[linux-lvm] RE: Error on unmounting XFS LVM snapshot

[linux-lvm] RE: Error on unmounting XFS LVM snapshot

[Murthy Kambhampaty]

I got these error messages on the Wolk 4.9s kernel, but not on XFS CVS
kernels (or vanilla linux with XFS patches applied). This is a somewhat
random guess, but you might try to upgrade LVM to 1.0.7, following the LVM
how-to, and see if the problem persists.



>-----Original Message-----
>From: Ronny Adsetts [mailto:ronny.adsetts@amazinginternet.com]
>Sent: Friday, October 17, 2003 12:39
>To: linux-xfs@oss.sgi.com; linux-lvm@sistina.com
>Subject: Error on unmounting XFS LVM snapshot
>
>
>Hi,
>
>Please Cc me on any replies.
>
>I am seeing an error logged when unmounting an LVM snapshot of an XFS 
>partition. Google doesn't give me much.
>
>I have reproduced this error on a different system using a totally 
>different disk sub-system (Mylex eXtremeRAID 3000) - the system below 
>has an Adaptec 2400A.
>
>Details are:
>
>System is XFS on top of LVM on top of hardware RAID.
>
>Software used:
>Debian: 3.0 (Mostly)
>Kernel: 2.4.21
>Kernel patches: Debian standard kernel patches; XFS 1.3.0
>LVM utils: 1.0.4-4 (Debian)
>XFS utils: 2.5.6-1 (Debian)
>
>Sequence of actions:
>1: xfs_freeze -f /home
>2: lvcreate -L 1G -s -n home_lv_bak /dev/vg0/home_lv
>3: xfs_freeze -u /home
>4: mount -t xfs -onouuid,ro,usrquota /dev/vg0/home_lv_bak /mnt/home
>5: umount /mnt/home
>6: lvremove -f /dev/vg0/home_lv_bak
>
>On step 5 of above, an error is logged:
>
>Logs:
>Oct 17 17:23:44 jettero kernel: lvm - lvm_map: ll_rw_blk write for 
>readonly LV /dev/vg0/home_lv_bak
>Oct 17 17:23:44 jettero kernel: xfs_force_shutdown(lvm(58,10),0x1) 
>called from line 351 of file xfs_rw.c.  Return address = 0xc01fd6aa
>Oct 17 17:23:44 jettero kernel: Filesystem "lvm(58,10)": I/O Error 
>Detected.  Shutting down filesystem: lvm(58,10)
>Oct 17 17:23:44 jettero kernel: Please umount the filesystem, and 
>rectify the problem(s)
>
>There is no oops and machine seems stable enough, though it's 
>only been 
>running a couple of days since I first did this.
>
>Is this anything to worry about? Is this a known problem? Are 
>there any 
>patches to fix it?
>
>Thanks and regards,
>Ronny Adsetts
>-- 
>Technical Director
>Amazing Internet Ltd, London
>t: +44 20 8607 9535
>f: +44 20 8607 9536
>w: www.amazinginternet.com
>
>

[linux-lvm] Re: Error on unmounting XFS LVM snapshot

[Ronny Adsetts]

