As part of my current research for upcoming setup, I started reading
up on filesystems (was actually looking up fencing which leds to node
crash and file integrity on different fs) to see if there would be any
significant improvement to using a different filesystem for networked
storage. e.g. glusterfs on top of ext4 nodes.
Initially, the reading suggested that ext4 would provide a significant
performance boost. Quite possibly since it delays write longer,
latencies of the network storage is hidden even better especially for
temporary files.
After subsequent reading, it seems that the cost of the massive delay
allocation that could blow up really bad in the event the system
crash.
However, this may also be limited to poorly written applications, i.e.
since some massive arguments last year over Firefox 3.0, sqlite and
ext4 problems, ext4 now detects situations where it should flush to
disk immediately to avoid zero length files on crash.
Assuming I'm using the most likely disk writing applications I'm using
is KVM, exim, dovecot, mysql and postgresql, would ext4 be safe for
production use or should I stick to ext3?
