topic Re: vhand process in Operating System - HP-UX

vhand process

Kennethyap — Mon, 25 Oct 2004 22:48:59 GMT

Dear Experts,
What is the vhand deamon running on UNIX OS ver.11.11 ?
Its grep most of the CPU Utilization.

Thks

Re: vhand process

Tom Ward_1 — Mon, 25 Oct 2004 23:36:27 GMT

Hello,

Vhand is the paging deamon. If it's high in the process list, your system is likely swapping. Check with "swapinfo -tad"

Regards,
Tom

Re: vhand process

bhavin asokan — Mon, 25 Oct 2004 23:46:14 GMT

hi,

vhand is the paging daemon.use glance or vmstat to findout your system is giving large no. of pageouts.if pageouts are more you should have to increase your physical memory.

#vmstat 1 10

check what is coming under pi & po.

regds,

Re: vhand process

Fred Ruffet — Tue, 26 Oct 2004 03:14:47 GMT

Are you using Oracle ?
vhand uses lots of CPU happens when you have an overload of caching (Oracle cache + IO Cache). It may be better decreasing valus for dbc_max_pct and dbc_min_pct HP kernel Parameters, or even better mounting FS for DB files with convosync=direct and mincache=direct options.

Even if you don't use oracle, you can consider first point.

Regards,

Fred

Re: vhand process

Kennethyap — Tue, 26 Oct 2004 04:13:51 GMT

It cause the system hang can't login but can ping the IP. I have to force the server to TOC. How can I check what's the process cause the vhand very high utilization.

Re: vhand process

Fred Ruffet — Tue, 26 Oct 2004 04:22:42 GMT

There's no "one-solution-answer".

You may watch what processes are using lot of memory, but some may have to...

Just tell us :
. Are you using Oracle ?
. What is your dbc_min_pct value ?
. What is your dbc_max_pct value ?
. How many RAM you have ?
. How many swap ?
. If using Oracle, output of ipcs -mb

Regards,

Fred

Re: vhand process

Kennethyap — Tue, 26 Oct 2004 05:02:24 GMT

Are you using Oracle ?
Yes
. What is your dbc_min_pct value ?
5
. What is your dbc_max_pct value ?
15
. How many RAM you have ?
2048MB
. How many swap ?
4096MB
. If using Oracle, output of ipcs -mb

IPC status from /dev/kmem as of Tue Oct 26 17:55:51 2004
T ID KEY MODE OWNER GROUP SEGSZ
Shared Memory:
m 0 0x411c8de2 --rw-rw-rw- root root 348
m 1 0x4e0c0002 --rw-rw-rw- root root 61760
m 2 0x41204f7a --rw-rw-rw- root root 8192
m 4611 0x0c6629c9 --rw-r----- root sys 35121576
m 4 0x06347849 --rw-rw-rw- root root 77384
m 517 0xffffffff --rw-r--rw- root root 22908
m 25606 0x5e1000fc --rw------- root root 512
m 17927 0x18117500 --rw-rw---- oracle dba 129105920
m 8 0x0003235c --rw-rw-rw- rcebmp tcs 291376
m 9 0x0000c062 --rw------- rcebmp tcs 16924
m 10 0x00000000 --rw------- rcebmp tcs 628

Re: vhand process

Kennethyap — Tue, 26 Oct 2004 05:03:59 GMT

Correction...

. How many RAM you have ?
4096MB
. How many swap ?
10240MB

Re: vhand process

Fred Ruffet — Tue, 26 Oct 2004 05:18:12 GMT

Do you have Online JFS installed ? If yes, I would suggest you to re-mount all FS used to store DB files with this options :
convosync=direct,mincache=direct,nodatainlog

Depending on other IOs the server is making, with so much memory, you could consider decreasing dbs_max_pct and dbc_min_pct.
On an Oracle server with 3GB of RAM I have dbc_min_pct/dbc_max_pct are set to respectively 2 and 4. FS for DB files are mounted with options I gave. Server is running fine. Before reducing parameters and setting options, I ran into the same problems you have.

Regards,

Fred

Re: vhand process

Kennethyap — Tue, 26 Oct 2004 05:27:28 GMT

Thks Fred... I will try it....