Computer halts...what can I do?

Question

Hello guys,
I need your precious help. 4-5 times the day my system goes very slowly for some minutes, it almost halts and cant even move the mouse. There is no proof that it happens when I do "heavy jobs" because it has happened even when was editing a doc file. Also I have only the neccessary apps running in the background(even kmail is disabled), and disabled nepomuk indexing. And I dont know what do...
My machine has a disk of 60GB storage(ide), 1gb ram, Intel Celeron CPU 2.40GHz and Nvidia 7xxx series(AGP). I use nvidia drivers and have direct rendering enabled and run kde 4.7.4. Also,hdparm gives me the following results.
<<sudo hdparm -t /dev/sdb3
/dev/sdb3:
Timing buffered disk reads: 152 MB in  3.04 seconds =  49.97 MB/sec
>>
I have and a dmesg log after one halt, yesterday. If you think it will help, tell me to uploaded :)
Any help appreciated.

Answer 1

Hello, sorry for the big delay. I didnt manage to see free -m output but iotop gives me kswapd.
The command above gives the following results:
<<
iotop -qqqo -n10
1008 be/4 periklis    0.00 B/s  466.80 K/s  0.00 %  1.12 % mysqld --defaults-file=/home/periklis/.local/share/akonadi//mysql.conf --datadir=/home/periklis/.local/share/akonadi/db_data/ --socket=/home/periklis/.local/share/akonadi/socket-p/mysql.socket
  330 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.39 % [kjournald]
  987 be/4 periklis    0.00 B/s  222.28 K/s  0.00 %  0.00 % mysqld --defaults-file=/home/periklis/.local/share/akonadi//mysql.conf --datadir=/home/periklis/.local/share/akonadi/db_data/ --socket=/home/periklis/.local/share/akonadi/socket-p/mysql.socket
  988 be/4 periklis    0.00 B/s   44.46 K/s  0.00 %  0.00 % mysqld --defaults-file=/home/periklis/.local/share/akonadi//mysql.conf --datadir=/home/periklis/.local/share/akonadi/db_data/ --socket=/home/periklis/.local/share/akonadi/socket-p/mysql.socket
  989 be/4 periklis    0.00 B/s  133.37 K/s  0.00 %  0.00 % mysqld --defaults-file=/home/periklis/.local/share/akonadi//mysql.conf --datadir=/home/periklis/.local/share/akonadi/db_data/ --socket=/home/periklis/.local/share/akonadi/socket-p/mysql.socket
  990 be/4 periklis    0.00 B/s   66.69 K/s  0.00 %  0.00 % mysqld --defaults-file=/home/periklis/.local/share/akonadi//mysql.conf --datadir=/home/periklis/.local/share/akonadi/db_data/ --socket=/home/periklis/.local/share/akonadi/socket-p/mysql.socket
  330 be/4 root        0.00 B/s   14.46 K/s  0.00 % 23.79 % [kjournald]
  982 be/4 periklis    0.00 B/s    2.89 K/s  0.00 %  0.01 % mysqld --defaults-file=/home/periklis/.local/share/akonadi//mysql.conf --datadir=/home/periklis/.local/share/akonadi/db_data/ --socket=/home/periklis/.local/share/akonadi/socket-p/mysql.socket
  148 be/4 root        0.00 B/s    6.35 K/s  0.00 %  2.49 % [kjournald]
1285 be/4 periklis    0.00 B/s    3.10 K/s  0.00 %  0.00 % python2 /usr/libexec/ubuntuone-syncdaemon
>>