Thank you very much for your quick responses.
On Wed, Jun 2, 2010 at 5:26 PM, Lennart Sorensen < lsore...@csclub.uwaterloo.ca> wrote: > On Wed, Jun 02, 2010 at 05:06:30PM +0200, Jonatan Soto wrote: > > Hi list, > > > > I'm facing a problem with lenny regarding to memory usage. > > > > I have 4 VM lenny based on top of a VMWare ESXi. The system is running > for a > > few days and top command shows a very high amount of memory consumption > for > > each server. I have a little knowledge of how linux (kernel 2.6) manages > > memory. A nice resource I found is this: > > http://www.linuxhowtos.org/System/Linux%20Memory%20Management.htm > > > > So, I understand that cached memory may be free if some application > requires > > it but I don't understand why lenny is consuming 2GB of physical memory. > > It's worth to mention that all the systems are running with only the > > standard package installed and few additional daemons for each server. > > > > I post what top command shows in order to provide better clues of what's > > going on: > > > > Server1: > > top - 18:47:12 up 12 days, 3:57, 2 users, load average: 0.00, 0.00, > 0.00 > > Tasks: 53 total, 2 running, 51 sleeping, 0 stopped, 0 zombie > > Mem: 3097764k total, 2901684k used, 196080k free, 156460k buffers > > Swap: 578300k total, 0k used, 578300k free, 592736k cached > > additional daemons -> apache2, bind9, sshd > > > > Server2: > > top - 18:48:30 up 12 days, 2:29, 2 users, load average: 0.00, 0.00, > 0.00 > > Tasks: 55 total, 1 running, 54 sleeping, 0 stopped, 0 zombie > > Mem: 3097764k total, 2412008k used, 685756k free, 145204k buffers > > Swap: 915664k total, 0k used, 915664k free, 155112k cached > > additional daemons -> apache2, sshd > > > > Server3: > > top - 18:52:10 up 12 days, 2:32, 2 users, load average: 0.00, 0.00, > 0.00 > > Tasks: 72 total, 1 running, 71 sleeping, 0 stopped, 0 zombie > > Mem: 3097764k total, 2263200k used, 834564k free, 49152k buffers > > Swap: 2928632k total, 0k used, 2928632k free, 107700k cached > > additional daemons -> lvm, sshd > > > > Server4: > > top - 16:50:19 up 1 day, 6:42, 2 users, load average: 0.00, 0.00, 0.00 > > Tasks: 58 total, 1 running, 57 sleeping, 0 stopped, 0 zombie > > Mem: 3097764k total, 272300k used, 2825464k free, 126164k buffers > > Swap: 1341388k total, 0k used, 1341388k free, 53196k cached > > additional daemons -> bind9, sldap, samba, sshd > > > > -------------------- > > > > Note that I've recently rebooted Server4 and it has lower memory > consumption > > rather than the others and it is running more daemons. > > May be this issue is a misconfiguration of my servers or a memory leak? > > Should I tweak something in order to improve memory management? > > > > Any help would be much appreciated. > > > > PD: Apache2 is installed using default configuration of the Apache2 > official > > Debian release. > > Well I would run top, hit 'M' to sort by memory usage, and see which > processes are using the ram. > Well, that's what I did and that's why I decided to consult here because I thought it might be a problem since the memory usage shown in top doesn't match the amount of memory consumption of each process. The following corresponds to Server3, I understand that these processes cannot consume 2GB of physical memory.... 