Problem: Apache 2.4.6 doesn't start on CentOS 7. error.log shows this confusing error message:
[Mon Mar 16 08:55:03.254104 2026] [core:emerg] [pid 3946] (28)No space left on device: AH00023: Couldn't create the rewrite-map mutex [Mon Mar 16 08:55:03.254178 2026] [:emerg] [pid 3946] AH00020: Configuration Failed, exiting
We don't have problems with free space on storage device, so this message looks really weird:
# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 895M 0 895M 0% /dev tmpfs 920M 105M 815M 12% /run tmpfs 920M 0 920M 0% /sys/fs/cgroup /dev/sda1 50G 14G 36G 28% / # df -i Filesystem Inodes IUsed IFree IUse% Mounted on devtmpfs 228953 296 228657 1% /dev tmpfs 235265 521 234744 1% /run tmpfs 235265 16 235249 1% /sys/fs/cgroup /dev/sda1 14305488 480611 13824877 4% /
# cat /proc/sys/kernel/sem 250 32000 32 128
Solution:
# sysctl -w kernel.sem="250 32000 100 256" kernel.sem = 250 32000 100 256
After that change apache starts normally without complains.
Also some of this apache config-file changes might help:
Mutex fcntl:/var/run/httpd default
or
Mutex flock:/var/run/httpd default
I haven't tested it yet.
0 Responses
Stay in touch with the conversation, subscribe to the RSS feed for comments on this post.
You must be logged in to post a comment.