Hello! I've recently aquired an old PC which is going to replace my Raspberry Pi 4 as a home server and I'm new to unRAID. This PC has 2x 256GB SATA SSDs in it, which I'm planning to use for the cache pool (that will also store docker appdata).

I know traditional wisdom would dictate that I set this up as a RAID 1 style mirror, but I am a bit cocerned that 256GB will not really be enough capacity, especially if I want to spin up a Windows VM.

Given that as I understand it Mover can be configured to transfer the cache files to a parity protected array daily, and that I can use another solution like this plugin for daily appdata backups, is it really that much of a risk? I suppose even if I avoid data loss, it would still result in downtime if an SSD failed without warning. I'm curious what people's opinions are on this, and want to make sure I haven't missed a risk factor with this setup.

Thanks in advance :)

Well the risk is losing a single drive means total loss of the pool and most people, including myself, prefer our systems remain running and functioning in the event of a drive loss.

256GB is what I consider on the low end but I dont see why it wont be usable. I ran unraid for years with only a 250GB single drive pool before switching to a RAID10 setup where I now run mirrored pairs for my pool.

As long as you have a good backup strategy, which you should have regardless of your pool configuration, and are prepared to deal with it shall a failure occur, it's your system to do as you wish with.

Thanks, thinking about it I suppose I can always reformat as a stripe later if I desperately need more space - for now I'll configure as a mirror.