Score:0

Can I mirror a 2-disk striped zpool to a single large drive?

cl flag

Currently I have a 4TB pool with two striped drives:

# zpool status
  pool: lxd
 state: ONLINE
status: Some supported features are not enabled on the pool. The pool can
        still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
        the pool may no longer be accessible by software that does not support
        the features. See zpool-features(5) for details.
  scan: scrub repaired 0B in 0 days 02:00:22 with 0 errors on Sun Jul  9 02:24:24 2023
config:

        NAME                      STATE     READ WRITE CKSUM
        lxd                       ONLINE       0     0     0
          wwn-0x500a075122d7d68c  ONLINE       0     0     0
          wwn-0x5002538f4361b49b  ONLINE       0     0     0

I have a 4TB drive which I would like to mirror this pool to, to add redundancy. I have a hard time figuring out whether it's even possible. I tried the attach command:

# zpool attach lxd lxd /dev/disk/by-id/wwn-0x5002538f4361edfb
cannot attach /dev/disk/by-id/wwn-0x5002538f4361edfb to lxd: no such device in pool

But I'm unsure if I'm hitting a bug or if this is not the way (or even possible). Thanks.!

Score:1
ca flag

No, you can not nest vdev in this manner.

To get better redundancy without redoing your pool config and/or introducing lvm or md to concatenate your smaller drives, the best approach is to use send/recv to periodically copy all your data to the bigger drive.

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