josh@cayman.com (Josh Littlefield) (10/08/90)
Has anyone had experience connecting a Maxtor XT-8760S disk to an SLC (or other SUN)? The disk I have is sold by Rodime for use with Macintoshes. I'm having 2 levels of problems: geometry and termination. Geometry: First, I set the SCSI ID to 3 and connected the disk and everything seemed fine. Using the PROM "probe-scsi" command, it identified itself as a Maxtor XT-8760S (which is somewhat more than there doc. told me). I found an unsupported (read: commented out) entry for this disk in the OS 4.1 format.dat file, which I figured I'd use. When I tried to format the disk I got an error which the doc described as the controller objecting to the "Page 3 Mode Select" command. Neither Sun nor Rodime was able to pinpoint the objection. While I could format the disk on a Mac, I felt it would be better to format on the Sun and be sure of the number of formatted cylinders, etc. After some digging (and I mean deep) I found I could go into adb and stuff a non-zero value into a global variable to enable debugging info in format. This printed out each of the SCSI mode select commands and their parameters, as well as what I assume to be the defaults indicated by the controller. I found when I changed the number of sectors/track from 54 to 53, the controller was happy. But now I'm left dreaming up the partitioning stuff myself. Anyone know what the goals of this should be? Anyone know why most disks with, for example, 1632 cylinders only format 1614 cylinders with 2 aux cyls? Anyone know if this Maxtor really has only 53 sectors/track? ** Rodime just called back (after >week) and said the disk has a variable number of sectors/track -- varying from outside to inside. What does this mean for the OS? Is this a problem? Termination: I found when I daisy-chained a tape drive (brand new Archive 150 Sun 1/4") between the SLC and the disk I got occasional errors: esp0: 3.0 data transfer failure Stat=0x10<XZERO>, Intr=0x10<BUS> Last state='UNKNOWN', Last cmd='dma tran_info' DMA addr=0xff06b000, last=0xff069000;Dma CSR=0x8 Mapped Dma Space: Base = 0xff069000 Count = 0x2000 Transfer History: Base = 0xff069000 Count = 0x2000 These seemed related to writing to the disk, but not every write. The Maxtor has internal termination (yes, I double checked). I am told by Sun hardware support that the SLC provide term power. After a few of these I power cycled everything, and was able to dump my entire disk to tape. But on attempting to restore, I continued to get these errors, and SCSI resets and restore kept crapping out. ** Rodime finally admits to jumpers for term power options. I'll play with these. I assume I want no term power from the disk if the SLC supplies it? Any recommendations? Josh Littlefield Cayman Systems, Inc. University Park at MIT josh@cayman.com 26 Landsdowne Street (617) 494-1999 Cambridge, MA 02139