recently my server become a little slow and lazy, so I started a small investigation what's going on and found out, that there is some problem with network.
All processes which uses network are able to use 99% of CPU time when they got any requests. First time i thought it's only a bad configured Apache but after some research I found even FTP or SSH does it if they have to do something more (for example getting data to another server using rsync).
So far I wasn't able to find a cause of this. No new software installed, only updated every few days. I have another server which have the same config, same software, same hardware and is updated in same days. But this one works without any problem. I think it's probably hardware (LAN) leaving me to it's creator. Is there some way how can I test if it's really LAN or just something bad happened to the system?
Also there is another issue - maximum speed dropped down to 20-30kB/s for both download or upload.
It's Debian Lenny 2.6.22-6 if you need to know
Thanks for any help