Problems with Samba on ESX 3.0.1 while running backup job

[dtnvm]

Hi all.

There is a backup job running on a ESX 3.0.1 which is using a Windows-share as its destination. The backup tool (vi3backup) uses the vcb command line tools to export VMs to disk in this case to a mounted Samba-Share. The Backuptool mounts and umounts this share automatically.

The Backup fails saying:

\[2007-02-18 06:05:04.448 'vcbMounter' 3076460672 error] Error: Failed to export the disk: Input/output error

\[2007-02-18 06:05:04.448 'vcbMounter' 3076460672 error] An error occured, cleaning up...

Here is what I get in /var/log/messages:

Feb 18 06:04:01 vrsesx02 kernel: SMB server not responding

Feb 18 06:04:01 vrsesx02 kernel: smb_get_length: recv error = 5

Feb 18 06:04:01 vrsesx02 kernel: smb_request: result -5, setting invalid

Feb 18 06:04:01 vrsesx02 kernel: smb_writepage_sync: failed write, wsize=4096, result=-5

Feb 18 06:04:01 vrsesx02 kernel: smb_retry: successful, new pid=16314, generation=8

Could this be a bug in the smbfs-module or is it probably a performance problem?

Regards

Kai Hildebrandt

[biekee]

Can you mount the smbfs share manually?

bk

[dtnvm]

Yes.

There are 5 running VMs to backup. Two of the backups failed because of the error described above.

Regards

Kaii

[dtnvm]

Hi.

I got a more detailed error description. This message appearing several times in the logfile:

\[2007-03-10 09:58:59.161 'BaseLibs' 3076460672 warning] DISKLIB-SPARSE: Failed to write out header: Input/output error (327689)

HTH

Kai

[admin]

I've seen this problem running a similar backup script, when you have more than a few hosts exporting to the SMB share simultaneously you get SMB timeout errors. vmkfstools/vcbmounter (which is just a wrapper anyway) bombs out with an Input/Output error at a random point during the VMDK export.

The only fix I have found is to stagger the backups so that no more than two hosts are backing up VMs to a single SMB share at one time. With less hosts backing up simultaneously, I never see this SMB error, so I can only conclude it's a performance related problem that isn't being dealt with very well.

[jappenroth · Accepted solution]

Just to give some feedback:

After installing the CIFS modules provided by Espen Blikstad these problems have stopped. No more input/output errors when exporting VMDKs to the CIFS mounted share.

For information about the CIFS modules see this thread:

http://www.vmware.com/community/thread.jspa?messageID=641717

Many thanks to Espen Blikstad for creating this driver and sharing it with the community!

Regards,

Jan

[admin]

That's good to know, thanks for posting a follow up.