Paranormalis

I'm using IPB 3.1.2, LiteSpeed and APC (both latest), user online count tops at 1200 on busy periods but is usually between 600-800.

Although there are vast performance improvements with APC enabled (load avg 1-3 instead of 3-10), I'm worried about cache fragmentation and full cache counts. No matter what settings I use, fragmentation builds up and I also get a whole bunch of cache full counts, which is what I want to disappear.

Using cache size = 300 MB, stat = 0, file and user ttl = 0, I get this after a couple hours:

Using bfarber's settings (file ttl=300 and user ttl=180), fragmentation still builds up, although much slower (takes almost a day). Cache full counts, however, shows really high numbers (10000+), reverts to 0, them builds up again to high numbers, reverts to 0, and so on, all in interval of minutes.