Can ZFS Drives Be Part of Array?

[HarryMuscle]

I've read that there are two ways that ZFS can be supported in Unraid, one is via the ZFS plugin which specifically mentions that ZFS formatted drives cannot be part of the array, and the second is apparently via native ZFS support in the kernel itself that Unraid uses.  If adding a ZFS drive via the second route, can it be part of the array (I assume if it can it will most likely be done via the command line which is perfectly fine)?  Also, any guides on how to add a ZFS formatted drive that is natively supported by the kernel?  All the guides I'm finding are related to the plug-in cause that was the initial way of adding ZFS to Unraid.

 

Thanks,

Harry

 

P.S. When referring to ZFS drives, I'm referring to individual ZFS formatted drives, not a ZFS pool made of multiple drives with its own redundancy, etc.

 

 

 

Edited November 5, 2021 by HarryMuscle

[JorgeB]

5 hours ago, HarryMuscle said:

can it be part of the array

Not for now, likely it will be possible in the future.

[HarryMuscle]

On 11/5/2021 at 3:55 AM, JorgeB said:

Not for now, likely it will be possible in the future.

What would happen if a person formatted a drive that is part of the array as ZFS via the command line?  Would it be removed from the array or cause an error or would it stay in the array?

 

Thanks,

Harry

[trurl]

The only way to get a disk out of the array is to replace it or rebuild parity without it. An array disk formatted as ZFS I expect would be considered Unmountable.

[ich777]

43 minutes ago, HarryMuscle said:

What would happen if a person formatted a drive that is part of the array as ZFS via the command line?

Why would you do that?

Try it andy you will se what happens... If nothing happens, the next reboot will be funny... 

 

Jokes asside, no that is not possible currently, you also will have no benefit if you format it in ZFS, or what do you think would be the benefit? ZFS won't be quicker than with XFS because the Parity data is always calculated. It will always prompt you that one disk is not formated in the right filesystem.

 

Why don't you create a zpool outside from the array/cache like most people do it including myself. I have one drive as a cache installed and the zpool holds my Docker path (I'm not using a image), my appdata folder, libvirt.img and so on and it works really nice on RC2.

 

[HarryMuscle]

6 hours ago, ich777 said:

Why would you do that?

Try it andy you will se what happens... If nothing happens, the next reboot will be funny... 

 

Jokes asside, no that is not possible currently, you also will have no benefit if you format it in ZFS, or what do you think would be the benefit? ZFS won't be quicker than with XFS because the Parity data is always calculated. It will always prompt you that one disk is not formated in the right filesystem.

 

Why don't you create a zpool outside from the array/cache like most people do it including myself. I have one drive as a cache installed and the zpool holds my Docker path (I'm not using a image), my appdata folder, libvirt.img and so on and it works really nice on RC2.

 

My ideal setup would be using ZFS (for it's checksumming ability, snapshots, etc. and most importantly greater maturity than BTRFS) as individual disks (ie: pools of one disk each) all part of the Unraid array so that they are protected against disk failure.  Which is why I'm trying to understand the technical side of things as to why they can't be part of the array.  Obviously this isn't supported via the GUI, but as far as I understand it the parity created on the party drive(s) is file system agnostic.  Now if the GUI is designed to complain if it doesn't recognize the file system of a disk (even though the kernel supports it) then I could understand that being an annoyance or even a deal breaker depending on what the GUI prevents from working under such a situation.

 

 

[Squid]

2 hours ago, HarryMuscle said:

even though the kernel supports it

The linux kernel does not natively support ZFS due to licensing issues.

[HarryMuscle]

11 minutes ago, Squid said:

The linux kernel does not natively support ZFS due to licensing issues.

Bad choice of words on my part ... I mean the kernel supports it because there's a module loaded into the kernel either manually or via the ZFS plugin.  End result is the same though.

Edited November 7, 2021 by HarryMuscle

[JorgeB]

Unraid is expect to support ZFS as of next release (v6.11), for now would get an unmountable disk if you tried to use ZFS in the array.

[ZataH]

On 11/7/2021 at 10:48 AM, JorgeB said:

Unraid is expect to support ZFS as of next release (v6.11), for now would get an unmountable disk if you tried to use ZFS in the array.

Do you know when 6.11 is expected to go into RC ?

[ChatNoir]

1 hour ago, ZataH said:

Do you know when 6.11 is expected to go into RC ?

Probably not before several months. 6.10 is not stable yet.