Ram and Swap monitoring

[Information Systems]

Greetings,
On HP9000 (RP5400 2-CPU, HP-UX 11.11) How/what do I monitor to determin if swap activity is excessive and RAM is low?

Thanks
Mike

[Ken Hubnik_2]

Use swapinfo, top, or glance

[Steven E. Protter]

start with swapinfo

Then run the attached scripts for a reasonable time period and look at the output. If you hae glance you can look at things graphically, buy the attached scripts, which were sent to me by HP Support and are tested let you collect data and look at it later.

Pretty slick.

[Information Systems]

Thanks for the replys, what I am really looking for is some guidance on interpreting the data. Are there any tuning guides for HP platforms. Does anyone have any 'rules of thumb' they could offer? swapinfo -t indicates that the total is 61% used, but I don't know if that is bad or good.

Thanks
Mike

[Marco Santerre]

One rule of thumb that was given to me a while back from HP consultants was that if any of your swap located on disk was totaling more than 5%, that it was bad as you could start having a decreased performance on your system as this value increases.

[MANOJ SRIVASTAVA]

Hi Mike

You may like to see the o/p in thsi form :



Memory Stat total used avail %used
physical 4096.0 724.4 3371.6 18%
active virtual 200.1 34.4 165.7 17%
active real 110.3 33.1 77.2 30%
memory swap 3148.6 119.9 3028.6 4%
device swap 1024.0 284.2 739.8 28%


I got a cscript in the forums which can be easliy compiled and run whever you want to . I am atachignt he script


Manoj Srivastava

[Sridhar Bhaskarla · Accepted solution]

Hi Mike,

The total of 61% includes reservation policy and does not necessarily mean that you are swapping.

Do a swapinfo and ignore the memory entry. If the entries other than memory show some percentage (means in kb USED) means there was some page out activity. The total figure in swapinfo -t tells you how much virtual memory you have on the system and may not necessarily mean that memory consumption is high.

Glance/gpm can give you good stats. If you don't have them, then vmstat is the next default tool that can allow you to monitor the memory.

Do a "vmstat 2 20" and observe and free column. Multiply with 4k and you will get the free memory in MB. Compare it with what you have on the system.

Look at po column. As long as it is low (<10) means you are ok. If it is constantly > 10 and if your free mem is less, then your system is bottlenecking on memory. This in conjection with swapinfo will help you determine the memory resources.

-Sri