All-
I've got some questions about sharing (splitting) a StorageWorks RAID array
410 between two hosts in a *non* dual-redundant configuration. I'm hoping
someone else out there is doing what we intend to do with our array, and that
you might be able to point out any trouble spots with what we're planning.
We essentially want to have part of the array used by one host and another
part of the array accessed by another host, simultaneously.
We currently have the RAID array connected to a Digital Unix 3.2x machine.
There is currently one controller in the array, an HSZ40, configured like
such:
swxrc>
Controller:
HSZ40 ZG50100XXX Firmware V25Z-0, Hardware A02
Not configured for dual-redundancy
SCSI address 7
Time: NOT SET
Host port:
SCSI target(s) (0), Preferred target(s) (0)
Cache:
32 megabyte write cache, version 2
Cache is GOOD
Battery is GOOD
Unflushed data in cache
CACHE_FLUSH_TIMER = 65535 (seconds)
CACHE_POLICY = A
swxrc>
We have the bottom two (of the four) shelves in the 410 populated with drives,
and we currently have the bottom row as one RAID set (so the set is
split across all six of the internal SCSI buses), like this:
swxrc>
Name Type Port Targ Lun Used by
------------------------------------------------------------------------------
DISK100 disk 1 0 0 RAIDS0
DISK110 disk 1 1 0 SPARESET
DISK200 disk 2 0 0 RAIDS0
DISK210 disk 2 1 0
DISK300 disk 3 0 0 RAIDS0
DISK310 disk 3 1 0
DISK400 disk 4 0 0 RAIDS0
DISK410 disk 4 1 0
DISK500 disk 5 0 0 RAIDS0
DISK510 disk 5 1 0
DISK600 disk 6 0 0 RAIDS0
DISK610 disk 6 1 0
swxrc>
To connect the array to a second host, we've ordered an HSZ50 and a BA350-MA
controller shelf.
Now the questions.
1) We've been assured by various sales people that it's OK to mix HSZ40 and
HSZ50 controllers in the same array, but I'm still nervous about it. Is
anyone doing this? We plan to upgrade our HSZ40 to an HSZ50 sometime within
the next few months, but until we do that can we operate with two different
types of controllers in the same 410 array?
2) Since we're not operating in dual-redundant mode, I'm assuming that it's
not necessary that we keep the version of the firmware on the controllers at
the same level. Is this a valid assumption?
We will be upgrading the firmware that's currently on the HSZ40 to version 3.1
(which we have), but the version of the firmware for the HSZ50 is at least
version 5.1, so it seems impossible to keep the firmware versions strictly
in sync.
3) The BA350-MA "User's Guide" mentions the StorageWorks 8xx and 5xx arrays,
but there is no mention of a 4xx array, like the 410 we have. Based on what
I can tell from the "SWXSC-AA Office Expansion RAID Enclosure User's Guide"
that came with our 410, it appears very similar to the SW3xx cabinet. The
410 comes with space within the card cage assembly for two controllers that
fit the HSZ40 form-factor.
It appears to me at this point like the BA350-MA controller shelf will *not*
work in the 410 array, and that the salesperson was wrong in telling my boss
that we needed a BA350-MA controller shelf for our array. Can anyone
confirm this?
4) From what I can tell, the HSZ50 controller form-factor is very similar to
the HSZ40 controller form-factor, with the exception of the cache battery.
If my guess is correct and we *can't* use the BA350-MA shelf in our 410,
can we install the HSZ50 at all, or is the form-factor different enough so
that it will not work in the unused slot built into the bottom of the 410
array?
5) Assuming we somehow get to the point where we have two controllers in
our RAID array, would it be advisable to leave the *current* raidset as-is,
or would I be better off rearranging the raidset so that the original
controller has the raidset that is on the array's internal buses 1-3 (for
example) and the new controller has a raidset that is on buses 4-6? What I'm
essentially asking is if it's wise to have both controllers simultaneously
using devices on all six of the internal buses, or if I would be better of
having one controller only use devices on certain buses and the other
controller only use devices on the remaining buses.
Thanks for any tips anyone can provide!
Tim
--
Tim Mooney mooney_at_dogbert.cc.ndsu.NoDak.edu
Information Technology Services (701) 231-1076 (Voice)
Room 242-J1, IACC Building (701) 231-8541 (Fax)
North Dakota State University, Fargo, ND 58105-5164
Received on Fri Apr 25 1997 - 05:18:12 NZST