The original post: /r/datahoarder by /u/hefas on 2025-01-25 20:26:55.
I'm currently using a vm with TrueNAS as my NAS for media and important things. I really don't like it. It's too complicated and too powerful for what I need and I'm constantly afraid that I'm one bad uninformed decision away from losing my data. So I decided to move at least my important files to a thing I would feel more confident using and less likely to brick thus I bought unas pro. Also this will allow me to have a backup on a separate machine - the TrueNAS I'm currently using.
I have one 16tb hdd that I use for media and two 4tb HDDs that are mirrored for my important things that are also backed to the 16tb drive.
I can't decide which drives to move to unas as it can only have 1 pool.
At first I considered buying 4tb drives (to have 4 in total for when raid6 is available and adding more when needed) but price per tb compared to 16tb drives is way bigger. Also more drives=more watts which do add up over the years (about 8eur/drive a year for me).
Another consideration is buying an extra 16tb drive and have them mirrored on unas and use the 2x4tb drives on TrueNAS to backup the important stuff. With this UNAS would store important files+media and truenas only backups. My issue with this is I don't need my media on a raid so this would waste my storage (and maybe accelerate the degradation of HDDs and increase failure rate?)
I'm looking at buying 16tb Ironwolf pro for 264eur(16eur/tb) as it's the same as I already have or 4x4tb Iron wolf pro at 86eur(21eur/tb). I think I can't reuse my old 4tb HDDs because they're WD REDs(very likely SMR) so I would have to buy all 4 new (86x4=344eur). Innitial cost is bigger with smaller drives but its more safer? And failures would be less costly. My important data is currently about 3tb so I'm not too concerned about running out of hdd bays.
If your important data is 3TB (and not expected to grow quickly) I would probably just keep one copy on the TrueNAS RAID and then get an external drive to make a second copy as a backup.
I think I'm in a similar situation as you except I'm building the entire system from scratch. I decided to go with 6x8TB drives in RAIDZ2 for the trueNAS system then I'll get a larger single drive (14-24TB range) to make regular backups of just the most important data. This will be my first time using TrueNAS so I'm not an expert or anything but I've read that one advantage of smaller drives is that rebuilds can go smoother after a failure and there is less chance that a second drive fails during the rebuild. In my case I technically could have gone with something like a pair of 24TB drives mirrored instead of the 6 disk RAIDZ2 but I don't think the mirror would allow "scrubbing" to repair corrupted data using the parity bits. This probably doesn't directly answer your question but I hope it helps.