Hi everyone, I’m very new to the concepts of NAS and servers in general so i apologise for any incorrect terminology in advance
I have an old system that I’ve installed Truenas scale onto sucessfully just using a 250gb SSD for the OS. I’m planning on using the server as a combination NAS drive and also utility server running jellyfin, pihole, mineos etc.
I’m pretty strapped for cash at the moment so I’m only able to expand one drive at a time every few months… I wanted to see whether what i had planned would actually be possible or a huge headache in the future lol. The data stored on these drives are replaceable to semi-important but I have additional backups stored elsewhere so it’s not super sensitive.
My current plan is to purchase a single 4tb ironwolf drive (Drive A) and run it as a basic single hard drive to play around with and get used to setting up docker containers etc. in a few months time i’ll purchase another drive and i’d like to use it as a mirror of Drive A. Is this possible to do when drive A has data on it already?. Later on i’d like to purchase a 3rd drive and switch from a mirror to something like RAIDZ1, would this be possible to do or rather difficult without formatting the drives?
Thanks so much for all your help in advance, I really appreciate it. The community so far have been absolutely fantastic!
Single drive to mirror is possible, but you can’t change from mirror to raidz1 without backing up your data, destroying the existing pool, recreating the pool as raidz1 and then restoring your data from backup.
Thanks so much for your help! So switching from single drive to mirror would be pretty easy? possible to do within the truenas scale GUI?
I figured that would be the case with raidz1, i think that might be the route i take when i eventually expand! can you add more drives to raidz1 after its been created or if i set it up with 3 drives that’s all i get? Many thanks!
Switching to mirror can be done via the truenas gui, yes.
Right now it’s not possible to add single disks to raidz1, but raidz expansion will be available with the next major release of scale in oktober. Before considering adding single disks to an existing raidz1 i’d wait a couple of months before trying it out since it’s a new feature and there may be bugs when it’ll be released.
AFAIK there are already some folks who tried the the nightly builds of the next version to test it and some were successful, others had problems.
That’s fantastic, and great to hear that adding single disks to raidz1 is a feature that’s coming in the near future! What a great bit of software and a great community. Thanks for all your help
Quoting this for emphasis. It’s a feature that’s received a lot of testing in upstream OpenZFS, but it’s also a huge feature in ZFS, and with huge features comes an increased likelihood of bugs. Another trap for young players is that data that’s already on the pool is going to stay at the same data/parity ratio after adding a disk (or two, or three) to the vdev.
Start with one largeish drive that will last you until you can buy another two of the same size.
When you can afford the 2x new drives, it is a bit convoluted, but you can probably convert the existing 1-disk pool into a RAIDZ1 pool as follows: A) create a 3-way RAIDZ1 pool using 2x new drives and a sparse file, then trash the sparse file (equivalent to a disk failing), giving you a degraded RAIDZ1 pool; B) move the contents of the old disk over to the new pool, and then C) destroy the old pool and use the now-spare old disk to replace the “broken” parity drive on the new pool.
This will give you a single redundant pool with two disks worth of space.
You can then incrementally add single drives as needed using RAIDZ1 expansion.
