Recovering Data from a Failed Synology NAS

Concluding Remarks

My Saturday plans went haywire, thanks to the DS414j going belly-up. However, I did end up proving that as long as the disks were functional, it is possible to easily recover data from a Synology RAID-5 volume by connecting the drives to a PC and using UFS Explorer. Users wanting more of a challenge can also use Ubuntu and mdadm for the same purpose. In my case, the data was in a SHR (Synology Hybrid RAID) volume with 1-disk redundancy, but the disks were all of the same size (making it RAID-5 effectively).

Lessons that I learned from my data recovery experience:

• Have access to a PC with multiple spare SATA slots, preferably hot-swap capable
• Back up data written to a NAS frequently (if possible, in real-time)
• Have access to a high capacity DAS (with more free space than the largest NAS volume that you may have to recover)
• Avoid encrypting shared folders and/or volumes, if possible
• Prefer straightforward RAID-x volumes compared to customized (note: customized need not necessarily mean proprietary) RAID implementations and/or automatic RAID level management (such as Synology's SHR / Seagate's SimplyRAID / Netgear X-RAID2)
• In critical environments, run two NAS units in high availability (HA) mode

Things I would like from the NAS vendors' side (Synology already ticks most of these):

• Don't use proprietary RAID / hardware RAID for consumer NAS units
• Instead of (or, in addition to) supplying backup software, provide licensed versions of data recovery software such as UFS Explorer (or, supply one developed internally for Windows / Mac / Linux)
• Provide official documentation for recovering data using PCs in case of NAS hardware failure (using either commercial software such as UFS Explorer or open source ones like TestDisk)

Synology alone is not to blame for this situation. If QNAP's QSync had worked properly, I could have simply tried to reinitialize the NAS instead of going through the data recovery process. That said, for the same purpose, QNAP's QSync worked much better than Synology's Cloud Station (which was the primary reason our configuration utilized a share set up on the DS414j as the target folder location for QNAP's QSync). In any case, I would like to stress that this anecdotal sample point in no way reflects the reliability of Synology's NAS units. I used to run a DS211+ 24x7 without issues for 3 years before retiring it. More recently, our Synology DS1812+ has been running 24x7 for the last one year as a syslog server. The DS414j which failed on me has been in operation for less than two months. I put it down to the 'infant mortality' component in the reliability engineering 'bathtub curve'. Synology provides a 2-year warranty on the DS414j, and any end-users affected by such hardware issues are definitely protected. One just needs to make sure that the data on the NAS is backed up frequently.