593e000 task=c533aaa0 task.ti=c593e000)
> > Stack: 15f529ae daa2f28c dd08dc68 dc86c94e dbf84220 00006d8d 00008000 
> > daa2f240
> > ...
> > EIP: [<c0156f55>] kmem_cache_free+0x29/0x6d SS:ESP 0068:c593fdb0
> > ...
> 
> (...)
> 
> Check the answer to my earlier post ("moving logical volumes to another 
> system *remotely* - how?") by Bryn M. Reeves:
> 
>   This is a known issue in older kernels that was fixed upstream in
>   2.6.19. See:

thank you! I have tried 2.6.20 and this works now :-)

> 
>   http://www.uwsg.iu.edu/hypermail/linux/kernel/0612.1/2301.html
>   https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=204791

-- 
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 / _   __   /_/ ( (   /|/| / / /  /_/ 
/ (_) ///  / / __)_) /   |/_/ /  / /