tetranz wrote:
I don't think I had enough swap space. I've increased it to same as memory size.
If your Linode has to use swap for anything other than clearing processes that execute very infrequently out of RAM to make room for more cache, it will slow to a crawl. The symptoms you describe are typical of swap thrashing, where the machine spends all its time moving processes that are actually trying to execute in and out of swap. Check the many threads on this forum for advice on how to tune Apache and MySQL to work within the available RAM. Many default configurations of Apache assume that you have multiple GB of RAM available (as is the case on a physical server) and they need to be altered to work properly on a VPS with limited memory.