Apache Tips

This page describes some of the things I have learnt about Apache from using it for four years.

Apache reports out of disk space when not

If Apache refuses to start with one of the following two errors in the error log:

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


 (28)No space left on device: mod_rewrite: could not create rewrite_log_lock Configuration Failed

but you actually haven't run out of disk space, Apache has not shut down properly. It's left a large number of semaphore-arrays, owned by the apache user (which could be

apache, www, nobody

, etc. ) Running

 ipcs -s | grep nobody

shows a long list of these semaphores. To get rid of them:

 ipcs -s | grep nobody | perl -e 'while (<STDIN>) { @a=split(/\s+/); print `ipcrm sem $a[1]`}'

Apache should then start OK.

-- Ian Gibbs