Troubleshoot Memory usage - Revision history

47.248.0.41: /* Some typical programs memory usage */

47.248.0.41 — Tue, 29 Aug 2006 13:59:15 GMT

Some typical programs memory usage

← Older revision		Revision as of 13:59, 29 August 2006
Line 104:		Line 104:
	Using free -m before & after the program is stopped.		Using free -m before & after the program is stopped.

-	mldonkley 35M (Bittorrent compiled and ip blocking turned off)	+	mldonkley 35M (Bittorrent compiled and ip blocking turned off)
-	apache ??	+	apache ??
-	mysql 14M	+	mysql 14M
-	lighttpd with php, when Idle = 2M	+	lighttpd with php, when Idle = 2M
-	ddclient 4M	+	ddclient 4M
-	vnc 3M	+	vnc 3M
-	webmin 3M	+	webmin 3M
-	samba 2M	+	samba 2M
-	nut 1M	+	nut 1M

206.248.129.62: Add a typical memory usage table

206.248.129.62 — Thu, 24 Aug 2006 20:23:22 GMT

Add a typical memory usage table

← Older revision		Revision as of 20:23, 24 August 2006
Line 100:		Line 100:

	The si (swap in) and so (swap out) columns show if you have been swapping (i.e. needing to dip into 'virtual' memory) in order to run your server's applications. The si/so numbers should be 0 (or close to it).		The si (swap in) and so (swap out) columns show if you have been swapping (i.e. needing to dip into 'virtual' memory) in order to run your server's applications. The si/so numbers should be 0 (or close to it).
		+
		+	==Some typical programs memory usage==
		+	Using free -m before & after the program is stopped.
		+
		+	mldonkley 35M (Bittorrent compiled and ip blocking turned off)
		+	apache ??
		+	mysql 14M
		+	lighttpd with php, when Idle = 2M
		+	ddclient 4M
		+	vnc 3M
		+	webmin 3M
		+	samba 2M
		+	nut 1M

Flavoie: add command line typed

Flavoie — Thu, 24 Aug 2006 18:47:43 GMT

add command line typed

← Older revision		Revision as of 18:47, 24 August 2006
Line 8:		Line 8:
	This is an example on the HG. Am I really using 124M of RAM ???		This is an example on the HG. Am I really using 124M of RAM ???

		+	LinkStation:/media# top
	top - 11:41:03 up 2:40, 1 user, load average: 0.08, 0.14, 0.15		top - 11:41:03 up 2:40, 1 user, load average: 0.08, 0.14, 0.15
	Tasks: 55 total, 2 running, 53 sleeping, 0 stopped, 0 zombie		Tasks: 55 total, 2 running, 53 sleeping, 0 stopped, 0 zombie

Flavoie: small cosmetic changes

Flavoie — Thu, 24 Aug 2006 18:46:48 GMT

small cosmetic changes

← Older revision		Revision as of 18:46, 24 August 2006
Line 22:		Line 22:

	== free -m ==		== free -m ==
-		+	Any_Linux_box# free -m
	total used free shared buffers cached		total used free shared buffers cached
	Mem: 90 85 4 0 3 34		Mem: 90 85 4 0 3 34

Flavoie: Added Categories

Flavoie — Thu, 24 Aug 2006 18:44:37 GMT

Added Categories

← Older revision		Revision as of 18:44, 24 August 2006
Line 1:		Line 1:
		+	{{Articles\|FAQ\|Debian\|FreeLink\|OpenLink\|General\|HG\|LS1\|LS2\|}}
		+
	= Troubleshooting memory usage =		= Troubleshooting memory usage =

Flavoie: Draft

Flavoie — Thu, 24 Aug 2006 15:54:49 GMT

Draft

New page

= Troubleshooting memory usage =

A better checklist can be found at http://rimuhosting.com/howto/memory.jsp

Running "top" always tells you all RAM is used ?
This is an example on the HG. Am I really using 124M of RAM ???

top - 11:41:03 up 2:40, 1 user, load average: 0.08, 0.14, 0.15
Tasks: 55 total, 2 running, 53 sleeping, 0 stopped, 0 zombie
Cpu(s): 4.3% us, 3.3% sy, 0.0% ni, 89.8% id, 1.6% wa, 0.3% hi, 0.7% si
Mem: 126496k total, 124636k used, 1860k free, 2928k buffers
Swap: 522104k total, 25664k used, 496440k free, 61328k cached

It doesn't tell you the right story, as you'll see below.

== /var/log/messages ==

Look for any "Out of memory" logs.
You should not have any.

== free -m ==

total used free shared buffers cached
Mem: 90 85 4 0 3 34
-/+ buffers/cache: 46 43
Swap: 9 0 9

The top row 'used' (85) value will almost always nearly match the top row mem value (90). Since Linux likes to use any spare memory to cache disk blocks (34).The key figure to look at is the buffers/cache row used value (46). This is how much space your applications are currently using. For best performance, this number should be less than your total (90) memory. To prevent out of memory errors, it needs to be less than the total memory (90) and swap space (9).

