Importing zpool from special OpenZFS

[beardmann]

Hi there,
I am trying to find out if it is possible to import my existing ZFS pool into TrueNAS.
I currently run my Ubuntu 20.04.3 as a virtual VM on ESXi, where I have presented a hardware SAS HBA card (LSI SAS3008) to the VM.
I have also added some virtual NVME disks for cache.
Right now I am running a raidz3 with 24 disks which are installed in a NetApp DS4246 shelf.
I then have a read cache consisting of just one NVME virtual disk.
Because speed on large directories is important to me, I have created a mirrored "special" vdev which consists of two virtual NVME devices as a mirror (of cause on two different physical devices).
Another nice feature (I think) is that I have added some vdev_id's so that I can see which slots my drives are in... which is handy when replacing disks.
My ZFS versions looks like this:
zfs-0.8.3-1ubuntu12.12
zfs-kmod-0.8.3-1ubuntu12.12

And my pool looks like this:

Code:

  pool: aggr0
 state: ONLINE
  scan: resilvered 6.12T in 11 days 12:30:08 with 0 errors on Mon Jun  7 03:31:04 2021
config:

    NAME         STATE     READ WRITE CKSUM
    aggr0        ONLINE       0     0     0
      raidz3-0   ONLINE       0     0     0
        0a-0     ONLINE       0     0     0
        0a-1     ONLINE       0     0     0
        0a-2     ONLINE       0     0     0
        0a-3     ONLINE       0     0     0
        0a-4     ONLINE       0     0     0
        0a-5     ONLINE       0     0     0
        0a-6     ONLINE       0     0     0
        0a-7     ONLINE       0     0     0
        0a-8     ONLINE       0     0     0
        0a-9     ONLINE       0     0     0
        0a-10    ONLINE       0     0     0
        0a-11    ONLINE       0     0     0
        0a-12    ONLINE       0     0     0
        0a-13    ONLINE       0     0     0
        0a-14    ONLINE       0     0     0
        0a-15    ONLINE       0     0     0
        0a-16    ONLINE       0     0     0
        0a-17    ONLINE       0     0     0
        0a-18    ONLINE       0     0     0
        0a-19    ONLINE       0     0     0
        0a-20    ONLINE       0     0     0
        0a-21    ONLINE       0     0     0
        0a-22    ONLINE       0     0     0
        0a-23    ONLINE       0     0     0
    special
      mirror-1   ONLINE       0     0     0
        nvme0n1  ONLINE       0     0     0
        nvme2n1  ONLINE       0     0     0
    cache
      nvme1n1    ONLINE       0     0     0

The question is of cause, how much of this can be added into TrueNAS ?
Here I am especially thinking of the "special" vdev, and the vdev_ids...

 

[sretalla]

The question is of cause, how much of this can be added into TrueNAS ?

TrueNAS 12 CORE supports special VDEVs and cache drives (OpenZFS 2.0.4, I think), so importing it would seem to be possible... depending on the enabled zfs features/version.

 

[beardmann]

OK, my version seems to be 5.
But what about the vdev_id? As you can see from my zpool it shows 0a-? as the disk IDs which represents the slot in the disk shelf.
This is done in /etc/zfs/vdev_id.conf which looks like this:

multipath no
topology sas_direct
phys_per_port 4
slot bay
enclosure_symlinks yes
channel 03:00.0 0 0a-

When I create the zpool, I of cause use the /dev/disk/by-vdev/....
The question is, if TrueNAS will pick this up? I guess it will not do this automatically, and I might have to somehow enable vdev_id's before I import the pool... and maybe even import it manually from the command line...
Given this is a virtual machine, I am very tempted to just give this a try... what could go wrong? ;-)

 

[sretalla]

The question is, if TrueNAS will pick this up? I guess it will not do this automatically, and I might have to somehow enable vdev_id's before I import the pool.

It probably will.

Given this is a virtual machine, I am very tempted to just give this a try... what could go wrong? ;-)

Very little to go wrong if you just run zpool import at the CLI and have a look at what is found... nothing else will happen until you actually select a pool to import (preferable to do in the GUI anyway), so I can't see a reason not to at least have a look.