Can Sybase 11 on OpenVMS exceeds 1 GB memory limitation

[allenzhang]

I was told that Sybase 11 on OpenVMS, even 7.3-2, cannot address more than 1 GB memory, related to the old 4 GB memory for s0,s1,p0,p1.

I am going to give it a try very soon, but I wonder any experts already have an answer.

TIA.

Allen

[Hein van den Heuvel]

Back in 1996 Sybase had VLM support for Tru64, but not for OpenVMS best I know.

http://www.hpl.hp.com/hpjournal/dtj/vol8num4/vol8num4art7.pdf
[Moderator note: Removed the broken links.]
Then in 1999 EOL was announced for the OpenVMS offering with 11.0.3.3.
I don't recall VLM support at that point in time, but I'll gladly be proven wrong.



fwiw,

Hein.

[Wim Van den Wyngaert]

The maximum working set under 7.3 is about 4 GB. So, you should keep all the Sybase memory in the working set. If not, you could get a lot of pagefaults.

I would test it but don't have the machine for it.

Wim

[Wim Van den Wyngaert]

http://manuals.sybase.com/onlinebooks/group-asarc/srp1102e/vmsins02/@ebt-link;pt=9639?target=%25N%15_10328_START_RESTART_N%25

Don't see any limitations mentioned in the doc.

Wim

[Hein van den Heuvel]

>> Don't see any limitations mentioned in the doc.


Agreed, but there were none mentioned to Vax either, where the limit was 1GB P0.

The doc on migrating VAX -> Alpha does not mention a vastly increased memory range.

The example numbers in the doc are all about small numbers of MB, up to 120MB or so. No mention of GB sized buffers.

The sp_configure 'total memory' doesn't mention anything, nor 'total data cache size'

fwiw,
Hein.

[Ian Miller.]

As sybase is now opensource I guess you could have a look yourself

http://www.sybase.com/developer

[Craig A Berry]

Ian, where do you get the idea that Sybase is open source? The developer page you point to doesn't say anything about that.

There is an open source replacement for the open client libraries and utilities, and it does work on VMS. See

http://www.freetds.org

But that's a far cry from having the database server open source.

[Ian Miller. · Accepted solution]

My mistake, I was thinking of INGRES for some reason :-(
SYBASE is not opensource.

SYBASE would need changes to use P2 and/or S2
- parhaps they have not done them.

[allenzhang]

Thanks for all the input.

And I doubt Sybase has changed its code to use P2 or S2.

I will still try to increase total memory to 1.2 GB and restart database server and see what's the error message will be.

I will post my findings here.

Allen

[allenzhang]

Hi All,

I tested and it doesn't work.

Here is the error message and it is quite similar to those we got from Linux and Unix box.

00:2006/12/19 10:59:47.83 kernel Warning: Using default file 'SYBASE_SYSTEM:[SY
BASE]SERVER.cfg' since a configuration file was not specified. Specify a configuration file name in the RUNSERVER file to avoid this message.
00:2006/12/19 10:59:47.87 kernel os_create_region: error creating global section
00:2006/12/19 10:59:47.88 kernel %SYSTEM-F-GPTFULL, global page table is full
00:2006/12/19 10:59:47.88 kernel kbcreate: couldn't create kernel region.
00:2006/12/19 10:59:47.89 kernel kistartup: could not create shared memory

Other information on my VMS box
WRITE SYS$OUTPUT f$getsyi("GBLPAGES") and I get 3950000

write SYS$OUTPUT f$getsyi("FREE_GBLPAGES") and I get
677696.

Looks to me there is no workaround at this stage to allow my Sybase server to address over 1 GB space, and I don't think Sybase Inc is going to change their code. Sad....

[allenzhang]

There is no workaround for it. It is highly unlike Sybase will change it code to solve this problem.

[Wim Van den Wyngaert]

I tried it with 1.5 GB (sp_configure "total memory", 750000). I put quotas hight.

Result :
os_create_region: error creating global section
SYSTENM-F_VASFUL virtual address space is full

Then do help/mes VASFUL ...

So, I think you reached another limit. One of your system, not VMS

Wim on 7.3

[Wim Van den Wyngaert]

http://h71000.www7.hp.com/openvms/journal/v5/removing-32-bit-limit.html

If I understand correctly, all Alpha exe's made on pre 7 should go up to 2 GB. But then why did my server crash at 1.5 ?

Wim

[allenzhang]

Thanks Wim.

Wim, could you please tell me what's the current total memory you allocated to Sybase?
Can you give it a try to see if you can configure Sybase with a number greater than 1024 MB? (e.g say 1.2 GB by using sp_configure 'total memory' ,614400).

I am very keen to see if I can exceed 1 GB memory. My system performance will improve a lot if Sybase can access, say 1.5 GB?

Thanks.

Allen