Been finding some good deals on 2.5 disks lately, but have never bought one before. Have a couple of 3.5 disks on the other hand in my Unraid server. Wondering how much it matters wether I get a 2.5 or not? What form factor do you prefer/usually go for?
Running ZFS on consumer SSDs is absolute no go, you need datacenter-rated ones for power loss protection. Price goes brrrrt €€€€€
I too had an idea for a ssd-only pool, but I scaled it back and only use it for VMs / DBs. Everything else is on spinning rust, 2 disks in mirror with regular snapshots and off-site backup.
Now if you don’t care about your data, you can just spin up whatever you want in a 120€ 2TB ssd. And then cry once it starts failing under average load.
Edit: having no power loss protection with ZFS has an enormous (negative) impact on performance and tanks your IOPS.