Basic ReadyTIER Questions

nsne

• Although the ReadyTIER guidelines say the number of SSDs should (not "must") match the number of HDDs, is it possible for me to use 2x SSDs to tier a 4x HDD array?

Yes, the minimum number of SSDs to start a tier for RAID levels 1 and up would be two. You will be able to get the Add tier button after selecting the two SSDs you have.

• If so, are there serious (or any) risks in the 2x SSD/4x HDD setup as opposed to an equal 3x setup?

There shouldn't be any issue or risk on using 2x SSD on your setup but it is always recommended to expand your tier to avoid metadata falling back writing on the mechanical drives. This is if you are using most of your metadata allocated space

• Is a ReadyTIER setup any more prone to irrecoverable data loss than a standard configuration?

a ReadyTIER is a RAID group as well, using 2x SSD means you have a RAID1 tier, so you have a 1 disk mirrored. Adding more SSDs for your tier will also change the RAID level.

• Are there any other ReadyTIER caveats that I might be overlooking?

Members using the Tier feature would be able to suggest more :)

And for the forum folks who love to wag their fingers, yes, the 626 is being backed up daily (to the old 314). But I see restoring data from a backup as a last resort. I don't want to lose the primary data in the first place.

It is always recommended to do backup from several devices or locations so to make sure that data is not lost in the event that we are not expecting to :) using a NAS does not secure data at all times.

HTH

Regards