How to reduce RAM consumption when my server is idle
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by Julien Genestoux
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Published on 2010-04-06T09:56:32Z
Indexed on
2010/04/06
10:03 UTC
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Hit count: 390
Filed under:
memory-usage
|free
We use Slicehost, with 512MB instances. We run Ubuntu 9.10 on them. I installed a few packages, and I'm now trying to optimize RAM consumption before running anything on there.
A simple ps gives me the list of running processes :
# ps faux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 2 0.0 0.0 0 0 ? S< Jan04 0:00 [kthreadd]
root 3 0.0 0.0 0 0 ? S< Jan04 0:15 \_ [migration/0]
root 4 0.0 0.0 0 0 ? S< Jan04 0:01 \_ [ksoftirqd/0]
root 5 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [watchdog/0]
root 6 0.0 0.0 0 0 ? S< Jan04 0:04 \_ [events/0]
root 7 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [cpuset]
root 8 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [khelper]
root 9 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [async/mgr]
root 10 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xenwatch]
root 11 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xenbus]
root 13 0.0 0.0 0 0 ? S< Jan04 0:02 \_ [migration/1]
root 14 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [ksoftirqd/1]
root 15 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [watchdog/1]
root 16 0.0 0.0 0 0 ? S< Jan04 0:07 \_ [events/1]
root 17 0.0 0.0 0 0 ? S< Jan04 0:02 \_ [migration/2]
root 18 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [ksoftirqd/2]
root 19 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [watchdog/2]
root 20 0.0 0.0 0 0 ? R< Jan04 0:07 \_ [events/2]
root 21 0.0 0.0 0 0 ? S< Jan04 0:04 \_ [migration/3]
root 22 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [ksoftirqd/3]
root 23 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [watchdog/3]
root 24 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [events/3]
root 25 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kintegrityd/0]
root 26 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kintegrityd/1]
root 27 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kintegrityd/2]
root 28 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kintegrityd/3]
root 29 0.0 0.0 0 0 ? S< Jan04 0:01 \_ [kblockd/0]
root 30 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kblockd/1]
root 31 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kblockd/2]
root 32 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kblockd/3]
root 33 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kseriod]
root 34 0.0 0.0 0 0 ? S Jan04 0:00 \_ [khungtaskd]
root 35 0.0 0.0 0 0 ? S Jan04 0:05 \_ [pdflush]
root 36 0.0 0.0 0 0 ? S Jan04 0:06 \_ [pdflush]
root 37 0.0 0.0 0 0 ? S< Jan04 1:02 \_ [kswapd0]
root 38 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [aio/0]
root 39 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [aio/1]
root 40 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [aio/2]
root 41 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [aio/3]
root 42 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [jfsIO]
root 43 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [jfsCommit]
root 44 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [jfsCommit]
root 45 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [jfsCommit]
root 46 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [jfsCommit]
root 47 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [jfsSync]
root 48 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfs_mru_cache]
root 49 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfslogd/0]
root 50 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfslogd/1]
root 51 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfslogd/2]
root 52 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfslogd/3]
root 53 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsdatad/0]
root 54 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsdatad/1]
root 55 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsdatad/2]
root 56 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsdatad/3]
root 57 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsconvertd/0]
root 58 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsconvertd/1]
root 59 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsconvertd/2]
root 60 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [xfsconvertd/3]
