problem with swap

[leoni]

i (sorry for my bad english, i'm french)
i have a problem with a swap partition on vg00/lvol2 i want to increase size....but i can't do it with sam....it doesn't work. how can i increase it ?? also in swapinfo, i can see that all the capacity of my swap partition is reserved ! what is the parameter i have to change ? i'm on version 10.20.....tx a lot

[Brian M. Fisher]

If you need to add more swap space on a live system, either use a unused logical volume/disk or create a swap file. Both can be done through SAM

Brian
<*(((>< er

[Alan Riggs]

You have a couple of issues.

First: swap space must be contiguous. That is why it is not generally possible to increase the size of your primary swap partition without a full system rebuild. The general solution is to create a new logical volume and activate it as swap. This volume must be created contiguous and without bad block relocation. (lvcreate -C Y -r n). You can activate it manually with the swapon command, or set it to activate automatically by including it in /etc/fstab. (man fstab will show you the appropriate flags.)

HP-UX reserves space to page out a process as soon as the process begins. What you are seeing in swapinfo is a reflection of this. Reserved space is not "in use", but it cannot be allocated to another process. It is "reserved". This can cause a problem if your swap space is low, because new processes will not be able to fork unless the system can reserve space to page them as needed. (This is called early paging, which increases performance but also increases reuired swap space. To the best of my knowledge, it is not possible to tell HP-UX to adopt a late paging strategy.)

[Robert Gamble]

Adding secondary swap can help alleviate an immediate problem. But the only way to increase primary swap is to rebuild the system. I have done this before using Ignite-UX. Ignite-UX will allow you to keep all your current parameters, users, printers, etc, but you will have 3-6 hours downtime while you perform the reload.

Hope this helped, Good Luck!

[Bernadette Keohan]

Hi Leoni,

I've published an article "Breaking Out Root" in the October issue of Interex. I think it may help you with your swap problem. Ignite-UX is a wonderful tool to help resize root partitions. Feel free to follows the steps outlined in the attached document to resize lvol2.

Hope this helps,
Bernie

[Nikhil Chaudhari]

Hi

leoni

I can define swap of four ways

1> Primary
2> secondary
3> device
4> file system

where Primary you can define at the time of installation and that is also other than root parttion but on the same disk

secondary you can define afterwords and on the second disk.

device is nothing but a total disk or a logical volume

file system is create a file system and used total to be as swap.

Now what you have dfined is device swap.
If you seen the priority then you can define swap from 0 to 9 and that is called highest to lowest priority.

you can define other swap system in your hp and give the priority so that it will not affect on your processes.

regards

Nikhil

[CHRIS_ANORUO]

To the 1st question, create another swap disk on vg00 through SAM you can call it /vg00/swap.
To the 2nd question modify the kernel parameters as follows:
allocate_fs_swapmap=0
swapmem_on=1
This will give you upto 2.75Gb or shared memory for a 10.20.