Hi all,
I've installed postfix + amavis + clamav + spamassassin for our mailrelay which is checking the spam and virus. It is installed in the machine with capability of 1GB memory. The question is why memory used is not decreasing even thought the amavis doesnt have any process. Below is the detail captured from top command.

11:00 AM

Tasks: 107 total, 1 running, 106 sleeping, 0 stopped, 0 zombie
Cpu(s): 11.7%us, 2.6%sy, 0.0%ni, 80.5%id, 5.1%wa, 0.0%hi, 0.1%si, 0.0%st
Mem: 1036028k total, 443468k used, 592560k free, 65644k buffers
Swap: 2650684k total, 0k used, 2650684k free, 139404k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
5906 amavis 15 0 51960 44m 2480 S 32 4.4 0:00.95 amavisd-new
2610 amavis 15 0 107m 89m 1040 S 14 8.9 0:37.88 clamd
5586 postfix 15 0 5144 2200 1752 S 3 0.2 0:00.30 smtpd
5758 postfix 16 0 4888 1704 1368 S 2 0.2 0:00.08 cleanup



11:10 AM

Tasks: 109 total, 1 running, 108 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.1%us, 0.2%sy, 0.0%ni, 98.4%id, 1.3%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 1036028k total, 460220k used, 575808k free, 66176k buffers
Swap: 2650684k total, 0k used, 2650684k free, 138044k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2308 root 15 0 1624 616 512 S 0 0.1 0:03.49 syslogd
5680 postfix 15 0 4884 1700 1368 S 0 0.2 0:00.09 cleanup
1 root 15 0 1948 652 552 S 0 0.1 0:01.48 init

There are 2 TOP command detail captured which is 11:00 AM and 11:10 AM. It shows that memory used is increasing. This memory will be increasing until it reach maximum 1GB and it will start using SWAP.

The problem is once it reach the maximum, the email will be stuck and mail queue will be increase.

Is there any solution to solve this problem.

TQ

What are the sizes of the amavises process over time? Show ps output, not top.

There is no amavis process in the second top you've cited above. Just because your memory usage is increasing doesn't mean it's related to amavisd.

Having most or all of you memory allocated out to processes isn't uncommon, nor is some swap utilisation.

My worried is i've stopped all application like amavis, postfix, clamd and spamassassin when memory reach maximum. But the problem is memory utilization still not decreasing even thought the application is stopped. I'm not sure whether the memory not decreasing because it reserve for application or it related to LOWMEM setting at kernel.

When i run dmesg i can see that LOWMEM available is 896MB. And if memory utilization is high the LOWFREE at /proc/meminfo is also decreasing. The question is what happen if i add another 3 GB memory. Is it can resolved the issue

There is no evidence that you are running over memory limits. There has been no swap in the data you've shown:

Show the output of the commands that make you believe the system has memory problems; highlight those areas for us to see.