root 61 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [glock_workqueue]
root 62 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [glock_workqueue]
root 63 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [glock_workqueue]
root 64 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [glock_workqueue]
root 65 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [delete_workqueu]
root 66 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [delete_workqueu]
root 67 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [delete_workqueu]
root 68 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [delete_workqueu]
root 69 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kslowd]
root 70 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kslowd]
root 71 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [crypto/0]
root 72 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [crypto/1]
root 73 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [crypto/2]
root 74 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [crypto/3]
root 77 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [net_accel/0]
root 78 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [net_accel/1]
root 79 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [net_accel/2]
root 80 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [net_accel/3]
root 81 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [sfc_netfront/0]
root 82 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [sfc_netfront/1]
root 83 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [sfc_netfront/2]
root 84 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [sfc_netfront/3]
root 310 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [kstriped]
root 315 0.0 0.0 0 0 ? S< Jan04 0:00 \_ [ksnapd]
root 1452 0.0 0.0 0 0 ? S< Jan04 4:31 \_ [kjournald]
root 1 0.0 0.1 19292 948 ? Ss Jan04 0:15 /sbin/init
root 1545 0.0 0.1 13164 1064 ? S Jan04 0:00 upstart-udev-bridge --daemon
root 1547 0.0 0.1 17196 996 ? S<s Jan04 0:00 udevd --daemon
root 1728 0.0 0.2 20284 1468 ? S< Jan04 0:00 \_ udevd --daemon
root 1729 0.0 0.1 17192 792 ? S< Jan04 0:00 \_ udevd --daemon
root 1881 0.0 0.0 8192 152 ? Ss Jan04 0:00 dd bs=1 if=/proc/kmsg of=/var/run/rsyslog/kmsg
syslog 1884 0.0 0.2 185252 1200 ? Sl Jan04 1:00 rsyslogd -c4
103 1894 0.0 0.1 23328 700 ? Ss Jan04 1:08 dbus-daemon --system --fork
root 2046 0.0 0.0 136 32 ? Ss Jan04 4:05 runsvdir -P /etc/service log: gems/custom_require.rb:31:in `require'??from /mnt/app/superfeedr-firehoser/current/script/component:52?/opt/ruby-enterprise/lib/ruby/si
root 2055 0.0 0.0 112 32 ? Ss Jan04 0:00 \_ runsv chef-client
root 2060 0.0 0.0 132 40 ? S Jan04 0:02 | \_ svlogd -tt ./main
root 2056 0.0 0.0 112 28 ? Ss Jan04 0:20 \_ runsv superfeedr-firehoser_2
root 2059 0.0 0.0 132 40 ? S Jan04 0:29 | \_ svlogd /var/log/superfeedr-firehoser_2
root 2057 0.0 0.0 112 28 ? Ss Jan04 0:20 \_ runsv superfeedr-firehoser_1
root 2062 0.0 0.0 132 44 ? S Jan04 0:26 \_ svlogd /var/log/superfeedr-firehoser_1
root 2058 0.0 0.0 18708 316 ? Ss Jan04 0:01 cron
root 2095 0.0 0.1 49072 764 ? Ss Jan04 0:06 /usr/sbin/sshd
root 9832 0.0 0.5 78916 3500 ? Ss 00:37 0:00 \_ sshd: root@pts/0
root 9846 0.0 0.3 17900 2036 pts/0 Ss 00:37 0:00 \_ -bash
root 10132 0.0 0.1 15020 1064 pts/0 R+ 09:51 0:00 \_ ps faux
root 2180 0.0 0.0 5988 140 tty1 Ss+ Jan04 0:00 /sbin/getty -8 38400 tty1
root 27610 0.0 1.4 47060 8436 ? S Apr04 2:21 python /usr/sbin/denyhosts --daemon --purge --config=/etc/denyhosts.conf --config=/etc/denyhosts.conf
root 22640 0.0 0.7 119244 4164 ? Ssl Apr05 0:05 /usr/sbin/console-kit-daemon
root 10113 0.0 0.0 3904 316 ? Ss 09:46 0:00 /usr/sbin/collectdmon -P /var/run/collectdmon.pid -- -C /etc/collectd/collectd.conf
root 10114 0.0 0.2 201084 1464 ? Sl 09:46 0:00 \_ collectd -C /etc/collectd/collectd.conf -f
As you can see there is nothing serious here. If I sum up the RSS line on all this, I get the following :
# ps -aeo rss | awk '{sum+=$1} END {print sum}'
30096
Which makes sense.
However, I have a pretty big surprise when I do a free:
# free
total used free shared buffers cached
Mem: 591180 343684 247496 0 25432 161256
-/+ buffers/cache: 156996 434184
Swap: 1048568 0 1048568
As you can see 60% of the available memory is already consumed... which leaves me with only 40% to run my own applications if I want to avoid swapping. Quite disapointing!
2 questions arise :
- Where is all this memory?
- How to take some of it back for my own apps?
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