Re: ZFS pool creation in a large disk

[Brad Spencer <brad%anduin.eldar.org@localhost>]

Rocky Hotas <rockyhotas%firemail.cc@localhost> writes:

> Hi!
> This wiki page
>
>  <https://wiki.netbsd.org/users/mlelstv/using-large-disks/>
>
> deals with disks greater than 2 TB.
> I have such a disk, which currently has a GPT table and a couple of
> unused partitions. I would like to create a ZFS pool which uses it
> entirely, and be able to export this pool (to be imported in another
> system, for example FreeBSD, as already discussed in another thread).
>
> I would naively erase the whole disk /dev/wd1, thus deleting the GPT,
> and then create a pool with `zpool create <pool_name> /dev/wd1': this
> way, however, I am not sure that a disk with no filesystem and no
> partition table would be accepted.
>
> On the other hand, if I keep GPT, create a single FFSv2 partition, and
> then `zpool create <pool_name> /dev/wd1', I am not sure that an external
> system would read/write this pool (it may not know, or may not be
> compatible with, FFSv2).
>
> Which is, then, a correct way (hopefully the best way) to accomplish
> this?
>
> Bye!
>
> Rocky

This will somewhat come down to what the receiving system will use when
going a scan on the devices when you do the 'zpool import'.  I did test
for this at one point, but my memory is a bit foggy...  I think I ended
up putting a GPT partition on the filesystem and FreeBSD was happy to
import that (i.e. 'zpool import' worked as expected).  I don't remember
if a putting it on a raw chunk of disk did that.  But I may be
misremembering with SmartOS (did the same test there).


BTW - it is very simple to test for this without using a disk.  It is
very much the case that zpool will create a pool on a file and you
should be able to just copy the file around.  It may be another matter
completely if the file can be labeled with a GPT partition (in NetBSD
this is trival), but other OSs may be another matter.



-- 
Brad Spencer - brad%anduin.eldar.org@localhost - KC8VKS - http://anduin.eldar.org