[Tue Jun 16 16:17:45.298961 2020] [mpm_prefork:notice] [pid 27988] AH00163: Apache/2.4.34 (Red Hat) PHP/7.1.30 configured -- resuming normal operations
[Tue Jun 16 16:17:45.298991 2020] [core:notice] [pid 27988] AH00094: Command line: '/opt/rh/httpd24/root/usr/sbin/httpd -D FOREGROUND'
[Tue Jun 16 16:23:32.886298 2020] [mpm_prefork:notice] [pid 27988] AH00170: caught SIGWINCH, shutting down gracefully
[Tue Jun 16 16:25:03.152469 2020] [core:emerg] [pid 5264] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 16:35:07.867223 2020] [core:emerg] [pid 11264] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:36:22.761176 2020] [core:emerg] [pid 11501] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:37:27.916628 2020] [core:emerg] [pid 11916] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:40:04.120699 2020] [core:emerg] [pid 13159] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:51:48.633570 2020] [core:emerg] [pid 18177] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:53:07.419691 2020] [core:emerg] [pid 18962] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:55:18.578733 2020] [core:emerg] [pid 19880] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:55:43.130569 2020] [core:emerg] [pid 20112] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
[Tue Jun 16 17:56:43.527864 2020] [core:emerg] [pid 20991] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex
AH00016: Configuration Failed
报错信息如上，可以看到提示的是设备没有足够的空间，但是事实上本地的空间是非常充足的：
[root@test]/opt/rh/httpd24/root/etc/httpd/conf.d# df -TH
文件系统 类型 容量 已用 可用 已用% 挂载点
devtmpfs devtmpfs 34G 0 34G 0% /dev
tmpfs tmpfs 34G 0 34G 0% /dev/shm
tmpfs tmpfs 34G 709k 34G 1% /run
tmpfs tmpfs 34G 0 34G 0% /sys/fs/cgroup
/dev/vda1 ext4 106G 6.1G 95G 7% /
tmpfs tmpfs 6.8G 0 6.8G 0% /run/user/0
/dev/mapper/p4-data ext4 4.3T 1.6T 2.5T 40% /data
tmpfs tmpfs 6.8G 0 6.8G 0% /run/user/1000
这个错误异常往往是因为之前的httpd服务异常关闭或者没有正确重装导致，导致信号量阻塞。我们需要做的就是释放阻塞的信号量。执行下面的命令即可：
for i in `ipcs -s | awk '/httpd/{ next; } {print $2}'`; do (ipcrm -s $i); done
