SUMMARY: Disk Expansion w/ SunOS

From: Todd LeRoy (
Date: Wed Jul 10 1996 - 10:30:33 CDT

A couple weeks ago I posted a query about my disk expansion options. The
original post is as follows:

>I have a SPARC 20 Model 71, running SunOS 4.1.4 (i.e. Solaris 1.something).
>I currently have two internal 1G drives running off of the internal
>SCSI controller, and a FSBE/S controller running an external 2.1G Desktop
>Disk Pack. This system operates as a server (NFS and other services). I
>do NOT have the option to upgrade to Solaris 2.x at this time (although I
>expect to around the end of the year).
>I need to add more disk space (say approximately 4G). I'd like to get the
>best performing disks I can, and allow for future expansion. The problem
>is that many of the options are not supported for SunOS (only Solaris 2.x).
>My first choice is the "4.2GB (2X2.1GB) 7200rpm SCSI-2 MULTIPACK-12 X5511A"
>would give me fast / wide scsi, 7200 RPM, a 12 disk chassis, and throw
>in a fast ethernet as a bonus. The problem is that neither of these are
>supported for SunOS. My questions are as follows:
>1. Sun says that the 5511 (multipack-12) will not function with SunOS. Is
>this true, or will it just not run in wide mode, and be limited to 7 drives
>instead of 12 drives? Will it work, but not be **SUPPORTED**? Are there
>drivers, patches, etc. to make this work?
>2. Will a 5511 work with a FSBE/S card (obviously it would not be running
>in wide mode)?
>3. Will a X1018 work with SunOS (again, in narrow mode)?
>My options as I understand them would be:
>1. If it would work, buy the 5511 and the 1018, run them with SunOS, but
>have them run in narrow mode. When I upgrade to Solaris, then I would
>have the benefits of wide SCSI.
>2. If it would work, buy the 5511 and run it from my FSBE/S controller.
>I would at least have the drive offering the wide ethernet in the future,
>and get 7200 rpm now.
>3. Buy a X5152A and an X5151A (both 2.1GB 7200rpm fast/wide SCSI
>UniPack). One has a 50-68 pin cable, the other has a 68-68 pin cable.
>This is what SunExpress recommends. The downside is non-expandable
>chassis, and maximum of 7 devices/SCSI bus (according to their web pages).
>So, what options do I have? I would prefer to stay with Sun components,
>as I get our service from Sun. Any information on what will actually
>work, other options, experiences, contacts, etc. would be greatly
>appreciated. I will summarize.
>Thanks in advance,
>Todd LeRoy

As expected, I got some good information from sun-managers. Essentially, I
learned the following:

1. SunOS does NOT support wide SCSI devices (or so I have been told).
2. SunOS will work with the the X5511A 4.2G MultiPack. However, you will
    have the following restrictions:
    a. It can only be run in narrow mode. You will need a X903A (or
        similar) cable. You must therefore run with a supported
        fast narrow scsi controller (such as the FSBE/S).
    b. You can't actually fill most of the slots in the X5511A. This
        box has the SCSI IDs hardcoded to individual slots (2-5 and 8-15).
        Because you are limited to a narrow controller, you can only
        address devices through SCSI ID 7. This limits you to the first
        four slots in the X5511A (4 disks totalling 8.4G).
    c. Sun won't be your friend. Their official line is "this is not a
        supported configuration". The fact that it actually works (with
        the above limitations) is irrelevant. NOTE: Don't confuse the
        12 disk 5511 with the 6 disk models. These ARE supported under
        SunOS (but only come with 5400 RPM drives, not 7200).

I have purchased and installed a X5511A (2 - 2.1G 7200 rpm disks) with a
X903A cable. I am currently running it off of my FSBE/S controller, under
SunOS 4.1.4. It appears to work great, but is limited under SunOS to
two more disks (i.e. 4.2G additional space). I am also only getting
narrow SCSI, but that's life.

A big factor in going with the X5511 for me was that we expect to
upgrade (???) to Solaris in the not too distant future. At that time,
I can run wide scsi, and can add more drives (as necessary).

I also got brave and ordered a X1010A fast / wide scsi with fast ethernet
card. I have been told that this will NOT work with SunOS. However,
one day when I'm feeling brave (and have GOOD backups), I would like
to try fooling with this, and see if I can get anything to work. In
particular, I would like to try the following:

1. Can I stuff this in a SunOS box without completely breaking other
    things in the box.
2. Can I at least use the fast ethernet portion of the board? I have
    a need to move to fast ethernet, so this would be handy.
3. Can I get the scsi controller portion of the board to work with
    SunOS in narrow mode? I have read that a X1062A (fast / wide
    differential scsi-2 sbus card) will run under SunOS as a narrow
    card. This raises the questions as to whether other wide scsi
    cards might be able to run under SunOS in narrow mode. Does anybody
    know anything about this?

When (if) I actually try this, I will post an additional summary with
anything else I learn.

One last note: Now that my disks are working, I began the task of trying
to decide how to effectively use the space. The issue is the old
splitting things across partitions problem. I have things that don't
readily split across multiple arbitrary partitions. I would LOVE to be
able to access multiple disks transparently as one file system. I
understand that you can do this under Solaris using DiskSuite. Are
there any solutions for SunOS?

Thanks to Gary Lee, Russ Poffenberger, John Malick (who had actually
run a multipack with SunOS), and especially to Steven Wagner (who
went through the effort of connecting one of these to see if it

Thanks again,


               Todd LeRoy			It is my official opinion
Organization:  Norland Corporation		that I have no opinions...
PHONE:         (414) 563-8456 ext. 215
US Snail:      W6340 Hackbarth Road, Fort Atkinson, WI 53538

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