Linux - Who uses 485388K memory ?

[Rod]

Linux 7.3
Today memory became less. Why? Who uses 485388K memory ?
Yesterday after boot Linux:
5:13pm up 31 min, 1 user, load average: 2,24, 0,46, 0,17
30 processes: 29 sleeping, 1 running, 0 zombie, 0 stopped
CPU0 states: 0,0% user, 18,0% system, 0,0% nice, 81,0% idle
CPU1 states: 0,0% user, 42,0% system, 0,0% nice, 57,0% idle
Mem: 1031008K av, 93016K used, 937992K free, 0K shrd, 3092K buff
Swap: 1052216K av, 0K used, 1052216K free 21980K cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND
2026 informix 15 0 1044 1044 848 R 0,9 0,1 0:00 top
1 root 16 0 520 520 456 S 0,0 0,0 0:03 init
2 root 15 0 0 0 0 SW 0,0 0,0 0:00 keventd
3 root 34 19 0 0 0 SWN 0,0 0,0 0:02 ksoftirqd_CPU0
4 root 34 19 0 0 0 SWN 0,0 0,0 0:00 ksoftirqd_CPU1
5 root 15 0 0 0 0 SW 0,0 0,0 0:02 kswapd
6 root 15 0 0 0 0 SW 0,0 0,0 0:00 bdflush
7 root 15 0 0 0 0 SW 0,0 0,0 0:00 kupdated
8 root 25 0 0 0 0 SW 0,0 0,0 0:00 mdrecoveryd
14 root 25 0 0 0 0 SW 0,0 0,0 0:00 scsi_eh_0
15 root 25 0 0 0 0 SW 0,0 0,0 0:00 scsi_eh_1
1026 root 15 0 0 0 0 SW 0,0 0,0 0:00 eth0
1102 root 15 0 612 612 512 S 0,0 0,0 0:00 syslogd
1107 root 15 0 476 476 408 S 0,0 0,0 0:00 klogd
1127 rpc 18 0 588 588 496 S 0,0 0,0 0:00 portmap
1225 root 15 0 1284 1284 1156 S 0,0 0,1 0:00 sshd
1324 root 15 0 988 988 768 S 0,0 0,0 0:00 xinetd
1342 root 15 0 704 704 596 S 0,0 0,0 0:00 crond
1349 root 15 0 440 440 380 S 0,0 0,0 0:00 mingetty
1350 root 15 0 440 440 380 S 0,0 0,0 0:00 mingetty
1351 root 15 0 440 440 380 S 0,0 0,0 0:00 mingetty
1352 root 15 0 440 440 380 S 0,0 0,0 0:00 mingetty
1353 root 15 0 440 440 380 S 0,0 0,0 0:00 mingetty
1354 root 15 0 440 440 380 S 0,0 0,0 0:00 mingetty
1363 root 15 0 2224 2224 1740 S 0,0 0,2 0:00 sshd
1364 informix 15 0 1408 1408 1048 S 0,0 0,1 0:00 bash
1613 root 15 0 1572 1568 1172 S 0,0 0,1 0:00 radiusd
1629 root 15 0 2284 2280 1696 S 0,0 0,2 0:00 radiusd
1640 root 15 0 1628 1628 1252 S 0,0 0,1 0:00 calls_ck
1688 informix 15 0 1524 1524 1156 S 0,0 0,1 0:00 stime



But after 1 day work:

