DS1512+: RAID5+spare or SHR

[epatric]

Hi,

Just got a DS1512+ loaded with 5 x 3TB disks. My initial thought was to go for RAID5 + spare but after reading a bit I'm now not sure whether SHR with 2-disk redundancy is the way to go. Haven't done RAID6 before, maybe an option as well.

My highest priority is to have zero data loss, of course because I value my data but also because I won't be able to physically access the NAS myself. I need it to be plain simple for my hands-on guy if something goes wrong, i.e. please change disk 4.

I'd appreciate any input/advice on which way to go...

[HarryPotter]

Raid6 and SHR2 is the same as long as all disks are of same size.

RAID is no backup solution at all. If your priority is no data loss, make external backups.

[epatric]

HarryPotter,

Thanks for reply. Let's say my goal is zero data loss (everyone wants it, right?), however the added redundancy compared to what I had before is a huge difference. I have external backup connected as well.

From what I understand so far, the big advantage of SHR is that I can upgrade the array with bigger disks without formatting the whole thing (if hdd size is supported by DSM that is)?

[myCloud]

Standard RAID 6 -- an array can be a backup ( 2nd or more copy ) to primary data elsewhere. If it is the primary data location, the data on it needs to exist elsewhere. Due to fire, theft, etc, a backup isn't a backup unless it is off-site.

[maxxfi]

For a 5 disks array, probably RAID6 (or the equivalent SHR/2) is a bit excessive as anyway (as already commented) RAID is not there to provide safety of data.
However, if you plan to add many more disks to the 1512+ *and* they will be added to the same volume, it may be good idea to start right away with a double-parity system and go RAID 6.
Regarding whether to use plain RAID or SHR, as you are looking for easy maintenance system probably you should go for SHR, as it gives you also more flexibility than plain RAID in case you'll use drives of different sizes, and there is no real 'penalty' compared normal RAID.