|
|
|
|
|
|
by sillysaurusx
1003 days ago
|
|
|
(Where are you finding friends with a NAS? Or at all, for that matter… guess I’ll look on eBay.) Thank you for the details, particularly about zfs, which I know nothing about. The “if I’m lucky” part piqued my interest. HN was recently taken down by a double disk failure, which is exponentially more likely when you buy drives in bulk - the default case. So being able to survive two failures simultaneously is something I’d like to design for. It’s cool you have two NASes (NASen?) let alone one. They’re the Pokémon of the tech world. |
|
|
If you are concerned about reliability above performance, I would suggest using a single raidz2 vdev instead. This would allow the cluster to definitely survive two disks worth of failure. I'll also echo the common mantra - RAID is not backups. If you really need the data, you need to store a second copy offline in a different place.
When I lived in California and did not have room for a server rack, I had a single home server with an 8-bay tower case. I used an LSI card with 2 SAS-to-4x-SATA ports to connect all 8 drives to the machine. I believe I had 6 TB drives in that NAS, though they are currently all out of my house (part of one of my offsite backups now). My topology there was 4x mirror vdevs, which gave me worst case endurance of 1 failure but best case of 4 failures, and at about 4x the IOPS performance, but with the cost of only 50% storage efficiency vs the 75% you would get with raidz2.
There is even raidz3 if you are very paranoid, which allows up to 3 disks to fail before you lose the vdev. I've never used it. As I understand, the parity calculations get considerably more complicated, although I don't know if that really matters.