actual device swap usage

[Michael Dalanek]

Is there any way to see the actual device swap usage (reserved) ?

swapinfo always shows 0% used (unless your paging or out of memory in which case its >0), but for all user processes loaded into memory they must reserve some device swap and I want to see how much is reserved. Even glance/gpm does not show this.

[Stefan Farrelly · Accepted solution]

Yes, this is a problem. It would be nice to see actually how much reserved device swap is in use (which shows all programs loaded into memory which arent locked - ie. eligible for actual paging to disk if necessary). The only way ive found to do it is with a C program. Its attached, called memory_detail.c
The output looks like this once youve compiled and run;


Memory Stat total used avail %used
physical 512.0 267.9 244.1 52%
active virtual 34.8 19.0 15.8 55%
active real 38.9 15.6 23.4 40%
memory swap 376.0 142.1 233.9 38%
device swap 512.0 70.5 441.5 14%

This is extremely handy. Now you can see from above I have 70.5 MB of processes loaded into memory which are not locked into memory (like Oracle would be eg.) and eligible for paging to disk if I run out of physical memory.
Memory swap shows me I have 142MB of ram used which is locked - ie. it cant be paged. This includes things like buffer cache, the kernel and its tables, and specific OS daemons which cant be paged out.

[SURI HUNJAN]

Hi michael,

try swapinfo -t.
Normally gives a percentage of total swapspace reserved.

cheers
surinder

[MANOJ SRIVASTAVA]

Hi Michael


You may like to use this small script which tell you about memdetails in the following format :

Memory Stat total used avail %used
physical 32764.0 16544.2 16219.8 50%
active virtual 6304.7 2574.3 3730.4 41%
active real 6986.8 2679.0 4307.8 38%
memory swap 26522.5 11651.0 14871.5 44%
device swap 3332.0 3332.0 0.0 100%


I ahve atached a simple script which I got from the forums which can be comiled and run to get this o/p.


Manoj Srivastava

[MANOJ SRIVASTAVA]

Hi Michael


You may like to use this small script which tell you about memdetails in the following format :

Memory Stat total used avail %used
physical 32764.0 16544.2 16219.8 50%
active virtual 6304.7 2574.3 3730.4 41%
active real 6986.8 2679.0 4307.8 38%
memory swap 26522.5 11651.0 14871.5 44%
device swap 3332.0 3332.0 0.0 100%


I have atached a simple script which I got from the forums which can be comiled and run to get this o/p.


Manoj Srivastava