exFAT External Drives Unreliable For Backups?

[SpaceCoyote]

Hello,

I recently started using Veeam Agent because I needed to send my laptop in for repair where it underwent a factory reset and I want to start running full-system back-ups on a regular basis. When I got the laptop back today, I booted from my recovery USB and started a bare-metal recovery but I discovered that 2 out of 3 of my full backups failed early in the process and gave me a long error message that included the text Failed to decompress LZ4 block. Fortunately, my oldest backup was able to complete the recovery. After doing some research online, I'm still not sure what caused these errors, other than the possibility of corrupted data (https://www.veeam.com/kb1795), but I did see some brief mentions about exFAT file formatting not being the most reliable for backups - is this true?

I saved my backups to two separate 1TB M.2 SSDs that I placed in external USB enclosures and formated them both as exFAT (I got into the habit of formatting my external drives in exFAT because I used to work with both PCs and Macs). One full backup failed on each drive.

It would be good to know if the file format of my drives is the culprit otherwise I'm not feeling so confident in Veeam as a reliable backup solution.

Any input is greatly appreciated!

[HannesK]

Hello,
and welcome to the forums.

but I did see some brief mentions about exFAT file formatting not being the most reliable for backups

where did you see that?

The "Failed to decompress LZ4 block" is normal for broken media. It sounds strange to me, that you have that for two different SSDs. Maybe a broken USB controller? I mean, broken raid controllers are one of the most popular reasons for data loss, so maybe it's something similar.

You could enable health check for more detailed tests. I don't believe that it has something to do with the file-system.

Best regards,
Hannes

[SpaceCoyote]

Thanks for your reply, Hannes! It was on various forums, people mentioning they choose NTFS/HFS over exFAT because of reliability; no concrete information and mostly anecdotes and opinions. But I thought it might be worth investigating further.

I believe the health check is enabled by default? I haven't been using Veeam long so maybe one of these checks hasn't been performed yet. I'll make sure it's on a consistent schedule. (EDIT: Looks like I don't have the health check and Backup Repository options when I choose the Destination as Local Storage)

You mention a broken USB controller - both of the M.2 enclosures I'm using are quite cheap no-name models that I bought from eBay. Maybe they could be causing problems?

[HannesK]

Hello,
no, health check is never enabled per default. It's because it would be a performance problem for many customers that are running on spinning disks.

"could" - everything "could" be the issue. Even two broken SSDs The problem is, that it is time consuming to debug. If you can easily change to NTFS, then I would give it a try.

Best regards,
Hannes

[SpaceCoyote]

I found the option for health check and I enabled one day a week for a checkup.

Yeah, it now sounds like a number of things could corrupt a backup. It's not a big deal for me to reformat to NTFS so I'll do that and hope for the best!