[SunRescue] Max. Size Hard Disk Installable in SparcStorage Array Model 100?

[Jonathan Katz]

Earlier today you wrote:
> Now that I've got my SparcServer 1000 running, I'd like
> to try the Storage Array that came with it (It looks like
> a model 100, but the model number on the back indicates
> model 1010) . I did a doc search on the sun web site,

Check this out:
http://docs.sun.com:80/ab2/@LegacyTocView?toc=SUNWab_52_4%3A%2Fsafedir%2Fspace3%2Fcoll2%2FSUNWassa%2Ftoc%2FARRAYCONFG%3AARRAYCONFG%3Aclose;bt=SPARCstorage+Array+Configuration+Guide&Ab2Lang=C&Ab2Enc=iso-8859-1

That's the instruction manual you're looking for.

I guess I'm now the Network Storage Representative. Folks
who are more in the know than I please contradict me if I
get things wrong...

As a model '1010' they shipped with 1GB disks. As a '1020'
they shipped with 2G disks, and so on... except I think the
largest drives these shipped with were 4GB. You should be
able to cram *any* size SCA SCSI-SE drive in there IIRC,
just make sure the mounting brackets line-up. These are just
really SCSI JBODs and use a fibre-based SCSI connection to
go form the host (your SS1000) to the SSA.

For those interested
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1208375054
is a good, overpriced idea of what we're dealing with.

> Also, is there any required order in which the disks need
> to be installed in the 3 drawers?

There is no *required* order, but there are more optimum
ways of installing disks and laying out filesystems for
reliability and performance.

> Any other suggestions on use/setup of this thing would
> be greatly appreciated :-)

Here goes-- are you more interested in performance or total
disk space available?  If you're into space (like I am) and 
don't mind the performance hit of RAID5, go with a RAID5
setup. If you need the performance go with a RAID 0+1
(striping+mirroring) setup. The trick to getting the maximum
speed out of either setup is to strip and mirror across
controllers/channels.

Each array has six channels. (I think it comes out to three
real controllers w/ 2 channels a piece, each controller runinng
the length of the array-- t0 & t1 would be on the same controller.)
To get maximum speed on a RAID5 stripe you want to stripe across
those channels. To get maximum speed and reliability across a 0+1
set you need to do the same thing.

Let's take a look at the physical layout. Pardon my ASCII:

 ( back of unit )
     t0 t2 t4
     []|[]|[] d0
     []|[]|[] d1
     []|[]|[] d2
     []|[]|[] d3
     []|[]|[] d4
     -- -- --
     t1 t3 t5
     []|[]|[] d0
     []|[]|[] d1
     []|[]|[] d2
     []|[]|[] d3
     []|[]|[] d4
 ( front of unit )

If you're to do RAID5 you'll stripe from c1t0d0 to c1t2d0 to
c1t4d0 to c1t1d0 to c1t3d0 and so-on. If you're doing 0+1 and
really want to worry about reliability you need to mirror and
stripe across the channels. This gets a little more tricky.
You'll want to mirror from a disk on t0 to a disk on t2, t3,
t4 or t5. This is in case the power fails to the tray which
holds t0/t1, the mirror will be on a different tray and all 
will be swell.

If you look through the HA (SunCluster 2.2 Documentation)
there is a really good reference on Sun storage devices,
their configurations, and layout.

Good luck.

-Jon
--
Jonathan Katz
e-mail: jon at jonworld.com 
website: http://jonworld.com
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