beta: on eqiad mount /srv using labs_lvm

There is no /dev/vdb on eqiad labs, we need to use lvm to create a
partition for us.

/srv is/will be used by git-deploy/Trebuchet/Sartoris..

Change-Id: I6d6670db766c381e8a5915415cfa464445f73e42
Merge "beta: on eqiad mount /srv using labs_lvm" into production