when running a PHP website on a ocfs2 filesystem, the parse time takes 10 times as long as it was before with ext4. It doesnt matter if ocfs2 is configured for running in primary/primary OR primary/secondary use. Still the same result.
The normal page load time (with ext4) is round about 250ms with ocfs2 it tooks now 1.5 - 2.8 seconds to get the first html response. (no other application is working on the servers, php is the single process which is working on the ocfs2 system)
I have testet mounting it with noatime, but couldn't see any difference. Also PHP is consuming much more cpu time as with ext4.
A normal .html access is done in < 5ms, so read speed has low latence, also a simple copy is done very quick.
cluster size and blocksize is default, also re-format the disc with -T mail; nothing changed. Hope someone can give some hints ;)
switching from php-fcgi to php-fpm solved the problem