Can I use SSDs with ZFS?

[atwillia009]

I have a boatload (i.e. 15x2TB) of SSDs (no HDDs) that I'd like to press into service in building a NAS and I'd like to use Unraid for the OS.  From everything I've read, I know I can't use SSDs with Unraid as data/parity drives using XFS or BTRFS.  Can I use them, however, if I use the Open ZFS plugin?  Is that a "supported" configuration?  Thanks!

[itimpi]

There is nothing stopping you using SSD’s as pools in Unraid in BTRFS or XFS formats.  In fact using SSDs in pools is something most Unraid users do.   It is just that if used in the main array then Trim is not currently supported which means performance can degrade over time.   
 

in terms of using them with the ZFS plugin that should also work fine although at this point ZFS is not officially supported (hence the need for a plugin).   I believe that official support for using ZFS in pools is a roadmap item so official support will arrive at some point.

[gyto6]

You can  use indeed SSD with our without ZFS on Unraid.

When creating the ZFS pool, you must add the parameter

"-o autotrim"

to be certain that ZFS run a "soft" TRIM according to the disk activities. Once per month, you can set the following script with the plugin "User Script" to run an active full disk TRIM :

"zpool trim yourpoolname"

 

Don't know for XFS nor BTRFS commands, but you can run with a script a full TRIM

"fstrim -v /dev/disks/sdx"

 

Edited May 26, 2022 by gyto6

[JSE]

To be clear, if you use a Btrfs pool, Unraid defaults to async discard, so it will TRIM without any configuration needed.

[BVD]

For the first year, I didnt even use the unraid array. It was just 14 disks (eventually grown up to 29), all in zfs. I've been using it since sun released opensolaris way back when, and was just more comfortable with it.

 

Many of us use zfs, and in a myriad of ways.  If you can be a bit more specific about your desired implementation, we can probably answer your questions more explicitly though? If you've never used zfs before, just make sure you fully understand the implications before throwing all your data on it 👍

[atwillia009]

Hi,

 

Thank you all so much for the quick responses!!

 

My use-case/scenario is that I currently have a Threadripper 3970 CPU with 128GB of RAM that I've been using as my daily driver running Windows 11.  I would like to add a NAS to my home network to back up the other computers.  Also, I want to have a place to store/host family pictures and videos without using iCloud or Google Photos (we have both Android and iPhones in the house).  My thought was to take all of the SSDs I've accumulated in the past few years, add them to the workstation and turn it into a multi-purpose server (i.e. NAS, Windows 11 in a VM, and PhotoPrism for photo sharing).  My concern/question is that I only have SSDs and NVME drives and I keep reading that an all-flash storage solution on Unraid would be problematic and not supported.  I don't necessarily want to run ZFS, I just thought that might be a way around what I thought to be a problem.

 

It sounds like y'all are saying that I can use the SSDs/NVME drives with Unraid out of the box and not have any issues (note - in total, I have 15 drives).  If so, does it matter what filesystem I use?

 

Thanks again for the all of the quick help!!!

[atwillia009]

Quick follow-up.  I think I now understand the distinction between the main array and pool (yes, I'm a TOTAL newb).  The cache pool is where I can add all of my SSD's without issue - correct?  I can then move my shares to cache pool.  I believe I can also set the RAID level of the cache pool. 

 

As far as the main array, however, do I still need to come up with one HDD to create the array (even though I won't be using it)?

[BVD]

Your zpool wont be managed within the unraid system/UI - it's not yet a filesystem that's supported for array/cache pools, and will be managed entirely outside of the way you manage your unraid arrays storage (cli)

[itimpi]

57 minutes ago, atwillia009 said:

As far as the main array, however, do I still need to come up with one HDD to create the array (even though I won't be using it)?

You DO have to have at least 1 drive in the main array to keep Unraid happy, but for a Use Case like yours it could be something inconsequential like a flash drive.

 

A point to remember is that you still need to have backups of anything important or irreplaceable.  Having a redundant pool is not enough to guarantee that nothing will go wrong that could cause data loss as there are lots of ways to lose data other than simple drive failure.   Your approach needs to take that into account.

[gyto6]

3 hours ago, itimpi said:

A point to remember is that you still need to have backups of anything important or irreplaceable.  Having a redundant pool is not enough to guarantee that nothing will go wrong that could cause data loss as there are lots of ways to lose data other than simple drive failure.   Your approach needs to take that into account.

 

I confirm. A copy from your data somehere else on another system in your house or online is a backup. You can't bet on any system to take care from your data without any troubleshoot. NEVER

[atwillia009]

Got it!  Thanks everyone for your help!!