Recovering Data from a Failed Synology NAS
by Ganesh T S on August 22, 2014 6:00 AM ESTConcluding 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.
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Lerianis - Friday, September 5, 2014 - link
Links to the articles supporting that please.YoshoMasaki - Monday, August 25, 2014 - link
Hi there, I was wondering if you would recommend "Windows Server 2012 R2 Essentials with Update x64" as a home server for backups? I can get this for free through Dreamspark (https://www.dreamspark.com/Product/Product.aspx?pr... but I have never used WHS before and I'm a little intimidated by it. Reading "Windows Server 2012 R2 Essentials ... continues to have the requirement that it must be an Active Directory domain controller and that it must be the root of the forest and domain" (Source here: http://winsupersite.com/windows-server-2012/window... makes me think I'm in over my head, but I REALLY get lost when folks here talk Linux/Unix file systems and custom RAID stuff with a half-dozen drives. I'm a Windows guy for 20+ years now so I think I can learn it but I wonder if it'd be worth it. Thanks for your input.YoshoMasaki - Monday, August 25, 2014 - link
Post above ate my links ... please remove the parenthesis from the end or click here:https://www.dreamspark.com/Product/Product.aspx?pr...
http://winsupersite.com/windows-server-2012/window...
fatbong - Monday, August 25, 2014 - link
Completely agree. I wish there was a NAS available which used NTFS and simple disk mirroring. It would make data recovery extremely easy, if the NAS were to suffer hardware failure. I have an aging Buffalo Linkstation Quad, and hardware failure worries me. Is there any NAS out there which uses NTFS ? And no, I dont want to build/buy a server. I want an appliance.Stylex - Thursday, August 28, 2014 - link
Yeah, I migrated from WHS 2003 to Win8 with DriveBender, similar to Drivepool. Love that if it goes sideways all my stuff is NTFS. I don't have time or stress levels to deal with linux command line stuff to get it working again.BD2003 - Friday, August 22, 2014 - link
I recently decided to drop my home NAS (synology ds212j), since I no longer have multiple PCs...and getting that data off was a nightmare. It had a backup drive that was formatted in ext4, since synology didn't support incremental backups to NTFS.Because of the way it stored the incremental backup, it was basically useless for reading directly through an ext driver for windows. I had to completely wipe the backup drive and reformat it in NTFS to make a one time backup, and cross my fingers that I didn't lose a drive during the damn near 24 hour process (thanks to the hyper fragmented NAS drives, barely adequate NAS CPU and USB 2.0.) Then I had to pull the drives, reformat them, and pray the backup worked. Then transfer everything back. This process literally took days.
If it was a windows based box, I could have just pulled the drives, dropped them in the PC and been done with it in 5 minutes, without even rebooting. I probably would have never even dropped the NAS, since I could upgrade it without having to migrate anything.
Basically the entire experience put me off of ever using a Linux based NAS ever again. Between the file system incompatibility and the potential for RAID array failure....it's just not worth it. My data has never felt so unsafe than during that process.
dabotsonline - Friday, August 22, 2014 - link
"In the end, I decided to go with a portable installed system, which, unlike a persistent install, can be upgraded / updated without issues. I used a Corsair Voyager GT USB 3.0 128 GB thumb drive to create a 'Ubuntu-to-go' portable installation in which I installed mdadm and lvm2 manually."Even though it wasn't specified in the Synology FAQ, wouldn't a portable installation of Parted Magic or SystemRescueCd work OK?
Christobevii3 - Friday, August 22, 2014 - link
From my experience with my synology 413j for a while I've learned a few things:First: Turn on the smart disk check to run weekly, otherwise if you never restart the device you won't have a hint of failure coming.
Second: 5TB usb's are cheap, setup a backup task to these.
Third: UPS. Always run a ups. A $50 apc is enough and will hold the device up for a while and allow it to shutdown properly in a power outage.
Last: If you have a disk failure it locks up the device. You will probably be able to detect which disk it is by pulling one at a time. When you get the proper one it will be accessible and you know which disk to replace.
jbm - Friday, August 22, 2014 - link
Very interesting article - have often asked myself what to do if my NAS ever should die a sudden death, because it's a bit old (Thecus 4200) and I probably would neither manage to buy another one nor want to (not because it is bad, just because I'd rather switch to something newer). More articles like this, please!Nogami - Saturday, August 23, 2014 - link
I'd be curious what exactly was the component that died - I've had yet another capacitor failure in the last week which took out an old LGA 775 motherboard (though it happily enabled an upgrade to an i7-4790K).All in all, the vast majority of hardware failures I've had in the last 5 years has been due to capacitor death, usually in power supplies, causing general flakyness, and eventually becoming terminal. I'm curious if that was the case here as well.