IRIS 3030 Disk Problems

[Mark Bradley]

In article <8908221806.AA03436 at aero4.larc.nasa.gov>, blbates at AERO4.LARC.NASA.GOV ("Brent L. Bates AAD/TAB MS294 x42854") writes:
> 
>    We currently have two Hitachi 512-17, 170Mb drives.  We plan to replace
> our system disk with a Hitachi DK514-38, 380Mb drive.  If this works, we
> will probably replace our other disk too.  I have received email from
> Jim Diamond indicating that we should be able to replace our data drive
> with out any problems, however we weren't sure about the system disk.
> This is why we ordered only one drive, if the drive doesn't work as a
> system disk, then we will use it as a data disk.  However, if it does
> work as a system disk, then we will probably get the second drive.
>    Not too long ago I found out that there seems to be a problem with
> using two 380Mb drives.  SGI said that the current hardware and 3.6 OS
> will support two 380Mb drives.  I talk to someone that actually tried
> to do this, and the system keep crashing.  It turned out that there was
> a bug some ROM's.  I don't know when or if the correction got into any
> other machines or not.  We plan to cross that bridge when we get to it.

You should save yourself some cash by not trying to use the 514-38 on
your 3030.  It is a 15 MHz xfer rate drive.  The controller in your 3030
(unless you bought something from a vendor other than SGI) will only
support 10 MHz xfer rate disk drives.  The drives will kind-of-sort-of
work a bit, but will eventaully scrog your data and offer all kinds of
wonderful 'sector not found's and 'header not found's and read and
write errors of various sorts.  The 514-38 is a very good drive, tho.
Too good for that archaic controller design (although it was the hottest
game in town in its time).  The only 380's that will work reliably on
the 3030 or 3130 are 10 MHz flavors, and you will have to give up some
capacity due to larger gap requirements.  That is, you will have to run
at 32 sectors/track even though most drives can be hard-sectored to as
high as 36 sectors/track.  Good luck.

					markb


--
Mark Bradley				"Faster, faster, until the thrill of
IO Subsystems				 speed overcomes the fear of death."
Silicon Graphics Computer Systems
Mountain View, CA			     ---Hunter S. Thompson