In ceph-ansible, you can specify a disk to be used for databases in the hosts file using the dedicated_devices directory. Example:
hosts:
stor01.hostname.com
devices: ['/dev/sdd', '/dev/sde', '/dev/sdf']
dedicated_devices: ['/dev/sdc']
Here sdc is an SSD drive which will be used for the rocksdb database. It should be at least 1% of the total size of the hard drives for this to work.
However, what if my OS is already on the SSD drive I intend to use? Let's say that this is a large SSD drive with a small OS partition and several empty partitions, one for each 1TB HDD. E.g. the config is:
/dev/sda
..sda1 40GB ext4 OS (mounted: /)
..sda2 20GB xfs (unmounted)
..sda3 20GB xfs (unmounted)
(etc)
/dev/sdb (unpartitioned, 1TB)
/dev/sdc (unpartitioned, 1TB)
(etc).
Essentially I don't want ansible to go and format the drive, but I do want it to set the already pre-formatted partitions as the location of the db file. How do I achieve this?
