Why is my Backup server running out of disk space during File Backups?

Although others herein have had similar issues, I have yet to find a solution to this, and not sure what log info is needed to help isolate the issue.

While attempting to run a File Backup… The process slows down to a crawl and notice my backup server received the dreaded ‘running out of disk space’ warning. The only means of stopping this task then is by restarting the URB Service. Clicking the ‘Stop’ button under ‘Activities’ does not seem to do anything, and I’ve let it sit there for 20 mins after clicking it.

I’m not understanding how URB does file backups, but it must be different than Acronis and EASEUS Todo Backup. Acronis/Todo Backup has never given me such warnings on file backups and takes the same amount of time for roughly the same amount of data backed up as imaging.

  • Imaging backups are successful and execution time seems appropriate
  • My host backup server has 35 GB of free disk space available
  • The backup is of a Client drive
  • Host: Win 11 Pro, sufficient resources
  • Client: Win 11 Pro, sufficient resources



Based on what is in the image/s, it looks like the backup is going to the C: drive of the host…rather than the D: for the backups…

Would need to see more about the config to understand why, but am guessing that the default database/store is still writing to somewhere on the OS drive itself…

You can probably use TreeSize or similar to confirm [when a backup is running and you’re seeing this] which folder/s are taking the consumed space, though you might be best to give it a run when the space is fine to be a fair comparison…

Thanks, though at least my C drive is not the ultimate saved place. I don’t see any obvious backup file creation, and I see the below in the running log…

05/24/24 22:01  	DEBUG  	HT: Copying file to "E:\IMAGES\URB\PC1[DATA]\240524-2159\D\$RECYCLE.BIN\S-1-5-21-2855923542-1875307789-2507340055-1001\$IFA1PFV.xml"

Best guess is it’s caching all data before actually copying it over? It’s really strange.

Edit: Using TreeSize, I found the following path growing w/ temp files. So is the above the case… URB creating temp files before actually copying them to the backup destination?



Can only give you a few pointers, as my UrBackup server instances have all been on Linux rather than Windows hosts…but…

Am guessing you have set the repository to the data drive on here…?

There is also a box on Settings > General > Advanced about using temporary buffers for file and/or image backups; mine are [both] unticked so might be something worth checking for your environment…?

Thanks for the input. Although disabling the temp files in the Settings > Advanced section seemed like a good solution, that did not do the trick.

Just looked at your post again, and am wondering if you meant to include the Recycle Bin folder/s in the backups…? For me, it’s a waste of backup storage to keep that/them backed up - especially as it’s easy to filter out…

This is what I have for my Windows client backup exclusions:

$Recycle.Bin;AppData;WinSxS;*.ost;System Volume Information;Windows/CSC;Windows/Installer;

Let me have more of a look at the web GUI to see if there’s anything there, but I have a feeling that the answer may be hiding in a config file…

How much free disk space do you have on your C: drive before the backup begins? What’s the total size of the files you are backing up? What’s the size of the largest of these files?

Thanks, I had not filtered those out. I have since cleared it and there wasn’t much in there.

Thanks for the reply… I believe I mentioned there was 35 GB free space. I’ll get the numbers when I can. Not sure what that would answer though as I can do a backup of the same files using EASEUS and it completes successfully, as expected. There must be either a config setting or to understand how URB differs in it’s process.

You said the backup is of a client drive and the host server has 35GB free. I am asking about client. Urbackup is a client/server backup program unlike Easeus, so identifying the client and server is important.

Based on the screenshots above, it looks like the server has a 106 GB drive for the OS which runs out, and 732 GB free on the 2.7 TB backup storage drive…

Looking at the raw data from the backup that was running, it’s showing 340 GB of source data…

Well apparently 98Gb as transferred which seems unlikely if everything is going to the C: drive because it may only have 35Gb free. OTOH if there is a 35Gb file sitting on the client then perhaps that might cause it. But it is guesswork because there is not enough info.

Thanks all for the input, though I think I’m going back to strictly imaging. I truly don’t need constant, incremental data backups.