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In case this question is too subjective/violates any rules of StackOverflow, my apologies.

I have been running processor and memory intensive tasks past 2 weeks. But, even after i stop the run, the system is pathetically slow. A simple operation like opening the terminal by clicking on the icon takes 4 5 seconds. And firefox hangs a lot . I have scp'ed about 60L files from my server ( which is in the next room ) to the local system and it has been running since yesterday morning(30 hours and counting) . How to diagnose what is taking up so much of the available resources that Linux feels worse than Vista ? For now, i cannot restart the system as the scp operation is still running :( I checked System Monitor and it shows CPU1 and CPU2 usage between 20-40% [it keeps fluctuating].

Configuration : 64-bit AMD processor, 2 GB Ram.

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migrated from Jan 18 '11 at 21:29

This question came from our site for professional and enthusiast programmers.

Try – Wooble Jan 18 '11 at 14:14
Will remember that one from next time, did not know that one existed for Ubuntu as well. Cool . – crazyaboutliv Jan 18 '11 at 14:20

The most probable cause is that a lot of memory is swapped after memory intensive operations. Since swap is stored on hard drive, manipulating it slows down a system a lot. The only solution that I know is to turn off swap and then turn it back on (you have to have a superuser permissions):

swapoff -a
swapon -a

However, make sure that you have enough RAM to store all swapped memory there. Otherwise, you can reboot the machine to clean-up swap, or wait until the system will adjust and unswap frequently used memory.

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Yeah, i can't restart the system but i do have superuser powers to do this swap operation. Right now, i have about 400MB of RAM free. Let me see if this can be done. Thanks. – crazyaboutliv Jan 18 '11 at 13:59
I ran top again to see the swap availability and this is what i saw > Total Swap : 4095992k . Used -> 198872k . Free : 3897120k . This means that most of the swap is free ,right ?? – crazyaboutliv Jan 18 '11 at 14:01
@crazyaboutliv: Yes, it means swap is almost not used. What about RAM? – user49531 Jan 18 '11 at 14:10
1931136k total, 1493656k used, 437480k free, 753584k buffers – crazyaboutliv Jan 18 '11 at 14:19

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