Balsetcnt, Wsmax et Virtualpagecnt after memory upgrade

[Guillou_2]

Hi,

After a memory upgrade from 128 to 512 on our vax 6000-510 with vms6.2, Autogen refuses to put Balsetcnt to the value indicated in modparams.dat. It lowered Balsetcnt saying that the value in modparams.dat could lead to an unbootable server.

With that low value we now haven't got enough slot and the server does a lot of swap.

I know that there is a relation beetween Vitualpagecnt, Wsmax and Balsetcnt. I think that I need to lower Virtualpagecnt and Wsmaw in order to get enough slot.

How I can estimate the value of these parameters to put them in the modparams and run again Autogen to get an acceptable value for Balsetcnt?

Regards

Steph.

[Jan van den Ende]

Steph,

up until (including) VMS V6, Virtualpagecnt and Balsetcnt were mapped to the same longword, with 28 bits (I believe it was) available for both together.

Starting from V7 they are uncoupled, so maybe you ARE due for an upgrade!

The best you can do under V6 is to have both at a value of 2^x -1 & 2^y - 1, with x+y = 28.

-- If my memory is not exactly correct on the 28 bits, I am sure John will kick in with the correction!


Cheers.

Have one on me.

Jan

[faris_3]

Hi,

1) did you increase the value ?

2) you may consider using virtual balance
set slots :

[OpenVMS VAX V6.0/NF] V6.0 New Features Table Of Contents and Preface

4.12 Virtual Balance Slots......................... 4-15

hth,
/HF

[faris_3]

I forgot the description :

1.1.2.4 Virtual Balance Slots (VBS)

VBS provides a mechanism that gives the appearance of a virtually
unlimited quantity of balance slots by timesharing the set of
memory-resident processes through the limited set of real balance
slots. This new feature will particularly benefit systems that
have a large number of processes resident in memory, either
because of a large number of users (for example, ALL-IN-1), or
because of a large number of processes per user (for example,
Xterminals running DECwindows Motif[R]).

[faris_3]

If you didn't change the value of the parameter, this article may help :

http://h18000.www1.hp.com/support/asktima/operating_systems/CHAMP_SRC940831002547.html

[Guillou_2]

Autogen, after the meory upgrade, sizes itself:
virtualpagecnt from 300000 to 1056576
wsmax from 28700 to 53200
Balsetcnt was lowered to 207 and I would like to get 260.

virtualpagecnt seems to be to high

[faris_3 · Accepted solution]

If the applications worked before the upgrade with virtualpagecnt set to 300000
you can add a max_virtualpagecnt=300000 in
modparams.dat and reexecute AUTOGEN.

If you need more processes with more virtual
space for each, you can enable
virtual balance set slots.

Here an output on a VAX with Virtual Balance Set Slots enabled :

System Memory Resources on 23-NOV-2004 17:56:28.88

Slot Usage (slots): Total Free Resident Swapped
Process Entry Slots 280 0 280 0
Balance Set Slots 150 0 150 0

[Ian Miller.]

add a line in MODPARAMS.DAT seting VIRTUALPAGECNT to the value before the upgrade and re-run autogen. If BALSETCNT value then acceepted consider increasing VIRTUALPAGECNT if you need to. Also look at VBS as that facility was created to address this issue.

[Guillou_2]

I put the value that we used before for virtualpagecnt in modparams and run autogen again.
Now I get the attented value for Balsetcnt.

Thanks all

Steph