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vzdump with LVM snapshot: strange input/output error [message #39629]

Sat, 22 May 2010 08:16

Master One
Messages: 9
Registered: October 2007

Junior Member

I am getting a strange error when running vzdump, although everything seems to be working just fine and the dump is done correctly:

# vzdump --compress --snapshot --all
INFO: Starting new backup job - vzdump --compress --snapshot --all
INFO: Starting Backup of VM 1010 (openvz)
INFO: status = CTID 1010 exist mounted running
INFO: creating lvm snapshot of /dev/mapper/vg1-vz ('/dev/vg1/vzsnap')
INFO:   /dev/dm-10: read failed after 0 of 4096 at 0: Input/output error
INFO:   Logical volume "vzsnap" created
INFO: mounting lvm snapshot
INFO: creating archive '/var/lib/vz/dump/vzdump-1010.dat' (/mnt/vzsnap/1010)
INFO: Total bytes written: 573726720 (548MiB, 5.4MiB/s)
INFO: file size 224MB
INFO:   /dev/dm-10: read failed after 0 of 4096 at 0: Input/output error
INFO:   Logical volume "vzsnap" successfully removed
INFO: Finished Backup of VM 1010 (00:02:02)

I have no idea, what the problem could be, there is enough space left in the VG for creating the snapshot LV.

Any idea?

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Re: vzdump with LVM snapshot: strange input/output error [message #39655 is a reply to message #39629]

Sun, 23 May 2010 03:22

sHaggY_caT
Messages: 144
Registered: August 2008
Location: Moscow, Russian Federatio...

Senior Member

1. your snapshot has'nt free size: files in backup'ing containers on disk subsystem (HDD, raid, ...) is changed

OR

2. Your HDD(s)/raid is bad, and need to replace

IT-outsource for UNIX servers,
http://ha-systems.ru

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Re: vzdump with LVM snapshot: strange input/output error [message #39657 is a reply to message #39655]

Sun, 23 May 2010 07:29

Master One
Messages: 9
Registered: October 2007

Junior Member

(1) There is enough space left for the snapshot LV, as well as for the actual backup in /vz/dump

(2) It's a hardware RAID-10, and there is no problem with it.

Still no clue, what the shown error message is trying to tell, because as you can see, the "vzsnap" volume is created after all, and the backup is done.

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Re: vzdump with LVM snapshot: strange input/output error [message #39658 is a reply to message #39657]

Sun, 23 May 2010 07:37

sHaggY_caT
Messages: 144
Registered: August 2008
Location: Moscow, Russian Federatio...

Senior Member

I think, you have _old_ snapshot. This snapshot destroyed, becouse your file system is changed, but old snapshot has small size.

use ls -l /dev/mapper/, lvs, lvremove -f, to delete old snaphot.

Are you shure of self-status of raid's disks/raid status?
May be, it's was be degraded in some days, and now has new failure?

But i think, it's old lv snapshot

IT-outsource for UNIX servers,
http://ha-systems.ru

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Re: vzdump with LVM snapshot: strange input/output error [message #39699 is a reply to message #39629]

Tue, 25 May 2010 07:57

Master One
Messages: 9
Registered: October 2007

Junior Member

There was no old snapshot LV in /dev/mapper/ to remove, and the RAID is definitely OK and has been all the time (hardware RAID-10 in an IBM eServer xSeries 226, each SCSI HDD has a LED to light up in case of an error).

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Re: vzdump with LVM snapshot: strange input/output error [message #39701 is a reply to message #39699]

Tue, 25 May 2010 08:38

sHaggY_caT
Messages: 144
Registered: August 2008
Location: Moscow, Russian Federatio...

Senior Member

Please run and copy/paste output of commands:

ls -l /dev/dm-10
ls -l /dev/mapper/

I think, it's old snapshot without free size, and you wrong...

IT-outsource for UNIX servers,
http://ha-systems.ru

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Re: vzdump with LVM snapshot: strange input/output error [message #39702 is a reply to message #39629]

Tue, 25 May 2010 08:53

Master One
Messages: 9
Registered: October 2007

Junior Member

Ok, that one solved the mystery:

/dev/dm-10 is a luks-encrypted disk, which has been shut off due to power-supply failure, and since that one was not hot-swap, it still shows up a active block device.

Didn't think of that, because that disk was not used for anything, and which is why I have no clue, why vzdump tries to access that drive.

Thanks, sHaggY_caT. Smile