If in the apache error log you are getting this:
(28)No space left on device: AH00023: Couldn't create the ssl-cache mutex
Stop Apache.
Then check if there’s a lot of Apache semaphores by running: ipcs -s
For example:
# ipcs -s ------ Semaphore Arrays -------- key semid owner perms nsems 0x00000000 19398656 apache 600 1 0x00000000 19431425 apache 600 1 0x00000000 15892482 apache 600 1 0x00000000 19464195 apache 600 1 0x00000000 19496964 apache 600 1 0x00000000 45907973 apache 600 1 0x00000000 19529734 apache 600 1 0x00000000 46596103 apache 600 1 0x00000000 46628872 apache 600 1 0x00000000 46661641 apache 600 1 0x00000000 46694410 apache 600 1 0x00000000 46727179 apache 600 1 0x00000000 46759948 apache 600 1 0x00000000 46792717 apache 600 1 0x00000000 47677454 apache 600 1 0x00000000 47710223 apache 600 1 0x00000000 47742992 apache 600 1 0x00000000 47775761 apache 600 1 0x00000000 47808530 apache 600 1 0x00000000 47841299 apache 600 1 0x00000000 47874068 apache 600 1 0x00000000 47972373 apache 600 1 0x00000000 48005142 apache 600 1 0x00000000 48037911 apache 600 1 0x00000000 48070680 apache 600 1 0x00000000 48103449 apache 600 1 0x00000000 48136218 apache 600 1 0x00000000 48168987 apache 600 1 0x00000000 48267292 apache 600 1 0x00000000 48300061 apache 600 1 0x00000000 48332830 apache 600 1 0x00000000 48365599 apache 600 1 0x00000000 48398368 apache 600 1 0x00000000 48431137 apache 600 1 0x00000000 48463906 apache 600 1 0x00000000 11436067 root 666 3 0x00000000 19562532 apache 600 1 0x00000000 19595301 apache 600 1 0xd95b59b9 11599910 root 666 2 0x00000000 20086823 apache 600 1 0x000003d4 11665448 root 644 1 0x00000000 20119593 apache 600 1 0x00000000 20152362 apache 600 1 0x00000000 20185131 apache 600 1 0x00000000 20217900 apache 600 1 0x00000000 20250669 apache 600 1 0x00000000 20283438 apache 600 1 0x00000000 22347823 apache 600 1 0x00000000 22380592 apache 600 1 0x00000000 22413361 apache 600 1 0x00000000 22446130 apache 600 1 0x00000000 22478899 apache 600 1 0x00000000 22511668 apache 600 1 0x00000000 23232565 apache 600 1 0x00000000 25493558 apache 600 1 0x00000000 25526327 apache 600 1 0x00000000 25559096 apache 600 1 0x00000000 25591865 apache 600 1 0x00000000 25624634 apache 600 1 0x00000000 25657403 apache 600 1 0x00000000 25690172 apache 600 1 0x00000000 26574909 apache 600 1 0x00000000 26607678 apache 600 1 0x00000000 26640447 apache 600 1 0x00000000 26673216 apache 600 1 0x00000000 26705985 apache 600 1 0x00000000 26738754 apache 600 1 0x00000000 33620035 apache 600 1 0x00000000 33718340 apache 600 1 0x00000000 33751109 apache 600 1 0x00000000 33783878 apache 600 1 0x00000000 33816647 apache 600 1 0x00000000 33849416 apache 600 1 0x00000000 33882185 apache 600 1 0x00000000 33914954 apache 600 1 0x00000000 34013259 apache 600 1 0x00000000 34046028 apache 600 1 0x00000000 34078797 apache 600 1 0x00000000 34111566 apache 600 1 0x00000000 34144335 apache 600 1 0x00000000 34177104 apache 600 1 0x00000000 34209873 apache 600 1 0x00000000 34308178 apache 600 1 0x00000000 34340947 apache 600 1 0x00000000 34373716 apache 600 1 0x00000000 34406485 apache 600 1 0x00000000 34439254 apache 600 1 0x00000000 34472023 apache 600 1 0x00000000 34504792 apache 600 1 0x00000000 36569177 apache 600 1 0x00000000 36601946 apache 600 1 0x00000000 36634715 apache 600 1 0x00000000 36667484 apache 600 1 0x00000000 36700253 apache 600 1 0x00000000 36733022 apache 600 1 0x00000000 36765791 apache 600 1 0x00000000 37060704 apache 600 1 0x00000000 37093473 apache 600 1 0x00000000 37126242 apache 600 1 0x00000000 37159011 apache 600 1 0x00000000 37191780 apache 600 1 0x00000000 37224549 apache 600 1 0x00000000 37257318 apache 600 1 0x00000000 38731879 apache 600 1 0x00000000 38764648 apache 600 1 0x00000000 38797417 apache 600 1 0x00000000 38830186 apache 600 1 0x00000000 38862955 apache 600 1 0x00000000 38895724 apache 600 1 0x00000000 38928493 apache 600 1 0x00000000 40009838 apache 600 1 0x00000000 40042607 apache 600 1 0x00000000 40075376 apache 600 1 0x00000000 40108145 apache 600 1 0x00000000 40140914 apache 600 1 0x00000000 40173683 apache 600 1 0x00000000 48758900 apache 600 1 0x00000000 48791669 apache 600 1 0x00000000 48824438 apache 600 1 0x00000000 48857207 apache 600 1 0x00000000 48889976 apache 600 1 0x00000000 48922745 apache 600 1 0x00000000 49381498 root 600 1 0x00000000 49414267 root 600 1 0x00000000 49447036 root 600 1 0x00000000 49283197 root 600 1 0x00000000 49217662 root 600 1 0x00000000 49250431 root 600 1
If there are a lot, then run the command below to clear those semaphores out:
# for i in $(ipcs -s | grep 'httpd\|apache\|www-data' | awk '{print $2}'); do ipcrm -s $i; done
Check that they’ve cleared out by running: ipcs -s
Example:
# ipcs -s ------ Semaphore Arrays -------- key semid owner perms nsems 0x00000000 11436067 root 666 3 0xd95b59b9 11599910 root 666 2 0x000003d4 11665448 root 644 1 0x00000000 49381498 root 600 1 0x00000000 49414267 root 600 1 0x00000000 49447036 root 600 1 0x00000000 49283197 root 600 1 0x00000000 49217662 root 600 1 0x00000000 49250431 root 600 1
Then start Apache again.
Violia. Fixed!