I recently had a degraded RAID storage on my NAS. In other words, one of the disks failed and wouldn’t spin up again. Thankfully I am running a RAID1 configuration on two disks, so I only lost one copy of the data. After replacing the disk with a blank new one, the RAID was restored and once again my data is safe and happily redundant on the second disk.
The disk that failed on my was a Seagate NAS HDD 3TB and it lasted 5 years. Funny thing is that the SMART disk monitoring warned me of an imminent disk failure only after the disk had already failed. The NAS (Zyxel NAS542) was angrily beeping after detecting the RAID degradation.
Initially I chose RAID1 for exactly this scenario – when one of the disks fails, I can just buy a new one. No risk of data loss, because it is unlikely that both of the disks would fail at the same time. The second disk is even a different brand (Western Digital Red Plus (EFRX) 3TB), just to make sure. Also, with RAID1 I just need two disks, which is way cheaper than going for the more advanced RAID configurations which need at least 4 disks.
So after the Seagate disk failed, did I go and buy a Western Digital one, since that disk didn’t fail? No. I went for a new 3TB Seagate NAS disk instead. I don’t think there is anything wrong with the brand and I like the benefit of being able to reference the disks by the maker. It helps with identifying them, lowering the chance I accidentally wipe or throw away the wrong one.
In summary: RAID1 is great. Automatic redundancy is important. Keep your data safe!