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o6R%HGUmB ^

[emerg] (28)No space left on device: Couldn't create accept lock
b#Kb
uHTu/nC0[notice] suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)IXPUB技术博客 RZ-g)gYgej
[notice] Digest: generating secret for digest authentication ...IXPUB技术博客;SpR!C,La*D
[notice] Digest: doneIXPUB技术博客|
F7z#M#Qu!c8_lh,\
[warn] pid file /etc/httpd/run/httpd.pid overwritten -- Unclean shutdown of previous Apache run?
9{phjW,m)j6r^.Q#o0[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.IXPUB技术博客1T t.L#A"R*V;jS,H6wk

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

# ipcs -s
K/z$A0~s9T}0------ Semaphore Arrays --------
z@K*a3`cX
s
Xa0key semid owner perms nsemsIXPUB技术博客w6Y d^.?|;p M
0x00000000 68681743 apache 600 1
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?St$sQ.C00x00000000 68714515 apache 600 1IXPUB技术博客XKg`:T$}yd
0x00000000 68747291 apache 600 1IXPUB技术博客6[c1o*Kf3S F7|

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)IXPUB技术博客YG@uz-k?

$ 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9y9x!K)r`w{6a

do ipcrm -s $semid; doneIXPUB技术博客 IiZ-D cW%BGS

x0y7sI O:y'lu3Z0[这个地方可能需要改一下,我的apache是nobody启的，所以是grep nobody

If you are out of semaphores

If you can't create any more semaphores:IXPUB技术博客|V*Y8bF#v*D

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:IXPUB技术博客zc&gD
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# ipcs -lIXPUB技术博客9E
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------ Shared Memory Limits --------IXPUB技术博客V#xf
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max number of segments = 4096
'b
}#i0L(Y"@3y8j0max seg size (kbytes) = 32768
&_ P%|] uEV?0max total shared memory (kbytes) = 8388608IXPUB技术博客 K?3i qGG@
min seg size (bytes) = 1IXPUB技术博客TNf|6x y
IXPUB技术博客.oEuQo5P |W
------ Semaphore Limits --------
Q;Mnx){4UYU5l0max number of arrays = 1024IXPUB技术博客.h,[^%CQ
w
max semaphores per array = 250IXPUB技术博客M1oo0BnC
max semaphores system wide = 256000
{RdN[F[UF0max ops per semop call = 32IXPUB技术博客~al9v:Qt'l T
semaphore max value = 32767
m\Q1ae2nj?0IXPUB技术博客+D3i/S.D2o%y1p#O/^Pv/C
------ Messages: Limits --------IXPUB技术博客!F+g0f&Y6Ut
max queues system wide = 1024IXPUB技术博客s_0I @,j1x!lb
max size of message (bytes) = 8192
2d:u6m.M H0default max size of queue (bytes) = 16384

To change these parameters, modify the file /etc/sysctl.conf and add the following lines:

kernel.msgmni = 1024IXPUB技术博客g7Dr no
kernel.sem = 250 256000 32 1024IXPUB技术博客!e&b9k Jt8v

Then load these settings with the command:IXPUB技术博客kr8a]&@.{F9fh

这里介绍下kernel.msgmni

/proc/sys/kernel/msgmni

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。
3Pd``.M0缺省设置：16IXPUB技术博客#aI*OB6Z

在IXPUB技术博客9zjGF#n
rootIXPUB技术博客%|O'Dl1{1Et d
下用
%`L/l @*@j/k0sysctl kernel.msgmniIXPUB技术博客rq[CV+h5D
检查该参数，
8bs;F.i}5ED0也可以在命令行下IXPUB技术博客%vRPVWAJC,[D

sysctl -w kernel.msgmni=XXXIXPUB技术博客^$rjcU/L6s*y;s
重新设定。IXPUB技术博客3n"jN{vpS@ a'h(V\

sysctl -p

Your Apache process should now be able to create the needed semaphores and run properlyIXPUB技术博客c(]$nWB

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