12027 root 20 0 89732 3764 2988 R 0 0.1 0:00.30 sshd 22502 root 20 0 163m 2752 1560 S 0 0.1 0:42.68 nscd 3608 root 20 0 77784 2164 1668 S 0 0.1 0:00.66 login 3009 root 20 0 119m 2080 1004 S 0 0.1 0:20.07 rsyslogd 28878 root 20 0 10576 1768 1312 S 0 0.1 0:00.36 bash 12030 root 20 0 10528 1676 1264 S 0 0.1 0:00.00 bash 3280 root 20 0 23896 1436 1132 S 0 0.0 7:36.22 vmware-guestd 28889 root 20 0 42808 1144 672 S 0 0.0 0:01.12 sshd 1262 root 16 -4 16912 1124 484 S 0 0.0 0:00.04 udevd 12034 root 20 0 10624 1100 848 R 0 0.0 0:04.90 top 3553 Debian-e 20 0 42716 1016 612 S 0 0.0 0:07.40 exim4 3591 root 20 0 19804 844 652 S 0 0.0 0:05.16 cron 2793 statd 20 0 10136 760 632 S 0 0.0 0:00.00 rpc.statd 1 root 20 0 10312 756 620 S 0 0.0 0:11.76 init 3020 root 20 0 3796 600 476 S 0 0.0 0:00.00 acpid 3616 root 20 0 3796 584 484 S 0 0.0 0:00.00 getty 3612 root 20 0 3796 580 484 S 0 0.0 0:00.00 getty 3617 root 20 0 3796 580 484 S 0 0.0 0:00.00 getty 3609 root 20 0 3796 576 484 S 0 0.0 0:00.00 getty 3613 root 20 0 3796 576 484 S 0 0.0 0:00.00 getty 2782 daemon 20 0 8020 536 416 S 0 0.0 0:00.00 portmap 3571 daemon 20 0 16356 444 296 S 0 0.0 0:02.40 atd > > For example: > > top - 11:22:12 up 12 days, 23:25, 11 users, load average: 1.52, 1.51, 1.67 > Tasks: 257 total, 1 running, 256 sleeping, 0 stopped, 0 zombie > Cpu(s): 3.5%us, 0.3%sy, 0.0%ni, 86.4%id, 9.8%wa, 0.0%hi, 0.0%si, > 0.0%st > Mem: 16473836k total, 16311892k used, 161944k free, 5624832k buffers > Swap: 16777208k total, 168k used, 16777040k free, 6619416k cached > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 8998 bacula 20 0 193m 123m 1792 S 28 0.8 1611:17 bacula-dir > 21000 snmp 20 0 41976 34m 980 S 0 0.2 2:30.73 snmpd > 20123 bind 20 0 117m 27m 860 S 0 0.2 0:00.22 named > 20768 mysql 20 0 124m 12m 1060 S 0 0.1 1:26.30 mysqld > 23350 root 20 0 34336 9988 7404 S 0 0.1 0:00.76 bat > 21302 root 20 0 23564 6772 2312 S 0 0.0 0:02.66 apache2 > 8829 root 20 0 44808 5892 1276 S 0 0.0 69:42.16 bacula-fd > 9077 www-data 20 0 23564 5728 1160 S 0 0.0 0:00.39 apache2 > 20085 www-data 20 0 23700 5684 1072 S 0 0.0 0:01.12 apache2 > 22824 www-data 20 0 23564 5684 1120 S 0 0.0 0:00.46 apache2 > 1128 www-data 20 0 23564 5676 1160 S 0 0.0 0:00.34 apache2 > 22821 www-data 20 0 23564 5676 1112 S 0 0.0 0:00.40 apache2 > 9079 www-data 20 0 23564 5672 1108 S 0 0.0 0:01.33 apache2 > 20606 www-data 20 0 23564 5668 1104 S 0 0.0 0:00.39 apache2 > 20468 www-data 20 0 23564 5644 1080 S 0 0.0 0:00.80 apache2 > 20082 www-data 20 0 23564 5640 1072 S 0 0.0 0:00.98 apache2 > 9078 www-data 20 0 23564 5624 1044 S 0 0.0 0:00.61 apache2 > > So in this case my bacula tape backup is using about 200MB, snmpd is > using 34M, bind (named) is using 27M, mysql is using 12M. not much > going on. Lots of apache2 processes each using a bit under 6M. > > The RES is how much is resident in memory. VIRT is the whole process > memory space but that includes shared libraries and memory mapped files > and other things, and not just the memory used. > So I understand there's nothing to worry. I should look at field RES so the sum of all the processes is the correct physical memory usage . Is that right? Another way to see how much memory is consuming the process could be ps -ef, but it's a percentage. Taking this value, probably matches the REST value of top command. Please correct me if I'm wrong. > Of course the kernel can also have network buffers and other things > using some memory, which won't show in top. I do expect in your case > something obvious to be using the memory though. > > -- > Len Sorensen > Thanks again for your valuable help.
