[admin@alpha admin]$ /sbin/service httpd start
Starting httpd: /etc/init.d/httpd: ulimit: cannot modify limit: Operation not permitted
Ouch! ap_mm_create(1048576, "/var/run/httpd.mm.18405") failed
Error: MM: mm:core: failed to open semaphore file (Permission denied): OS: No such file or directory
[FAILED]

any idea?

It's trying to modify the ulimit, and apparently can't
Are you on as root (that is "admin" a user number 0 account)?

Additional...
Do a ulimit -a to see the ulimit - from the rest of the error I'd suspect number of open files.

To find your UID, type

id

at the console. If your UID is 0 then it is probably not a permission problem but maybe a kernel configuration problem? If your UID is something other then 0 then it's probably because you don't have permission to access it.

Just as a side note, you really shouldn't have a UID of 0 for the admin user as it opens up more security risks.