Ruby comes slow after some time after reboot

From time to time, all ruby programs become slow. By slow I mean, they run 2-3x time slower than usually. After restart everything backs to normal. Here are two outputs (first is "slow") from strace -T for process running specs: https://gist.github.com/1213292. Maybe it's not just ruby, but the whole system (which seems more likely), but this is only thing I noticed. It seems to be random, sometimes it happens few times a day and sometimes it's fine for couple of days and every time reboot fixes this. I have neither idea why does time spent in stat grows开发者_StackOverflow社区 that much, nor how to debug it further. Is it system (Ubuntu 11.04) thing, hardware (Intel 320 SSD) problem, something else?

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the stat line also show errors, I'd be worried about hard drives...

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On the typical VPS servers that I use (Slicehost and Linode), the squeaky slice gets the love.

In other words, Ruby/Rails programs can have large working sets. To keep them in memory, I ping every rest interface every 5 minutes (including Ajax rest interfaces). Keeps everything in memory, fresh and toasty warm.

So if by "time to time" you mean after a delay in sequential calls to your service, a pinger may be the answer.