[rescue] SSA1xx and "larger" SCSI drives

Don Y dgy at DakotaCom.Net
Mon May 8 10:42:26 CDT 2006

Steve Sandau wrote:
> I dropped an 18G drive into my SSA100 this morning since there had been 
> some discussion about the drive size in an SSA being limited to 9 gigabytes.
> The drive in the SSA is reported as 16.00G:
> 2   backup  wu     0 - 27636     16.00GB  (27637/0/0) 33551318
> whereas an 18G drive in my U2 is reported as 16.96G:
> 2   backup  wm     0 - 12389     16.96GB  (12390/0/0) 35559300

Cool!  What version of Solaris are you running?  SSA's firmware
version?  etc.?

> They are not identical drives, since I don't have identical drives handy 
> for this experiment. Maybe there is some kind of limitation, but I have 
> only tested one drive.
> A 4.2G drive shows as 4.00G (same as my Ultra1) and a 9G drive shows up 
> as 8.4G. I think that's normal, too.

Could be G = 1000*1000*1000 vs 1024*1024*1024 discrepancy...
Can you verify the drives' (plural) geometries sector counts
correspond to those reported by the SSA & U2?  Note that
33551318 : 35559300 :: 16.00 : 16.96!  (encouraging if those
sector counts are correct!)

> Now I have to hunt up a 36G drive and see what it tells me. Hmm. We're 
> supposed to get six 146G drives soon. Maybe I could borrow one for a few 
> minutes and try it out.
> Also worth noting (to me at least): the drawers have crosspieces 
> (braces) at the top and kind of divide the disk slots in each drawer 
> into two pairs and two triples. That makes it look like at least four 
> 1.6" drives could fit in each drawer.

Not without modifying the backplane -- or, selecting 1.6"
drives for "special characteristics".  The SCA connector
for the drive "above" the 1.6" drive that you are installing
will interfere with the case of the drive and prevent the
drive from fully engaging its own SCA connector.

This is the same "problem" that prevents using half height
drives in SS5/20, etc.  (the "solution" is to remove the
offending connector!)  I have a spare set of drawers so,
if this "experiment" proves fruitful, may undertake
modifying them for half height drives...

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