CACHE_ACCEL requested but no suitable object cache is present. You may want to install APC.

Backtrace:

#0 /var/wwwn/w/includes/objectcache/ObjectCache.php(62): ObjectCache::newAccelerator(Array)
#1 /var/wwwn/w/includes/objectcache/ObjectCache.php(50): ObjectCache::newFromParams(Array)
#2 /var/wwwn/w/includes/objectcache/ObjectCache.php(23): ObjectCache::newFromId(3)
#3 /var/wwwn/w/includes/GlobalFunctions.php(3816): ObjectCache::getInstance(3)
#4 /var/wwwn/w/includes/Setup.php(439): wfGetMainCache()
#5 /var/wwwn/w/includes/WebStart.php(157): require_once('/var/wwwn/w/inc...')
#6 /var/wwwn/w/index.php(54): require('/var/wwwn/w/inc...')
#7 {main}