Performance question

[nyck]

Hello,

What is the best way to track down the process using the largest residential memory?

The server in question is running RH5.5 Enterprise Edition.

 

[Noway2]

Try the TOP command. It will show you the PID, user, amount of CPU utilization, memory usage, and more.

 

[cyberspace]

I agree with Noway2. A handy tip - when top is running, holding shift and pressing the m key will sort by memory usage - highest first.

'When all else fails.......read the manual'

 

[Annihilannic]

Or:

ps -eo pid,rss,args | sort -n -k 2,2 | tail

Annihilannic.

 

[nyck]

There still seems to be an issue on this server:-

free -m
total used free shared buffers cached
Mem: 257936 210696 47239 0 909 202603
-/+ buffers/cache: 7183 250752
Swap: 39999 0 39999


it seems to think its using 210GB of ram, but nothing is appearing in top or ps.

Any suggestions?

 

[Noway2]

If you are getting no output from either of these commands I would try running them with admin privileges. Try prefixing the commands with sudo, which will ask for your (user) password. Of course your user ID will need to be allowed this capability, but it is better than running applications as the root user.

 

[nyck]

Hello,

sorry my wording, I'm getting output as I'm running as root but there was nothing using silly amounts of memory. The biggest was 1.5GB.

Basically there is 200GB of memory cached which is needed when a program requires it so I have no issue I believe. Does this make sense?

Trust Linux to be different from Solaris

 

[Annihilannic]

That's correct. To assess your server's health you should look at this line, which treats the memory in 'cached' as free memory, which it is effectively because it will be released immediately if required:

             total       used       free     shared    buffers     cached
-/+ buffers/cache:       7183     250752

Annihilannic.