4:36pm up 1 day, 2:56, 1 user, load average: 0,41, 0,34, 0,14
30 processes: 29 sleeping, 1 running, 0 zombie, 0 stopped
CPU0 states: 0,0% user, 0,0% system, 0,0% nice, 100,0% idle
CPU1 states: 0,1% user, 0,0% system, 0,0% nice, 99,0% idle
Mem: 1031008K av, 578404K used, 452604K free, 0K shrd, 14440K buff
Swap: 1052216K av, 856K used, 1051360K free 446788K cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND
3537 informix 16 0 1040 1040 848 R 0,9 0,1 0:00 top
1 root 15 0 516 476 452 S 0,0 0,0 0:04 init
2 root 15 0 0 0 0 SW 0,0 0,0 0:00 keventd
3 root 34 19 0 0 0 SWN 0,0 0,0 0:02 ksoftirqd_CPU0
4 root 34 19 0 0 0 SWN 0,0 0,0 0:00 ksoftirqd_CPU1
5 root 15 0 0 0 0 SW 0,0 0,0 0:03 kswapd
6 root 15 0 0 0 0 SW 0,0 0,0 0:00 bdflush
7 root 15 0 0 0 0 SW 0,0 0,0 0:01 kupdated
8 root 25 0 0 0 0 SW 0,0 0,0 0:00 mdrecoveryd
14 root 25 0 0 0 0 SW 0,0 0,0 0:00 scsi_eh_0
15 root 25 0 0 0 0 SW 0,0 0,0 0:00 scsi_eh_1
1029 root 15 0 0 0 0 SW 0,0 0,0 0:00 eth0
1105 root 15 0 612 600 512 S 0,0 0,0 0:00 syslogd
1110 root 15 0 456 392 392 S 0,0 0,0 0:00 klogd
1130 rpc 18 0 544 456 456 S 0,0 0,0 0:00 portmap
1228 root 16 0 1272 1176 1088 S 0,0 0,1 0:00 sshd
1327 root 15 0 948 828 728 S 0,0 0,0 0:00 xinetd
1345 root 15 0 696 628 588 S 0,0 0,0 0:01 crond
1352 root 15 0 432 376 376 S 0,0 0,0 0:00 mingetty
1353 root 15 0 432 376 376 S 0,0 0,0 0:00 mingetty
1354 root 15 0 432 376 376 S 0,0 0,0 0:00 mingetty
1355 root 15 0 432 376 376 S 0,0 0,0 0:00 mingetty
1356 root 15 0 432 376 376 S 0,0 0,0 0:00 mingetty
1357 root 15 0 432 376 376 S 0,0 0,0 0:00 mingetty
1830 informix 15 0 1524 1524 1156 S 0,0 0,1 0:02 stime
1898 root 15 0 2248 2244 1652 S 0,0 0,2 0:02 radiusd
1909 root 15 0 2292 2288 1688 S 0,0 0,2 0:02 radiusd
1911 root 15 0 1628 1628 1252 S 0,0 0,1 0:04 calls_ck
29245 root 15 0 2212 2164 1672 S 0,0 0,2 0:00 sshd
29246 informix 15 0 1388 1388 1036 S 0,0 0,1 0:00 bash

[mjman]

Most of that 'used' ram is cached. This means that it is still available to programs when needed. To figure out how much ram you have available, subtract cached from used.

[Rod]

Where can I find cached memory?

[dylunio]

Rod use the free command in the command line, it will tell you about the cached memory.

free

dylunio

[Rod]

OK
But why Linux work with swap if there is cached memory?


procs memory swap io system cpu
r b w swpd free buff cache si so bi bo in cs us sy id
8 2 1 17412 10724 140636 1771276 0 0 14 18 7 14 7 2 21


10:01pm up 10 days, 12:45, 2 users, load average: 2.45, 1.10, 0.79
111 processes: 107 sleeping, 4 running, 0 zombie, 0 stopped
CPU0 states: 47.0% user, 26.0% system, 0.0% nice, 26.0% idle
CPU1 states: 47.0% user, 25.0% system, 0.0% nice, 27.0% idle
Mem: 2064876K av, 2054148K used, 10728K free, 0K shrd, 134324K buff
Swap: 2097096K av, 17396K used, 2079700K free 1779468K cached

[gwalters]

Cached mem = disk to mem for faster access times
Swap = run out of physical mem and put the mem for proccesses that arent active on the disk (slow) so that apps that need mem can have it.