A seperate ZFS question

[Ultima]

-n is your friend. Never used zpool add without it to verify changes are as
you intend. Not using it first is similar to jumping off a plane without
verifying your parachute is on properly.

On Fri, Apr 28, 2017 at 9:52 AM, Trond Endrestøl <
Trond.Endrestol at fagskolen.gjovik.no> wrote:

> On Fri, 28 Apr 2017 14:14+0100, Paul Macdonald wrote:
>
> >
> > I fat fingered adding a cache drive and was unable to remove the SSD
> cache
> > drive (ada2)
> >
> > I added a 2nd SSD (ada3) for safety as i didn;t want to risk the pool at
> all
> > and exporting wasn;t feasible in timescale.
> >
> > Can someone explain :
> >
> >             what i've actually managed to set up here (!),
> >
> >             the ramifications of forceably offlining/removing ada2
> >
> >             and if i should worry when ada2 gets full?
> >
> >                  capacity     operations    bandwidth
> > pool          alloc   free   read  write   read  write
> > ------------  -----  -----  -----  -----  -----  -----
> > zrootnew       692G   460G     15    174   351K  2.40M
> >   mirror       683G   237G     14    138   328K  1.43M
> >     gpt/zfs0      -      -      6     50   155K  1.44M
> >     ada1p3        -      -      7     50   176K  1.44M
> >   ada2        9.17G   223G      0     36  22.9K   989K
> > cache             -      -      -      -      -      -
> >   ada3        39.0G   194G     23      5   168K   264K
>
> First, you have gpt/zfs0 and ada1p3 in a mirrored configuration. Next,
> you have ada2 striped (RAID 0) to the first pair of mirrors. This is a
> very weird "RAID 1 + 0" combo. Guess what will happen when you lose
> ada2!
>
> Maybe you should describe what you wanted to happen in the first
> place.
>
> If you really wanted a three-way mirror, you have just learned the
> hard way about the difference between zpool add and zpool attach.
>
> The latter is for adding additional members to existing mirrors, while
> the former is for adding raidz{1,2,3} groups to a pool, and the add
> command got you into this mess.
>
> "zpool attach zrootnew ada1p3 ada2" is the right command if you wanted
> to create a three-way mirror in the first place.
>
> I suggest you make good backups of this pool, destroy it, recreate it
> properly, and restore the missing data.
>
> --
> +-------------------------------+------------------------------------+
> | Vennlig hilsen,               | Best regards,                      |
> | Trond Endrestøl,              | Trond Endrestøl,                   |
> | IT-ansvarlig,                 | System administrator,              |
> | Fagskolen Innlandet,          | Gjøvik Technical College, Norway,  |
> | tlf. mob.   952 62 567,       | Cellular...: +47 952 62 567,       |
> | sentralbord 61 14 54 00.      | Switchboard: +47 61 14 54 00.      |
> +-------------------------------+------------------------------------+
> _______________________________________________
> freebsd-questions at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to "freebsd-questions-
> unsubscribe at freebsd.org"
>