Murthy Kambhampaty said the following on 20/10/03 18:10:
 >>-----Original Message-----
 >>From: Ronny Adsetts [mailto:ronny.adsetts@amazinginternet.com]
 >>Sent: Friday, October 17, 2003 12:39
 >>
 >>Software used:
 >>Debian: 3.0 (Mostly)
 >>Kernel: 2.4.21
 >>Kernel patches: Debian standard kernel patches; XFS 1.3.0
 >>LVM utils: 1.0.4-4 (Debian)
 >>XFS utils: 2.5.6-1 (Debian)
 >>
 >>Sequence of actions:
 >>1: xfs_freeze -f /home
 >>2: lvcreate -L 1G -s -n home_lv_bak /dev/vg0/home_lv
 >>3: xfs_freeze -u /home
 >>4: mount -t xfs -onouuid,ro,usrquota /dev/vg0/home_lv_bak /mnt/home
 >>5: umount /mnt/home
 >>6: lvremove -f /dev/vg0/home_lv_bak
 >>
 >>On step 5 of above, an error is logged:
 >>
 >>Logs:
 >>Oct 17 17:23:44 jettero kernel: lvm - lvm_map: ll_rw_blk write for
 >>readonly LV /dev/vg0/home_lv_bak
 >>Oct 17 17:23:44 jettero kernel: xfs_force_shutdown(lvm(58,10),0x1)
 >>called from line 351 of file xfs_rw.c.  Return address = 0xc01fd6aa
 >>Oct 17 17:23:44 jettero kernel: Filesystem "lvm(58,10)": I/O Error
 >>Detected.  Shutting down filesystem: lvm(58,10)
 >>Oct 17 17:23:44 jettero kernel: Please umount the filesystem, and
 >>rectify the problem(s)
 >
> I got these error messages on the Wolk 4.9s kernel, but not on XFS CVS
> kernels (or vanilla linux with XFS patches applied). This is a somewhat
> random guess, but you might try to upgrade LVM to 1.0.7, following the LVM
> how-to, and see if the problem persists.
> 

I've built a later version of LVM 1 tools, but not had a chance to try 
them yet (probably won't bother now).

I did see this this today which appears to be the same issue:

http://www.kerneltraffic.org/kernel-traffic/kt20031027_238.html#4

 From Marcelo Tosatti[1]: "It seems its not safe to create snapshots of 
journalled fs'es without this patch[2]."

Looks like the patch will show up in mainline in the 2.4.24-pre series.

[1] http://marc.theaimsgroup.com/?l=linux-kernel&m=106642797513724&w=2
[2] http://marc.theaimsgroup.com/?l=linux-kernel&m=106623350522639&q=p3

Regards,
Ronny
-- 
Technical Director
Amazing Internet Ltd, London
t: +44 20 8607 9535
f: +44 20 8607 9536
w: www.amazinginternet.com

Re: [linux-lvm] Re: Error on unmounting XFS LVM snapshot

[Greg Freemyer]

> I did see this this today which appears to be the same issue:
> 
> http://www.kerneltraffic.org/kernel-traffic/kt20031027_238.html#4
> 
>  From Marcelo Tosatti[1]: "It seems its not safe to create snapshots of 
> journalled fs'es without this patch[2]."
> 
> Looks like the patch will show up in mainline in the 2.4.24-pre series.
> 
> [1] http://marc.theaimsgroup.com/?l=linux-kernel&m=106642797513724&w=2
> [2] http://marc.theaimsgroup.com/?l=linux-kernel&m=106623350522639&q=p3
> 
> Regards,
> Ronny

Is the above talking about the VFS_LOCK patch, or is there another patch
that should be applied?

Greg
-- 
Greg Freemyer

[linux-lvm] Re: Error on unmounting XFS LVM snapshot

[Ronny Adsetts]

Greg Freemyer said the following on 30/10/03 00:50:

>>I did see this this today which appears to be the same issue:
>>
>>http://www.kerneltraffic.org/kernel-traffic/kt20031027_238.html#4
>>
>> From Marcelo Tosatti[1]: "It seems its not safe to create snapshots of 
>>journalled fs'es without this patch[2]."
>>
>>Looks like the patch will show up in mainline in the 2.4.24-pre series.
>>
>>[1] http://marc.theaimsgroup.com/?l=linux-kernel&m=106642797513724&w=2
>>[2] http://marc.theaimsgroup.com/?l=linux-kernel&m=106623350522639&q=p3
>>
> 
> Is the above talking about the VFS_LOCK patch, or is there another patch
> that should be applied?

It appears to be the VFS lock patch, but I'm no kernel guru...

Regards,
Ronny