swapinfo - Correct Parameter - Kernel

[cfeitosa]

Hello!

Please, I need a help.

I'm using HP-UX B.11.23 U ia64 with a model ia64 hp server rx2660.

We have 8GB of physical memory and I getting some messages:

"/oracle9i/app/oracle/product/920/backups/monit_arc.sh: cannot fork: no swap space
/oracle9i/app/oracle/product/920/backups/monit_arc.sh: cannot fork: no swap space


/usr/lib/hpux32/dld.so: Cannot map bss for library: mmap(0x0, 0xa128, 0x3, 0x52, -1, 0x0) returns Not enough space."

Our swap space:

u158 /# swapinfo -tan
Kb Kb Kb PCT START/ Kb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 8388608 0 8388608 0% 0 - 1 /dev/vg00/lvol2
dev 8388608 0 8388608 0% 0 - 0 /dev/vg00/lvol10
dev 8388608 0 8388608 0% 0 - 0 /dev/vg00/lvol12
reserve - 4255096 -4255096
total 25165824 4255096 20910728 17% - 0 -

In this moment it's look like good, but I would like to understand why the system isn't using the lvol's swap.

u158 /# swapon -p 1 /dev/vg00/lvol2
swapon: /dev/vg00/lvol2 is already enabled for paging.
u158 /# swapon -p 1 /dev/vg00/lvol10
swapon: /dev/vg00/lvol10 is already enabled for paging.
u158 /# swapon -p 1 /dev/vg00/lvol12
swapon: /dev/vg00/lvol12 is already enabled for paging.

u158 /# kmtune | grep swap
allocate_fs_swapmap 0 Default
dmp_swapdev_is_vol 0 Default
nswapdev 10 Default
nswapfs 10 Default
remote_nfs_swap 0 Default
swapmem_on 0 0
vol_swapdev_is_vol 0 Default

I need to change the "swapmem_on" parameter to 1?

Why theses areas shows kb used = 0??

Please, could someone give me a help?

Thanks!

[Grayh · Accepted solution]

Still Ur system memory utilization 98%, pls check the system kernel parameter for below parameter value:
====================================
dbc_max_pct 50 - 50
====================================
If the value is 50, rearrange new value 8 or 10. After value change, required systems reboot.

After reboot the systems then execute top or glance command, hope fully Ur systems problem will be resolve.

***dbc_max_pct - the maximum percentage of memory to be used by dynamic buffer cache.

Values - Minimum - Maximum - Default
dbc_max_pct 2 - 90 - 50

But HP allows recommended 8 to 10, I have already inform U my previous email.

dbc_max_pct must be greater than or equal to dbc_min_pct.

[cfeitosa]

See...

dbc_max_pct 15 15

[Venkatesh BL]

Hi,

The 'Reserve' value alone shown as USED tells me that the system has not actually PAGED OUT anything from memory yet. This is a good thing!

The device to which a page goes to is not decided till the actual time of page out. So, till that point, the kernel just modifies the 'available swap space' counters to ensure that its usage is within the actual available space.

http://docs.google.com/View?docid=dc7s6mzr_56cgsg9g has some good info.

[Venkatesh BL]

Oops, I missed the first part of the query. The situation looks strange to me. Are you on the latest patch for 11.23? Did the problem go away after changing the dbc values?

[V. Nyga]

Hi,

check this doc:
http://www12.itrc.hp.com/service/cki/docDisplay.do?docId=emr_na-c00904819-7&docLocale=en

Check also your kernel settings as discribed in the doc.

HTH
Volkmar

[V. Nyga]

.. and yes - as the doc says - you should enable pseudo swap with swapmem_on to 1.

V.

[Dennis Handly]

You should also use "swapinfo -tam" so you can get the output in easier to understand Mb.

[cfeitosa]

Hi!

Thanks for all replies.

Patches installed:
u158 /# swlist | grep -i GOLD
u158 /#
u158 /# swlist | grep -i PACK
QPKBASE B.11.23.0712.070a Base Quality Pack Bundle for HP-UX 11i v2, December 2007
u158 /#

The doc that V.Nyga said I can't to access because I don't have privileges. So, please, could someone send me this doc in TXT file?

Thanks

[Dennis Handly]

>The doc that V.Nyga said I can't to access because I don't have privileges. So, please, could someone send me this doc in TXT file?

You must have a support contract to look at it. Sending/posting the document would violate copyright laws.