moj@mirfak.utu.fi (Matti Jokinen) (06/07/90)
I am looking for instructions on installing a CDC Wren VII 94601-12G disk on a Sun-4 running SunOS 4.0.3. Especially, I would like to know how to write the entries in /etc/format.dat. Wren VII has an unusual geometry: bit density is constant and the number of sectors per track is variable. I wonder if it really is possible to get optimal performance under SunOS. Matti
kusumoto@chsun1.uchicago.edu (Bob Kusumoto) (06/08/90)
moj@mirfak.utu.fi (Matti Jokinen) writes: >I am looking for instructions on installing a CDC Wren VII 94601-12G disk >on a Sun-4 running SunOS 4.0.3. Especially, I would like to know how to >write the entries in /etc/format.dat. Wren VII has an unusual geometry: >bit density is constant and the number of sectors per track is variable. >I wonder if it really is possible to get optimal performance under SunOS. just a quick note, I wrote a message that's in the sun-spot archives about this. I don't have a copy but I'll gloss over it real quick. in format.dat, you can add an entry to look like: disk_type = "CDC Wren VII 94601-12G" \ : ctlr = MD21 : fmt_time = 4 : cache = 0x11 \ : ncyl = 1925 : acyl = 2 : pcyl = 1931 : nhead = 15 : nsect = 70 \ : rpm = 3600 : bpt = 41301 you can change the nsect parameter to try and push more space on your drive, although I doubt and highly do not recommend that you increase it to the theoretical max of 80. the format program will not "format" correctly. It will time out if you issue the format command in the format program. You can analyze the disk, call up the original defect list, and label the disk with the proper label and partition info. Beyond that, you're outta luck. Someone told me once that you can write the defect list by using sundiag, but I have no idea as to what this entails. Bob Bob Kusumoto | Find the electric messiah. Internet: kusumoto@chsun1.uchicago.edu | The AC-DC God. Bitnet: kusumoto@chsun1.uchicago.bitnet | --- My Life with the Thrill Kill UUCP: ...!{oddjob,gargoyle}!chsun1!kusumoto | Kult, "Kooler than Jesus"
chris@com50.c2s.mn.org (Chris Johnson) (06/09/90)
In article <kusumoto.644788853@chsun1> kusumoto@chsun1.uchicago.edu (Bob Kusumoto) writes: >moj@mirfak.utu.fi (Matti Jokinen) writes: >>I am looking for instructions on installing a CDC Wren VII 94601-12G disk >>on a Sun-4 running SunOS 4.0.3. Especially, I would like to know how to >>write the entries in /etc/format.dat. Wren VII has an unusual geometry: >>bit density is constant and the number of sectors per track is variable. >>I wonder if it really is possible to get optimal performance under SunOS. > >just a quick note, I wrote a message that's in the sun-spot archives about >this. I don't have a copy but I'll gloss over it real quick. > >in format.dat, you can add an entry to look like: > >disk_type = "CDC Wren VII 94601-12G" \ > : ctlr = MD21 : fmt_time = 4 : cache = 0x11 \ > : ncyl = 1925 : acyl = 2 : pcyl = 1931 : nhead = 15 : nsect = 70 \ > : rpm = 3600 : bpt = 41301 > >you can change the nsect parameter to try and push more space on your drive, >although I doubt and highly do not recommend that you increase it to the >theoretical max of 80. > Here's the entry I use here with Wren VII's running under SunOS 4.0.3c on our Sparcstations. It works just fine, and note that it uses a bit more of the available disk space. disk_type = "Imprimis Wren VII 94601-15" \ : ctlr = MD21 : fmt_time = 4 \ : cache = 0x11 : trks_zone = 15 : asect = 0 \ : ncyl = 1947 : acyl = 2 : pcyl = 1949 : nhead = 13 : nsect = 80 \ : rpm = 3597 : bpt = 41301 -- ...Chris Johnson chris@c2s.mn.org ..uunet!bungia!com50!chris Com Squared Systems, Inc. St. Paul, MN USA +1 612 452 9522
kusumoto@chsun1.uchicago.edu (Bob Kusumoto) (06/12/90)
chris@com50.c2s.mn.org (Chris Johnson) writes: >disk_type = "Imprimis Wren VII 94601-15" \ > : ctlr = MD21 : fmt_time = 4 \ > : cache = 0x11 : trks_zone = 15 : asect = 0 \ > : ncyl = 1947 : acyl = 2 : pcyl = 1949 : nhead = 13 : nsect = 80 \ > : rpm = 3597 : bpt = 41301 I strongly advise against using this format.dat entry. The MD21 controller needs 4 cylinders (I don't remember the reason). But the cyl parameters should be: ncyl + acyl + 4 = pcyl I was told from my distributor that the total number of physical cylinders was 1931, rather than the 1949 listed here, probably because he has a 1.5GB version rather than my 1.2GB drive (the model number on my drive is 94601-12G). Call your dealer and ask for some of the parameters, such has the number of physical cylinders, the number of heads, the number of bytes per track, the rpm of the drive. Go figure from there. Bob Bob Kusumoto | Find the electric messiah. Internet: kusumoto@chsun1.uchicago.edu | The AC-DC God. Bitnet: kusumoto@chsun1.uchicago.bitnet | --- My Life with the Thrill Kill UUCP: ...!{oddjob,gargoyle}!chsun1!kusumoto | Kult, "Kooler than Jesus"
