The purpose of this article is to illustrate how to add new datastores to be used with existing datastores within the same datacenter and resource pool. For help on migrating between data stores, please read the documentation on Datastore Migration.
Before progressing, during this procedure if the environment is not configured to be Highly Available, then this could cause outages. Please refer to the documentation on High Availability in TAS and/or How TAS Maintains High Availability. Please also check the configuration necessary for each of your tiles to achieve High Availability.
Backup your environment
Check TAS System Health
Tiles
Ops Manager Director
Add the additional datastores
Rebalancing VMs
After you've updated the Bosh Director your Bosh Director will become aware of the added datastores, however Bosh Director will not automatically move VMs to the added datastores. Bosh managed VMs would need to be recreated in order for Bosh to place VMs on the added storage. Furthermore, VMs with persistent disks attached will remain in their existing datastore, Bosh will only move persistent disks to the new datastores if the persistent disks are also recreated.
In conclusion, after adding new datastores existing VMs and Persistent Disks will remain in their current datastores until a recreate occurs; new VMs will take advantage of Bosh's VM Placement algorithm and likely place VMs on the newly added datastores.
How to take advantage of Bosh's VM Placement Logic after adding datastores
***Note these steps will causes apply changes to run longer than usual***
1. Enable VM Recreation (Bosh Director Tile --> Director Config --> Check "Recreate VMs deployed by the BOSH Director" --> Click on "Save")
2. Enable Persistent Disk Recreation (Bosh Director Tile --> Director Config --> Check "Recreate All Persistent Disks" --> Click on "Save")
3. Run an Apply Change on all tiles in which you want their VMs to be rebalanced