We unfortunately suffered a hard disk failure over the weekend, which meant that a replacement was required. We had been watching the ’Reallocated sector count’ rising on the specific disk for some time and it was in range of 2000 so were not totally surprised by the turn of events. One can run with a small number of reallocated sectors as the bad sectors will have been replaced with spares. Their Logical Block Addresses (LBA) having been reallocated to other physical sectors. It is only when the number of spare physical sectors run out that one runs into real problems. We also note that a couple of the other drives have a few reallocated sectors but these are in the low numbers and are not increasing so there is no need for concern at the moment.
Fortunately the disk was part of a RAID 6 configuration which meant that no data was lost and we could run in a degraded mode until such time as we could replace the disk. We could even have survived a further failure, but fortunately that was not necessary.
The disk duly arrive and we plugged it in and restarted our QNAP system. The drive was accepted and a RAID rebuilt immediately started. It was as simple as that. No reconfiguration of need to do anything at all, just wait for the rebuilt to complete. Simplicity itself.
This all helps justify our original decision, several years ago to purchase a QNAP system, and this is the first drive that we have had to replace, so it has paid for itself over the years.
In that time the drive technology has moved on, and our replacement drive, a Seagate Constellation ES, whilst not being identical to the original, it being a later and ‘faster’ model, was a perfect match, and we note runs slightly cooler.