funke@turing.toronto.edu (Mark Funkenhauser) (06/13/90)
In article <kusumoto.645123803@chsun1> kusumoto@chsun1.uchicago.edu (Bob Kusumoto) writes: >chris@com50.c2s.mn.org (Chris Johnson) writes: >>disk_type = "Imprimis Wren VII 94601-15" \ >> : ctlr = MD21 : fmt_time = 4 \ >> : cache = 0x11 : trks_zone = 15 : asect = 0 \ >> : ncyl = 1947 : acyl = 2 : pcyl = 1949 : nhead = 13 : nsect = 80 \ >> : rpm = 3597 : bpt = 41301 > >I strongly advise against using this format.dat entry. The MD21 controller MD21 controller? What's this? This sounds like an Emulex product number. Wren scsi disk drives do not need external (Emulex) scsi controller boards. The scsi controller board is a builtin on the disk drive. Unless you are implying that the Wren VII uses the MD21 controller as its builtin controller board ?? >needs 4 cylinders (I don't remember the reason). But the cyl parameters >should be: > > ncyl + acyl + 4 = pcyl > It is possible that the Wren VII is formatted with 4 alternate cylinders, but on the Wren V and Wren VI I've only seen it formatted with 2 alternate cylinders. Two alternates is plenty. >I was told from my distributor that the total number of physical cylinders >was 1931, rather than the 1949 listed here, probably because he has a 1.5GB >version rather than my 1.2GB drive (the model number on my drive is 94601-12G). The only number I've ever seen for the Wren VII is 94601-12G. Seagate, which took over the Imprimis products, now calls it ST41200N. >Call your dealer and ask for some of the parameters, such has the number of >physical cylinders, the number of heads, the number of bytes per track, the >rpm of the drive. Go figure from there. This doesn't quite work for Wren SCSI disk drives as I will explain. The thing to remember about SCSI Wren drives is that come with a built in scsi controller. Most (if not ALL) of these scsi controllers format the disk with VARIABLE number of sectors per track. Thus, when you take the number of cylinders, number of heads and number of average sectors per track that Imprimis (or Seagate now) quotes in their product info and multiply them together, the numbers may not seem match exactly the quoted capacities. What you need to know is how the disk is *actually* formatted at the factory. Here at U of T we have machines (ICM3216) with which we can connect up scsi drives and determine how the disk was formatted including determining the maximum disk capacity. I admit that we have only purchased Wren V and Wren VI drives but they have always been pre-formatted with 512 byte sectors, 1 alternate sector per track and 2 alternate cylinders (e.g 32 alt tracks). I assume that when we order a Wren VII it will be pre-formatted similarly. (someone can correct me if I'm wrong). The trick to creating a format.dat entry for Wren scsi drives is to maximize the use of the available (e.g user accessible or logical) sectors on the disk. I've been told that this number for the Wren VII is 2026964 512-byte sectors. This number does NOT include the sectors of the alternate tracks (e.g. this number is the total logical data blocks on the disk). Thus once you have determined the ncyl number, you add 2 to get the pcyl number. Remember: scsi provides an interface where data is accessed by its logical block (sector) number, NOT the physical sector number NOR by (cylinder, head, sector). Therefore, we are free to choose any values for ncyl, nhead and nsect so that when they are multiplied out you get <= 2026964. Caveat: I am assuming that you are using format.dat to label the scsi disk, NOT re-format it. I'm not sure if this arbitrary use of ncyl, nhead and nsect can be used for re-format since I don't have the Wren product spec in front of me to check.
kusumoto@chsun1.uchicago.edu (Bob Kusumoto) (06/15/90)
The problem with installing a Wren VII on the sun is that you can't
"format" it using the format program. You can label the disk, you can
write a partition table for it, you can call up the defect list. But
how you do get the sun to recognize the defect list in the first place?
Does it have to know? Is the drive smart enough to avoid the defects or
do you have to use some program (someone suggested to me that I use sundiag)
to let the sun know where the defects are?
(if you try to "format" the drive, all I've been getting lately is SCSI
timeout errors after about a 1/2 hour of waiting)
Bob
Bob Kusumoto | Find the electric messiah.
Internet: kusumoto@chsun1.uchicago.edu | The AC-DC God.
Bitnet: kusumoto@chsun1.uchicago.bitnet | --- My Life with the Thrill Kill
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