topic increase virtual memory in Operating System - HP-UX

increase virtual memory

aruns_s — Sat, 04 Mar 2006 22:44:44 GMT

Hi
How to increase virutal memory in HPUX11.11

regds
Arun

Re: increase virtual memory

Geoff Wild — Sat, 04 Mar 2006 22:49:33 GMT

Try:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=114225

http://docs.hp.com/en/B2355-90950/ch06s03.html

Also:

http://forums1.itrc.hp.com/service/forums/pageList.do?userId=CA1313467&listType=unassigned&forumId=1

http://forums1.itrc.hp.com/service/forums/helptips.do?#28

Rgds...Geoff

Re: increase virtual memory

Senthil Kumar .A_1 — Sat, 04 Mar 2006 23:27:34 GMT

Hi Arun,

By VM ,I think you mean swap. You cannot increase Primary swap per se, because, the swap meeds a contiguos allocation of PE's and usually is LVOL2 in VG00 followed by LVOL3 which is root. So finding a Contiguous PE is mostly unlikely. But, There is a tricky solution to this , if you are interested in creasing "Primary swap" itself, rather than supplementing with the "secondary swap"...

I'm qouting the data here that I was going through which states how to increase the primary swap...

QOUTE"

Increase primary swap.

If you are using logical volumes, you may want to first attempt to extend the disk space allocated for the primary swap logical volume using the lvextend command or SAM. However, you will only succeed if disk space (physical extents) contiguous with the existing swap space is still available, which is unlikely. You must reboot the system for the changes to take effect.

If contiguous disk space is not available, you will need to create a new contiguous logical volume for primary swap within the root volume group, the volume group that contains the root logical volume. You do not need to designate a specific disk. For example:

lvcreate -C y -L 48 -r n -n pswap /dev/vgroot

After creating a logical volume that will be used as primary swap, you will need to use lvlnboot(1M):

lvlnboot -s /dev/vgroot/pswap

"END QUOTE

For more details refer the following link....

http://docs.hp.com/en/B2355-90672/ch06s07.html

regards,
Senthil Kumar .A

Re: increase virtual memory

aruns_s — Sun, 05 Mar 2006 18:16:17 GMT

Hi senthil
Thanks for the reply.
Is there any other way to increase virtual memoty. Adding secondary swap like that

regards
Arun

Re: increase virtual memory

Bill Hassell — Sun, 05 Mar 2006 18:33:51 GMT

There are two ways: create a new logical volume, or use an existing filesystem with some empty space. Either can be done without a reboot -- just use the swapon command. This can be done immediately but the extra swap space will disappear after a reboot. This may be desirable for a one time setting, but to make it permanent, add the swap area to /etc/fstab.

One other note: the maximum number of swapchunks will limit the amount of space you can add. swapchunks is a kernel parameter and when you exceed that value, swapon will give you a warning message that not all of the requested space could be added.

Re: increase virtual memory

aruns_s — Sun, 05 Mar 2006 22:12:36 GMT

Hi Bill
Could u please list out the commmands if i want to create new file system.In that case i may be adding one secondary swap sapce. correct?

Re: increase virtual memory

Bill Hassell — Sun, 05 Mar 2006 23:32:58 GMT

You don't create a filesystem for additional swap space. Pick a filesystem with a lot of extra space such as /var. Use the bdf command to find the free space. In the simplest form, you just type swapon and the mountpoint for the filesystem you want to use. The new swap space is called secondary but other than that, it is just additional swap space.

I did not give a specific example because you need to know how much additional swap space is required, and whether that space is available on a specific filesystem. Also, if you don't specify a limit to the maximum amount of swap space on a filesystem, it could fill up the filesystem and cause other problems. It is much simpler to create a new logical volume and use that as your additional swap space.

Re: increase virtual memory

Senthil Kumar .A_1 — Mon, 06 Mar 2006 00:00:58 GMT

Hi Arun,

ex:

1) creating a myswap LV with 500MB size.

lvcreate -L 500 -n myswap /dev/vg00

2) turn on the swap on the created LV..

swapon /dev/vg00/myswap

Verify by ..

swapinfo -tam

3) to make this swap permanent across boot..add the following line in /etc/fstab file.

/dev/vg00/myswap . swap defaults 0 0

Please note the second entry is "."

Regards,
Senthil Kumar .A

Re: increase virtual memory

aruns_s — Thu, 09 Mar 2006 18:06:19 GMT

Thanks all for the help