Backups failing

I have a series of backups that run at scheduled times during the week. Backups locally have no problems whatsoever. Backups to a NAS unit always fail.

The NAS is on the same internal network and subnet at the server itself (no firewalls or routers)

The server connects to the NAS via FTP and always fails at the same 6 spots during the backup process. Where is fails in each case is during the FTP upload with this error:

    Uploading archive to FTP server ..
    .. upload failed! initial connection failed : Transfer aborted. Data connection closed.

Every step prior to upload reports no error.

The logfile on the NAS shows three attempts to upload the backup each incomplete:

/mnt/md1/backups/server/full/non-media/2010-09-17/ b _ i r server ftp 1 * i

This is a single scheduled backup with multiple domains and so the FTP credentials used to connect are the same from one backup to the next. So why would these routinely fail?

Also, the backups are only TAR with no compression.





Is this backup perhaps too large for the NAS's filesystem or FTP server?

If possible, you should check logs on the NAS to see why it is failing.

That is one of the strange things about it. One backup is approximately 2 GB and always fails. I have others anywhere from 2 GB on up to one that is 12 GB and another that is 70 GB. Those all backup fine.


Anything useful in the NAS logs?

Unfortunately, nothing more than the fact the upload was incomplete - nothing to say how or why.

If you backup the same domains to another FTP server, does it work OK?

Also, can you have the NAS export an NFS or SMB filesystem instead, and have your Virtualmin box mount that?

Can you turn on some kind of debug logging on the NAS? It's quite conceivable that the FTP server there is able to log commands, file access attempts and failures and the like.

You could also turn on error logging for Webmin (in Webmin -> Webmin Configuration) and see if anything useful is logged there.

I refuse to believe that a Linux system, which is SO talkative most of the time, just has nothing to say about those backup upload failures. ;)

LOL, I agree. Ironically the NAS is running a stripped down version of Linux but the FTP server is not configurable and the only logs it has are the transfer logs which only point out the incomplete upload, nothing deeper.

I think I am going to try mounting an NFS volume and see where that gets me.