I have an Ubuntu server running Apache, PHP, Memcache. The problem is that the server hangs for a few seconds every minute or so.
iotop, I see intense disk activity when the server hangs, due to 3 processes:
flush-8 jbd2/sda2-8 jbd2/sda1-8
I haven't been able to understand why I have such activity and how I can prevent that from blocking normal server activity? Any ideas?