what are 'missing' pages?

[Daniel S. Riley]

In article <10426 at cbmvax.commodore.com> grr at cbmvax (George Robbins) writes:
>In article <1963 at naucse.UUCP> sbw at naucse.UUCP (Steve Wampler) writes:
>> The world:
>> 	uVAX-III with 16MB main memory and two 20MB swap partitions
>> 	(not on the internal DEC disks but on two SCSI drives).
>> 	Ultrix 2.2 OS.
[...]
>> Here's the output of 'pstat -s'
>> 
>> 	11661k used (1357k text), 8781k free, 3240k wasted, 40781k missing
>> 	avail: 13*512k 2*256k 3*128k 7*64k 10*32k 12*16k 269*1k
[...]
>1) do you have the second swap area defined in /etc/fstab as a :sw: partition
>	type and have a "swapon -a" comand executed in your /etc/rc?  (or
>	explicitly specified as "swapon /dev/xxnb", I forget when this changed)
>
>2) do you really have two swap areas define in the system configuration file
>	in the "swap on xxnb and xxnb" statement?
[...]

I only have experience with Ultrix 3.x/UWS 2.x on a DS3100, and I'm
still a novice at that, so this may be way wrong.  But anyway...

First check the things George suggested--make sure that 'swapon' and
'fstab' and your kernel configuration are all correct.  If they are,
and vmstat is showing paging on those devices, then here's something
else to check.

It appears that, for paging statistics and such, Ultrix uses the disk
partition sizes hardwired into the kernel (e.g., in scsi_data.c), not
the values read off the pack.  On my DS3100, I've got a 65 meg paging
area on the b partition of a Hewlett-Packard 600-some meg SCSI drive.
The first time I booted the system with that configuration, with the
HP registering as an "UNKNOWN" generic SCSI drive, everything seemed
to work except 'pstat -s' reported 65 meg missing.  I added an entry
to scsi_data.c for the HP with real values for the b partition,
recompiled, rebooted, and 'pstat -s' looked fine.  I don't have sources
handy, so this is purely phenomenological, but it worked for me...

-Dan Riley (riley at tcgould.tn.cornell.edu, cornell!batcomputer!riley)
-Wilson Lab, Cornell University