[rescue] SSA1xx and "larger" SCSI drives

Steve Sandau ssandau at gwi.net
Mon May 8 11:50:40 CDT 2006

>>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.?

This is Solaris 9. I don't know how to find the SSA's firmware version, 
though. It's in the next room, so I am happy to find it if you know how 
I can.

>>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!)

Seagate seems to have disowned this drive. Other drives in this size 
have 512bytes per cylinder, but do not give a cylinder count. A Dell 
blade reports 33554432 sectors for the Cheetah (ST318305LC) that I tried 
in the SSA. Apparently some other "18G" drives have a slightly larger 
capacity than these? The other drive in the Dell is a Fujitsu 3184mc and 
it appears to have 35566487 sectors.

>>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.

This is probably the thing to do, since "18G" drives seem to vary in 
number of 512 byte sectors. So, I don't know if I have hit a sector 
count limit here, or if the drive is just different. Here is the info 
from a Fujitsu 18G drive (mentioned above) in the SSA:
2   backup  wu     0 - 24126     16.96GB  (24127/0/0) 35563198

Looks like the SSA loses a few sectors compared to the Dell? (Sorry, 
can't use the U2 for comparison; it is at home and I am not.)

>>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.

I was unable to find a 1.6" drive to try out. Now I don't feel so bad 
about that. ;-)


More information about the rescue mailing list