Disk size limits in VMS 5.4-1?

From: Chuck McManis <cmcmanis_at_mcmanis.com>
Date: Sat Feb 5 00:45:14 2000

I have a very perplexing problem. What I want to do is mount a Seagate
ST410800N on a VMS 5.4-1 system.

The hardware is a VAX 4000/300 with an Emulex UC-08-III controller half of
which is in MSCP mode. (the other half is talking to the tape drive) There
are two existing 1GB (Imprimis) drives on this system.

First attempt:

        Put the drive into the SCSI chain, terminate it correctly, drives are
targets 0, 1, and 2. The new drive is now target 0, the others are moved to
1 and 2. I reset the VAX and get into the Emulex firmware (rev 'M' (changed
to 'R' later, see below)) and try to autoconfigure the drives. The two 1GB
drives show up like they should, the 9GB drive shows up as a 500MB drive.
Weird.

Second attempt:
        Replace the firmware in the Emulex with version 'R'. Attempt to
reconfigure, same problem as #1.

Third attempt:
        Attempt to manually specify the geometry and notice that the Seagate is
reporting it has 4925 cylinders but the prompt says the number has to be
between 20 and 4095. I enter a number smaller than 4095 and say 'OK'. Now
the drive shows up as having 14x10E6 blocks! Ok so now we're getting
somewhere but I forgot to configure the other two.

Fourth Attempt:
        Recompute "Fake" heads/sectors numbers so that by using 4094 cylinders I
get close to the drives 17,845,431 blocks. Configure the two 1GB drives
with all the defaults. Seagate drive shows up as a 1/2 G drive again. On a
whim I subtract the number of blocks shown from what it should be, the
result is in the 16x10E6 range, aha! I say.

Fifth Attempt:
        Recompute cylinder/sector/head numbers so that the total will be less than
2^24-1 blocks. This works and I end up with a controller that thinks the
drive is about 8GB in size (I could live with this for now...). So we go
all the way up to VMS.

In VMS I type 'INIT DUA0: TEST' and it fails with "%INIT-F-CLUSTER
unsuitable cluster factor", I drill down through the help files but there
doesn't seem to be a comment on this. It talks about VAX clusters and
CLUSTER_SIZE which I tried setting to higher numbers (like 10 or 16). But
nothing has worked so far.

My questions then are:
        1) Is there a way to get the Emulex controller to recognize more that 2^24
           blocks on a SCSI drive?
        2) Does VMS have a volume size limit in 5.4-1 that I need to know about?
        3) If I "split" the volume on the Emulex into two logical drives, can the sum
           of the logical drive sizes be greater than 8GB?

Curious minds want to know!
--Chuck (Who is enjoying VMS for the time being ... ;-))
Received on Sat Feb 05 2000 - 00:45:14 GMT