Using GTP and glabel for ZFS arrays

[Dan Langille]

On 7/22/2010 8:47 PM, Dan Langille wrote:
> Thank you to all the helpful discussion.  It's been very helpful and
> educational. Based on the advice and suggestions, I'm going to adjust my
> original plan as follows.
>
> NOTE: glabel will not be used.
>
>
> First, create a new GUID Partition Table partition scheme on the HDD:
>
> gpart create -s GPT ad0
>
>
> Let's see how much space we have. This output will be used to determine
> SOMEVALUE in the next command.
>
> gpart show
>
>
> Create a new partition within that scheme:
>
> gpart add -b 1024 -s SOMEVALUE -t freebsd-zfs -l disk00 ad0
>
> The -b 1024 ensures alignment on a 4KB boundary.
>
> SOMEVALUE will be set so approximately 200MB is left empty at the end of
> the HDD. That's part more than necessary to accommodate the different
> actualy size of 2TB HDD.
>
> Repeat the above with ad1 to get disk01. Repeat for all other HDD...
>
> Then create your zpool:
>
> zpool create bigtank gpt/disk00 gpt/disk02 ... etc
>
>
> This plan will be applied to an existing 5 HDD ZFS pool. I have two new
> empty HDD which will be added to this new array (giving me 7 x 2TB HDD).
> The array is raidz1 and I'm wondering if I want to go to raidz2. That
> would be about 10TB and I'm only using up 3.1TB at present. That
> represents about 4 months of backups.
>
> I do not think I can adjust the existing zpool on the fly. I think I
> need to copy everything elsewhere (i.e the 2 empty drives). Then start
> the new zpool from scratch.
>
> The risk: when the data is on the 2 spare HDD, there is no redundancy. I
> wonder if my friend Jerry has a spare 2TB HDD I could borrow for the
> evening.
>

The work is in progress.  Updates are at 
http://beta.freebsddiary.org/zfs-with-gpart.php which will be updated 
frequently as the work continues.

-- 
Dan Langille - http://langille.org/