No space left on device: Couldn't create accept lock

Fixing Apache "No space left on device: Couldn't create accept lock" errors

Error Message: When starting Apache, I get this error message in the main Apache error_log:IXPUB技术博客!^$cGix J

[emerg] (28)No space left on device: Couldn't create accept lock
2?_A L8T0[notice] suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)
)a\_HF7C,I{0[notice] Digest: generating secret for digest authentication ...
9`2t([G.`+L5r'j0[notice] Digest: done
!DM$k`%G;L0[warn] pid file /etc/httpd/run/httpd.pid overwritten -- Unclean shutdown of previous Apache run?
B5T i9V0|],F0[emerg] (28)No space left on device: Couldn't create accept lock

First off, check to make sure that you really aren't out of disk space, or have hit a quota limit. Another way that Apache can create the "accept lock" is with a semaphore. A semaphore is an inter-process communication tool that is used by Apache to communicate with it's child processes. This error message may mean that Apache couldn't create a new semaphore.

Check to see how many semaphores are currently in use. If Apache is running correctly, you should see something like this:

# ipcs -sIXPUB技术博客 T&pCn-cM`_
------ Semaphore Arrays --------
{Ze!w'PU!k0key semid owner perms nsemsIXPUB技术博客8z
yX_A0ay}%H
0x00000000 68681743 apache 600 1IXPUB技术博客IK.wN4k U(h4A:?
0x00000000 68714515 apache 600 1IXPUB技术博客R$~C5}B$W.hQ
0x00000000 68747291 apache 600 1

If Apache is stopped, and you still see these semaphores, then you can safely kill them by running this command for each semaphore id (in the second column)

$ ipcrm -s <semid>

To destroy all semaphores, you can run this from the command line (with "apache" being the apache-user):

for semid in `ipcs -s | grep nobody | cut -f2 -d" "`;IXPUB技术博客a$tz,?y,u

do ipcrm -s $semid; doneIXPUB技术博客G(j"Y-~m

]*{Q3~ ?3x J ]0[这个地方可能需要改一下,我的apache是nobody启的，所以是grep nobodyIXPUB技术博客wz w4FVT"G

IXPUB技术博客$R0{hhEY7s

If you are out of semaphoresIXPUB技术博客 P3Y#Q9U.O#\

If you can't create any more semaphores:IXPUB技术博客#s7S.qqa.]YM

Sometimes your system may need to increase the number of semaphores that are available on the system. This requires a change to a kernel parameter. If you are running on a virtual server and cannot modify kernel parameters, you may need to ask your hosting provider to change this parameter on their host server To view the current parameters:

# ipcs -lIXPUB技术博客C*m!DY*O
------ Shared Memory Limits --------
AUjfjR#kU0max number of segments = 4096
2sb[
g1s0max seg size (kbytes) = 32768IXPUB技术博客otUYm8Zn9Z
max total shared memory (kbytes) = 8388608IXPUB技术博客C.edfV8?u _
min seg size (bytes) = 1IXPUB技术博客.En7Y"}}o8LV0]9Lk
IXPUB技术博客:y9h:njT {S
------ Semaphore Limits --------IXPUB技术博客1nZWn!U2z ~S
max number of arrays = 1024
KY)T2jF2@0max semaphores per array = 250
}VV+@7p0max semaphores system wide = 256000IXPUB技术博客,J$eu5p_@2QH9?
max ops per semop call = 32
w@R6R5~8s0semaphore max value = 32767
u9oT4`@&a0IXPUB技术博客:^ K gZiWuy$~4c
------ Messages: Limits --------IXPUB技术博客c5rKr4^0s @aU#Y
max queues system wide = 1024IXPUB技术博客 @b Q"D$Fg-`
max size of message (bytes) = 8192IXPUB技术博客~5a? YP!}v8H!S$l
default max size of queue (bytes) = 16384

To change these parameters, modify the file /etc/sysctl.conf and add the following lines:IXPUB技术博客4Ep;e'dS8]
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kernel.msgmni = 1024
`)D v3jZ1] ?{/W7q0kernel.sem = 250 256000 32 1024IXPUB技术博客(R&?a1s(H9b*o8\ G

Then load these settings with the command:

这里介绍下kernel.msgmni

/proc/sys/kernel/msgmniIXPUB技术博客#xp#nxI"?$l

该文件指定消息队列标识的最大数目，即系统范围内最大多少个消息队列。IXPUB技术博客G NT
f$e/f
缺省设置：16IXPUB技术博客fHrXpM;HM&m|

在
B J$~0u'te0rootIXPUB技术博客Vp#~y
q"}|;z G~
下用
8nJB6nh#bH0sysctl kernel.msgmniIXPUB技术博客:k"J,hW)V;PG7M8?|
检查该参数，IXPUB技术博客%l9}4?m9y0m;F*hzs5P
也可以在命令行下IXPUB技术博客s#k)rT.jS geF

sysctl -w kernel.msgmni=XXX
I`kIq1},xnb~O0重新设定。IXPUB技术博客C.f2Z5Z"EU

sysctl -p

Your Apache process should now be able to create the needed semaphores and run properlyIXPUB技术博客#b+NgY'c{y

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