Recently I notice the memory on my Linux server(CentOS 6.8) is consumed quickly. Yesterday I restart my server, and then use free to check the memory, and it reports about 30GB free among 32GB memory.
However, after one day, the free memory is reduced to 12GB.
Is that normal?
I try to use top -a command and get the following result:
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3083 mysql 20 0 2799m 290m 14m S 6.6 0.9 59:50.83 mysqld
6193 root 20 0 253m 134m 3684 S 0.0 0.4 0:06.62 spamd child
2665 root 20 0 245m 128m 5276 S 0.0 0.4 0:09.47 spamd
6194 root 20 0 245m 125m 1452 S 0.0 0.4 0:00.02 spamd child
18201 datanu5 20 0 520m 93m 14m S 0.0 0.3 0:01.18 php-cgi
19861 datanu5 20 0 517m 91m 15m S 16.3 0.3 0:00.49 php-cgi
1531 root 20 0 1346m 47m 9316 S 0.0 0.1 0:41.05 backup_runner.p
9745 nobody 20 0 2472m 37m 10m S 0.7 0.1 0:27.42 httpd
9492 nobody 20 0 2471m 37m 10m S 0.7 0.1 0:26.90 httpd
9618 nobody 20 0 2535m 37m 10m S 0.7 0.1 0:27.53 httpd
9681 nobody 20 0 2472m 36m 10m S 0.3 0.1 0:27.14 httpd
9556 nobody 20 0 2469m 36m 10m S 0.3 0.1 0:27.74 httpd
19862 datanu5 20 0 461m 33m 13m S 2.3 0.1 0:00.07 php-cgi
2348 root 20 0 160m 28m 2056 S 0.0 0.1 0:06.64 lfd - sleeping
1343 nobody 20 0 2470m 27m 5324 S 0.3 0.1 0:10.38 httpd
3561 root 20 0 109m 25m 6780 S 0.0 0.1 0:16.16 cpsrvd (SSL) -
3213 root 20 0 217m 19m 10m S 0.0 0.1 0:04.93 httpd
3581 root 20 0 54132 13m 2940 S 0.0 0.0 0:00.74 tailwatchd
9491 root 20 0 52316 11m 2344 S 0.0 0.0 0:00.06 leechprotect
9490 nobody 20 0 217m 8844 548 S 0.0 0.0 0:00.00 httpd
3155 mailnull 20 0 77020 8308 4048 S 0.0 0.0 0:00.94 exim
3567 root 20 0 43344 7584 2388 S 0.0 0.0 0:01.36 queueprocd - wa
2622 root 20 0 196m 5632 1444 S 0.0 0.0 0:08.73 snmpd
3875 root 20 0 431m 5312 2496 S 0.0 0.0 0:11.63 dsm_sa_datamgrd
3167 dovenull 20 0 45672 4380 3236 S 0.0 0.0 0:00.33 imap-login
3166 dovenull 20 0 45528 4292 3192 S 0.0 0.0 0:00.96 pop3-login
3162 dovenull 20 0 45520 4240 3200 S 0.0 0.0 0:00.11 pop3-login
...
It seems there are no special process that consume memory a lot, why the free memory is reduced so quickly?
Thank you.
