I’m looking to buy my first TrueNAS - likely a Mini R. I was going to make a main pool based off the 5x 12TB drives that I will be moving from my Synology. This will be my working space for photo/videography and other projects (I store 45MP+ RAW files, so space is eaten up quickly). I was thinking of using RAIDz2 for a total of 36TB of storage.
Since the Mini R has more bays than my Synology DS1522+ I was thinking that I could purchase a pair (or three) 4-6TB drives to make a second pool just for Time Machine backups of my work Macbook Pro (w/ 1TB storage) and my daughter’s Macbook (w/ 1TB storage). I know that I could set quotas within the first pool, but it sounds to me like a good idea to separate working data from critical data. If I do 2 drives, I would likely Mirror them. If 3 drives, I’d go for RAIDz2.
Does this sound like a good setup? Is there anything that I’m missing here?
Also, kind of a weird question - but can I leave physical space between the two pool sets in the Mini R? That way I could expand the pool with like drives in the future. For example, have the 12TB drives in the first two “columns” and the smaller drives in the last “column”. Which would leave the third “column” for expansion either direction.
The physical placement of the drives doesn’t really matter. After you create your pools, you can physically move the drives around however you want and it should work without issues. I’ve moved pools/disks to entirely different hosts without issue.
As I mentioned in your other thread, you understand that the existing drives will have to be wiped to use on TrueNAS, right? Just making sure you know you need to have a copy of that data elsewhere before trying to re-use them in TrueNAS. If the second “Time Machine” pool is large enough, you can just use that as the temp storage for your existing data until you configure the old drives in the new pool.
As far as 2-disk mirror vs 3-disk raidz2 – I’d personally opt for a 3-disk mirror over a raidz2 if the capacity is enough. Performance will be better. Rebuilds will likely be much faster. Capacity will be similar.
Yes, thanks. I am backing everything up to external drives in prep for the new system. I will then reload from that when the new array is operational.
Glad to hear that physical location doesn’t matter on the Mini R.
I’m curious to hear that a 3-disk mirror would be better performance vs RAIDz2. Would that matter much in a back up / time machine situation?
OK. I’d personally be very nervous about backing up my irreplaceable data to an external. Hope you’re making more than one copy, just in case.
A raidz pool requires parity calculations. A mirror pool does not. This means higher performance for reading/writing/rebuilding because your CPU is having to do less thinking. For home use with a modern CPU, I’m not sure the performance impact is significant – but it’ll definitely be “not as good.”
WIth that said, i did think of a use-case where I would consider a 3-disk RAIDZ2… If I wanted the flexibility to use the RAIDZ expansion feature to add storage and expected that at some point I will expand to 5 or so disks.
Alternatively, you could later remove one of the disks from the 3-disk mirror (to turn it into a 2-disk mirror), create a new vdev and add a fourth drive to have data striped across two 2-disk mirrors…
Anyway, I’d choose a 3-disk mirror, but you do have options…
Devil’s advocate: for a pool exclusively designated for Time Machine, does it need to resist 2/3 drive failure? Or in the particular context of Time Machine, is it better to have twice the capacity for client backups, using RAIDZ1?
That would be a reason to use separate pools: differing reliability/capacity weights.
