glusterfs setup on c1:
  * for h in c1 c2 c3; do ssh $h sudo mkdir /persist/glusterfs/compute; done
  * gluster peer probe c2
  * gluster peer probe c3
  * gluster volume create compute replica 3 c{1,2,3}:/persist/glusterfs/compute/brick1
  * gluster volume start compute
  * gluster volume bitrot compute enable

glusterfs tweaking for wordpress performance:
  * gluster volume set compute nl-cache on
  * gluster volume set compute features.cache-invalidation on
  * gluster volume set compute features.cache-invalidation-timeout 600
  * gluster volume set compute performance.cache-invalidation on
  * gluster volume set compute performance.qr-cache-timeout 600
  * gluster volume set compute performance.stat-prefetch on
  * gluster volume set compute performance.md-cache-timeout 600
  * gluster volume set compute network.inode-lru-limit 200000
  * gluster volume set compute performance.nl-cache-timeout 600
  * gluster volume set compute performance.parallel-readdir on
  * gluster volume set compute performance.cache-size 1GB
  * gluster volume set compute client.event-threads 8
  * gluster volume set compute server.event-threads 8
  * gluster volume set compute cluster.readdir-optimize on
  * gluster volume set compute server.outstanding-rpc-limit 256

mysql credentials
  * Put secrets/mysql_root_password into a Nomad var named secrets/mysql.root_password

postgres credentials
  * Put secrets/postgres_password into a Nomad var named secrets/postgresql.postgres_password