SCSI bus failures on 3/60

[August Depner]

I'm having a problem with upgrading from a 3/50 to a 3/60 on our network:
the 3/60 reports SCSI bus errors after a few hours and takes the drives
offline.  If anyone can help, I would greatly appreciate it and I'll
summarize the responses.

We've been running a 3/50 under 3.5 OS (yeah, I know) for several months
as a file server.  We have it connected to a Sigma tower containing a CDC
Wren IV, a Hitachi DK515C and a cartridge tape drive.  No problems.

As soon as we upgraded to a 3/60, we received the following errors:

/: file system full
/: file system full
{this goes on for awhile}
si 0: Si_cmd: no command phase
si 0: resetting scsi bus
	  last phase=0x81 (Arbitration)
	  csr=0x40f bcr=8192 tcr=0x6
	  cbsr=0x7 (DATA_IN) cdr=0x81
	  nr=0x0 bsr=0x0
	  target=1, 1nn=0 DMA addr=0x2000
	  count=8192 (8192)
	  cdb= a 4 83 d0 10 0

sd0: scsi bus failure
si0: sd0, unit offline
sda: write retry, blk 15616 (abs blk 15616)
	 sense key (0x6): unit attention,
	 errorcode(0x29):reset
panic: hard IO err in swap
syncing disks " " " done
dumping to dev 701, offset 31948
Exception 0x7c at 0x0F0043F4
{etc....} as the unit fails and reboots sometimes, other times
just hangs...

We're thinking that the clock speed on the 3/60, being faster than the
3/50, is too fast for the disk.  Our SUN FE says our disks are unsupported
by SUN, so they can't fix it, though the service manager did offer to look
through some bug lists. We're using a fairly standard kernal, though the
3/60 has color instead of monochrome.  I'm wondering if anyone out there
knows about this problem and if so, can they offer a fix?

In-Real-Life: August Depner, Thalatta Corporation, (+1 206 455 9838)
Domain: depner at Thalatta.COM   Path: ...!sun!sunup!thebes!depner