Last Sunday I woke to find alerts from my Synology DS1511+. The fan in the DX510 expansion unit had failed and one of the drives was reporting as bad. The unit didn’t feel warm but the two were probably related. The drives in the expansion unit are configured as one Synology Hybrid RAID drive (similar to RAID 5) which my Windows Home Server uses an a iSCSI target drive for backups.
I’ve been downsizing local drive storage but at one time my DS1511 had two DX510 expansion bays and that second unit was still there as a ready spare. Being cautious (and lazy) and not selling it off now seems like a good decision.
I did a normal shutdown of the Synology NAS. Then I moved the drives into the spare expansion unit, keeping the drives in the same order. This included the bad drive. To be safe I put the cable into the same expansion port that was used by the bad unit. When I powered up the drives were seen the same as they were in the other unit. The drive was still reported as bad but the logical drive was still accessible by my Windows Home Server. The fan alert was gone too.
I swapped out the drive that showed the error with a spare that I had and began the repair process. With 15TB (5 X 3TB) it took over a day to rebuild but the drive was usable during this time. I assume performance was impacted but the scheduled WHS backup still completed within the usual time frame.
I still need to fix the fan on the now out of warranty expansion unit and do a warranty swap on the hard drive. But it’s nice that the problem was easily solved and took less than 30 minutes out of my weekend.