Beware of data corruption on old Synology DSM versions

from Star Trek: Nemesis, © Paramount Pictures

Just a quick hint when you experience corrupted data on your Synology NAS: make sure to use the newest DSM version available.

By „corrupt data“, I mean one or more of the following (rather easy to spot on image files):

I just noticed this on my Lightroom archive (which sits on my NAS), and I could reproduce it consistently when copying a directory with about two hundred JPGs from my Mac to a network share on the NAS using either AFP or SMB – some of the files just appeared with a size of 0 bytes. Also, when importing images into my Lightroom archive (which is done via NFS), the import got stuck halfway and only showed about a third of the images imported.

I first suspected my recent upgrade to OS X Mavericks (10.9), but a fresh install with Snow Leopard (10.8) showed exactly the same. My wife’s Macbook Pro (also on 10.8) didn’t do any better, whereas my Windows 7 box had no trouble at all (and was almost twice as fast, but that’s another story).

It turned out that my Synology was still running DSM 4.3-3211, and an upgrade to the newest version (4.3-3827) did in fact fix the issue. So, three things to learn here:

  1. Check the integrity of your file archives regardless of where they are stored (external disk, NAS, cloud backup, …)
  2. Do. Regular. Backups. (But make sure not to overwrite perfectly fine backups with broken data…)
  3. Do. Regular. Updates.



Thank you!! We were having the same issues – thanks for your advice.

Posted by cassie on 5 August 2014 @ 10pm

Hi there,
I’m using DSM5.0-4493 and I have the exact issue you describe (getting zero bytes files when copying or, much worse, when moving). Do you know what else could be wrong?

This post is the only one I found which says something similar to what I’m experiencing, so…


Posted by Bob on 22 August 2014 @ 9pm

this seems like a synology problem. I have had various Disk Stations since 2010, and it seems that only jpgs on the DS are corrupted, and not on other media sources. What a major disappointment with this brand…

Posted by Ivan on 22 September 2014 @ 8am

For what it’s worth, I’ve not experienced the issue since upgrading – but I agree, this should have been caught in testing.

Posted by ennonymous on 2 Februar 2015 @ 7am

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