Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!ucsd!hub.ucsb.edu!aks From: aks@nowhere.ucsb.edu (Alan Stebbens) Newsgroups: comp.unix.aix Subject: Re: Adding a 3rd party SCSI disk to an rs6000 Keywords: subclass disk rs6000 AIX Message-ID: <7022@hub.ucsb.edu> Date: 7 Nov 90 17:34:53 GMT References: <1149@cameron.egr.duke.edu> Sender: news@hub.ucsb.edu Organization: CCSE, Univ. of CA, Santa Barbara Lines: 113 In <1149@cameron.egr.duke.edu> jpe@egr.duke.edu (John P. Eisenmenger) writes: >I'm trying to figure out how to set up a WREN-VII for my RS6000. Has >anyone done this before? The problem, as I see it, is that I need to >define a new disk subclass in order to get little things like the disk's >size correct. How do I go about it? >I'm also having some troubles with a SCSI 8mm tape drive. It looks >like its configured (marked as available, correct subclass, and device >files are there), but whenever I try to access it I get: > /dev/rmt1: A system call received a parameter that is not valid. About the SCSI disk drive and its configuration: First, I don't believe that you need to add a new disk subclass. Using SMIT, I just added a new disk, using the "Other SCSI" as the disk type, then I added a new physical volume as well as a new volume root, since I wanted to be able to export this entire volume set. Using "Other SCSI", the system seemed to know how to read the SCSI parameter table from the disk drive and determine its size. Once you create a physical volume, you can either (a) add a new filesystem (which will automatically create logical volumes for you), or you can (b) create logical volumes and then create filesystems using "previously configured logical volume". I did (a) first only to discover that the default logical volume had a default name which I disliked, and more importantly a default size which didn't match the available size of the disk. It seems that the logical volume naming convention differs for the pre-installed systems from that used by default for SMIT. I like to have all logical volumes named consistently, so I ended up having to do it by hand. One thing which is missing from SMIT (at least on AIX 3.1), is the capability of changing the JFSLOG volume for a filesystem. I ended up having to discover how to do this by hand, by searching the scripts in the /etc and /usr/lpp/inst directories. This was so I could have the logical volume name used for the journal logging on my new hard disk be consistent with the name used for the other disks. As for the device errors: I have an RS6000/320 with three external SCSI devices attached on the same "scsi0" controller with two internally attached 320MB drives. If you read the install instructions for the SCSI controller, you'll note that you're not supposed to be doing what I've done. If you want more than two external devices AND two internal drives are already connected, you are supposed to purchase a second SCSI controller with which you can attach up to seven devices. Now that that has been said... I had this same problem on my new unit, which led me to RTFM and discover the above "limitation". I was above to give up, when it occurred to me that the accessibility of each device may depend upon the order in the chain, if the SCSI driver were at "its limit" in driving the SCSI bus signals. The SCSI cable from the CPU has piggy-back connector at the device end, which I'll label cable "1", with ends "A and "B". The "B" end has the piggy-back connector receptacle. The "A" end is the usual Centronics style "pinch-slot" connector. IBM also supplies a shorter SCSI daisy-chain cable with similar connectors: an "A" end, and a "B" piggy-back connector end. My first attempt at connecting all the SCSI drives was as follows: CPU [A]-----(1)------[B] 1/4" tape drive ----[A] (2) ----[B] CD-ROM ----[A] (3) ----[C] 720 MB SCSI Drive (Hitachi) Notes: Cable (3) is a "home-built" ribbon-cable with a Centronics style (pinch-slot) at end [A], and a 3x20 (DB60?) pin connector at end [C]. The Hitachi drive has an internal SCSI terminator, so no external terminator is needed. Anyway, the configuration above partially worked: the CPU could access the 1/4" tape drive, and the disk drive, but not the CD-ROM. So, I tried the following configuration, which is what I'm successfully using now: CPU [A]-----(1)------[B] CD-ROM ----[A] (2) ----[B] 1/4" tape drive ----[A] (3) ----[C] 720 MB SCSI Drive (Hitachi) In the unsuccessful configuration, the error messages and symptoms were exactly the same as you describe above. I can't say if these are the only reasons for such errors, but you just may want to try changing the order of your SCSI configuration. Remember, also, that both configurations are NOT SUPPORTED by IBM, if you have internal SCSI drives on the same SCSI controller. And, as always, your results may vary ... :^) Alan Stebbens Computer Resource Manager Center for Computational Sciences and Engineering (CCSE) University of California, Santa Barbara 3111 Engineering I Santa Barbara, CA 93106 Internet: aks@hub.ucsb.edu BITNET: aks%hub@ucsbuxa.bitnet UUCP: ...{ucbvax,sdcsvax,cepu}!ucsbcsl!aks Voice: (805) 893-8135 (CCSE Office: 893-3221) -- Alan Stebbens