Slow server with a lot of swap memory that is not being used
 

Hello,

Our server is very slow but we don't know the problem, also uploading images on that server is a problem and takes a lot of time, can someone give me an indication what could be wrong.

Thx for the advice


$ free -m
total used free shared buffers cached
Mem: 12180 11419 761 0 306 3375
-/+ buffers/cache: 7737 4442
Swap: 23061 0 23061



$ df -m
Filesystem 1M-blocks Used Available Use% Mounted on
/dev/sda1 259 218 28 89% /
tmpfs 6091 0 6091 0% /lib/init/rw
udev 10 1 10 1% /dev
tmpfs 6091 1 6091 1% /dev/shm
/dev/sda10 464 50 390 12% /boot
/dev/sda9 9389 208 8705 3% /home
/dev/sda11 228453 172905 43943 80% /space/devel
/dev/sda8 9389 153 8760 2% /tmp
/dev/sda5 4695 3244 1213 73% /usr
/dev/sda6 2819 640 2036 24% /var

Those all look more or less OK (by the way, it's nice to enclose displays like those in CODE - /CODE blocks, easier to read).

Have you looked at top to see what's going on? Might want to watch that for a while.

Are you getting whacked by attempted break-in's? A useful monitoring tool is ntop which may already be installed on your system or you can get it your distribution's application site; e.g., yum or whatever or you can get it at http://www.ntop.org/ (ntop shows network usage in a way similar to what top does for processes.

You can also use GKrellM which provides a visual display of what's going on on a given server (it can be used across a LAN for multiple servers). See http://members.dslextreme.com/users/...m/gkrellm.html and note that it may already be installed on your server (it is in many distributions). This is a good one for seeing CPU(s) usage, processes graph, disk usage, network usage, memory usage and swap usage (it will also display temperatures and fan information if that's available on your box).

Use one or more of these tools to see what's eating cycles, memory, disk or whatever.

You might want to post system specs -- what's the platform, what's the distribution, what's the hardware, etc.

Hope this helps some.

This is probably an unlikely cause since you are using it as a server but if you have used the hibernate or suspend option since your last reboot this may be the source of your problem. I would use these on my desktop and I would get these same types of problems that showed no cause; memory wasn't affected, the number of processes did not jump, and the cpu usage remained low, my desktop just slowed to a stop, even the clock stopped. My only solution was to stop using those options.

We need much more information. Is the machine shared or dedicated. What else runs besides a web server. Have you tried a download speedtest to test your upstream host's pipes. What is the webserver and which version. Which config options have you enabled or disabled. What framework is the application on the server using.

Without these, it is too much of a moving feast to give any real help.

I would suspect slow I/O. Big wait percentage in top would show if that is the case.
If you use software raid with not so fast disks, it may well be the problem.
M