zfs discuss - Oct 2011 - ZFS in front of MD3000i

We''re setting up ZFS in front of an MD3000i (and attached MD1000
expansion trays).

The rule of thumb is to let ZFS manage all of the disks, so we wanted
to expose each MD3000i spindle via a JBOD mode of some sort.

Unfortunately, it doesn''t look like the MD3000i this (though this[1]
post seems to reference an Enhanced JBOD mode....), so we decided to
create a whole bunch of RAID0 1-disk LUNs and expose those.  Great..
except that the MD3000i only lets you create 16 LUNs and we have 44
disks total. :)

Anyone tried this?  I guess our best bet will be to just do all the
RAID stuff on the MD3000i and export one LUN to ZFS.

Ray

[1] http://don.blogs.smugmug.com/2007/10/01/dell-md3000-great-das-db-storage/

On Mon, Oct 24, 2011 at 5:45 PM, Ray Van Dolson <rvandolson at esri.com>
wrote:
> Unfortunately, it doesn''t look like the MD3000i this (though
this[1]
> post seems to reference an Enhanced JBOD mode....), so we decided to
> create a whole bunch of RAID0 1-disk LUNs and expose those. ?Great..
> except that the MD3000i only lets you create 16 LUNs and we have 44
> disks total. :)
>
> Anyone tried this? ?I guess our best bet will be to just do all the
> RAID stuff on the MD3000i and export one LUN to ZFS.
    When i have run into this kind of problem (a RAID unit that either
does not support JBOD or one drive per LUN or enough LUNs), I usually
carve the array disks into small sets of RAID0 and present those to
ZFS. Currently I am reusing some old Sun 3511 arrays, each loaded with
12 x 500GB drives. The 3511 supports one drive LUNs, but discourages
their use (it is for support use only according to the documentation),
so I created RAID0 sets of 2 drives each and ZFS sees 6 x 1TB LUNs.
ZFS then provides my redundancy and data integrity.

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