Backup via symlink/Samba failing

[MobiusNZ]

Hi there,

We have a server with a large amount of storage dedicated to storing backups, and I'm wanting to store the Zimbra backups directly on it (up till now I have just periodically taken snapshots of the /opt/zimbra/backup dir).

The backup server provides access via Samba, and the zimbra server has the samba share mounted at /sas. I've removed the /opt/zimbra/backup and created a symlink from /opt/zimbra/backup to /sas/zimbra/backup.

The share is mounted as the zimbra user, so there shouldn't be any permission issues there (AFAIK).

However, I'm getting the following error when doing a nightly backup:

com.zimbra.common.service.ServiceException: system failure: Unable to create directory /opt/zimbra/backup/tmp/incr-20100126.120011.272/sys
ExceptionId:btpool0-9638:1264507211276:d2ce09fc2e787c39
Code:service.FAILURE
at com.zimbra.common.service.ServiceException.FAILURE (ServiceException.java:251)
at com.zimbra.cs.service.backup.Backup.handleNetworkR equest(Backup.java:159)
at com.zimbra.cs.service.NetworkDocumentHandler.handl e(Unknown Source)
.....

the zimbra user can create the directory /opt/zimbra/backup/tmp/incr-20100126.120011.272/sys without any problems. Could someone shed some light on this?
Thanks