zpool to upgrade or not to upgrade

[cinjun]

I'm running two zpools with ZoL, one is version 28 and one is the most current. The message:

status: The pool is formatted using a legacy on-disk format.  The pool can
        still be used, but some features are unavailable.

is getting annoying. Is there any reason not to upgrade? What is the probability of this corrupting my pool?

 

[danswartz]

No reason not to unless you are moving to closed solaris. I can't imagine it corrupting it.

 

[Aesma]

The reason is compatibility with other implementations. Personally I keep the message (on OpenIndiana).

 

[danswartz]

AFAIK, ZoL and freebsd have the same current version (5000). The only open distro I know of that would add features not in the other two is a recent illumos kernel.

 

[bmh.01]

Afaik all the open versions of zfs are running the feature flags version 5000.

 

[danswartz]

The version isn't the relevant issue. Even at 'version 5000', one distro can have a named feature not present in another and hence, not usable (possibly) by that other. Example: I have a ZoL pool and an omnios pool:

ZoL:

tank feature@async_destroy enabled local
tank feature@empty_bpobj active local
tank feature@lz4_compress active local
tank feature@multi_vdev_crash_dump disabled local
tank feature@spacemap_histogram disabled local
tank feature@enabled_txg disabled local
tank feature@hole_birth disabled local
tank feature@extensible_dataset disabled local
tank feature@bookmarks disabled local

Note the 'disabled' ones are because this is a ZoL pool on an omnios system.

omnios:

rpool feature@async_destroy enabled local
rpool feature@empty_bpobj active local
rpool feature@lz4_compress enabled local
rpool feature@multi_vdev_crash_dump enabled local
rpool feature@spacemap_histogram active local
rpool feature@enabled_txg active local
rpool feature@hole_birth active local
rpool feature@extensible_dataset enabled local
rpool feature@bookmarks enabled local

 

[blazemonkey]

I'm running NAS4Free and just upgraded my vpool today. I don't know much about ZoL, but with NAS4Free, it only took a few seconds and it was fine.

I did have to "clear config & import disks" as they were apparently showing up with the wrong ID's, but this could have been from upgrading the OS earlier.