== ps aux ==
LinkStation:/media# ps aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.4 2408 580 ? S 09:00 0:01 init [2]
root 2 0.0 0.0 0 0 ? SN 09:00 0:00 [ksoftirqd/0]
root 3 0.0 0.0 0 0 ? S< 09:00 0:00 [events/0]
root 4 0.0 0.0 0 0 ? S< 09:00 0:00 [khelper]
root 5 0.0 0.0 0 0 ? S< 09:00 0:00 [kthread]
root 20 0.0 0.0 0 0 ? S< 09:00 0:00 [kblockd/0]
root 23 0.0 0.0 0 0 ? S< 09:00 0:00 [khubd]
root 56 0.0 0.0 0 0 ? S 09:00 0:00 [pdflush]
root 57 0.0 0.0 0 0 ? S 09:00 0:00 [pdflush]
root 59 0.0 0.0 0 0 ? S< 09:00 0:00 [aio/0]
root 58 0.0 0.0 0 0 ? S 09:00 0:01 [kswapd0]
root 643 0.0 0.0 0 0 ? S< 09:00 0:00 [kseriod]
root 679 0.0 0.0 0 0 ? S 09:00 0:00 [mtdblockd]
root 728 0.0 0.0 0 0 ? S 09:00 0:00 [kjournald]
root 959 0.0 0.0 0 0 ? S 09:00 0:02 [kjournald]
root 1341 0.5 0.1 1812 140 ? Ss 09:00 0:56 /sbin/dhcpcd-bi
root 1497 0.0 0.4 1908 600 ? Ss 09:00 0:00 /sbin/syslogd -
root 1503 0.0 0.2 1796 316 ? Ss 09:00 0:00 /sbin/klogd
root 1509 0.0 0.3 1776 460 ? Ss 09:00 0:00 /usr/sbin/ppc_u
root 1532 0.0 0.1 2184 128 ? S 09:00 0:00 /usr/sbin/ap_se
root 1546 0.0 0.9 3464 1152 ? S 09:00 0:00 /bin/sh /usr/bi
mysql 1607 0.0 8.6 130476 11000 ? Sl 09:00 0:09 /usr/sbin/mysql
root 1608 0.0 0.4 1776 508 ? S 09:00 0:00 logger -p daemo
root 1686 0.0 0.4 2384 520 ? Ss 09:00 0:00 /usr/sbin/dropb
root 1707 0.0 2.2 7632 2848 ? S 09:00 0:03 ddclient - slee
102 1719 0.0 0.4 7088 532 ? Ss 09:01 0:00 /usr/sbin/exim4
root 1725 0.0 0.2 1784 320 ? Ss 09:01 0:00 /usr/sbin/inetd
www-data 1731 0.0 1.0 5956 1328 ? S 09:01 0:00 /usr/sbin/light
www-data 1736 0.0 3.7 17968 4796 ? Ss 09:01 0:00 /usr/bin/php5-c
mldonkey 1742 9.6 28.9 48704 36672 ? Sl 09:01 15:49 /home/mldonkey/
www-data 1760 0.0 1.5 17968 1916 ? S 09:01 0:00 /usr/bin/php5-c
www-data 1761 0.0 1.5 17968 1916 ? S 09:01 0:00 /usr/bin/php5-c
www-data 1762 0.0 1.5 17968 1916 ? S 09:01 0:00 /usr/bin/php5-c
www-data 1763 0.0 1.5 17968 1912 ? S 09:01 0:00 /usr/bin/php5-c
nut 1764 0.0 0.4 2440 568 ? Ss 09:01 0:02 /lib/nut/newhid
nut 1766 0.0 0.3 2292 432 ? Ss 09:01 0:00 /sbin/upsd
root 1768 0.0 0.4 2284 568 ? Ss 09:01 0:00 /sbin/upsmon
nut 1769 0.0 0.4 2284 580 ? S 09:01 0:00 /sbin/upsmon
root 1772 0.0 0.7 7748 968 ? Ss 09:01 0:00 /usr/sbin/nmbd
root 1774 0.0 0.5 11056 744 ? Ss 09:01 0:00 /usr/sbin/smbd
root 1780 0.0 0.3 1776 504 ? Ss 09:01 0:00 /home/myscripts
root 1783 0.0 0.3 1776 500 ? Ss 09:01 0:00 /home/myscripts
root 1786 0.0 0.1 11056 220 ? S 09:01 0:00 /usr/sbin/smbd
root 1797 0.1 1.0 10408 1368 ? S 09:01 0:10 Xvnc :1 -deskto
root 1817 0.0 0.5 5148 676 ? S 09:01 0:00 vncconfig -icon
root 1819 0.0 1.0 8360 1328 ? S 09:01 0:04 x-window-manage
root 1856 0.0 3.2 4504 4092 ? SLs 09:01 0:00 /usr/sbin/ntpd
daemon 1863 0.0 0.2 2452 340 ? Ss 09:01 0:00 /usr/sbin/atd
root 1869 0.0 0.6 2992 780 ? Ss 09:01 0:00 /usr/sbin/cron
root 1886 0.0 0.9 11016 1236 ? Ss 09:01 0:00 /usr/bin/perl /
root 1915 0.0 0.9 11320 1204 ? S 09:44 0:00 /usr/sbin/smbd
root 1917 0.4 2.2 11536 2800 ? S 09:50 0:30 /usr/sbin/smbd
root 1974 0.0 0.8 2860 1024 ? Ss 09:56 0:02 /usr/sbin/dropb
root 1975 0.0 1.4 3544 1812 pts/1 Ss 09:56 0:00 -bash
root 2290 0.0 0.7 2784 992 pts/1 R+ 11:44 0:00 ps aux

The biggest RAM users here are mldonkey & mysql.

== vmstat 1 2 ==
LinkStation:/media# vmstat 1 2
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
3 0 25664 1980 2796 61316 1 3 126 37 186 355 14 4 78 4
0 0 25664 1924 2800 61348 0 0 4 0 155 354 3 2 94 1

The si (swap in) and so (swap out) columns show if you have been swapping (i.e. needing to dip into 'virtual' memory) in order to run your server's applications. The si/so numbers should be 0 (or close to it).