Not long ago I installed some SSD cache in a Synology DS1815+. It was a cinch.
To my surprise, less than 1 week into it’s life, one of the mirrored Samsung 850 Pro drives failed. Fortunately this unit was not in production, but it would not have mattered as the cache remains online with a single failure in a RAID 1 pair. The drive was replaced as DOA from our vendor and the process to replace it began. As expected, and as it should be, this was a painless and quick task.
First of all, replace the disk and ensure it shows up in the Storage Manager. From the SSD Cache page, choose “Repair”
The new disk will be offered, tick it and “Apply” Accept the warning. My initial thoughts were that this warning may be suggesting the existign cache contents will be lost, but more on that later. Click OK and wait a moment.
The Repair process begins and progresses quickly.
At 100%, the “Used” figure returns to the initial size, meaning that the Cache is preserved…Cool !