Resizing disks in an existing diskgroup (on Azure)

This document describes steps required for increasing disk sizes in an existing ASM disk groups.

1. Shutdown the first database node gracefully. See instructions here
2. Resize disks from Azure portal
   

   Increase all data disks belonging to the same diskgroup to the desired size. Make sure disks in the same diskgroup have the same sizes (except quorum).

3. Start the database node
4. Wait until flashgrid-cluster shows cluster status "Good"
5. Repeat steps 1-4 for the other database nodes (no need to increase disks for quorum, it is only necessary for the database nodes)
6. Check new disk sizes using the following command:
   

   # flashgrid-dg show -G <dg_name> 

   Phys_GiB column must show increased size.
7. Connect to the ASM from any database node and run:

   # su - grid
   $ sqlplus / as sysasm
   SQL> ALTER DISKGROUP <dg_name> RESIZE ALL; 

   The above command will resize all disks in the specified diskgroup based on their sizes returned by OS.

8. Check new size:

   # flashgrid-dg show -G <dg_name>

   Phys_GiB and ASM_GiB should have now the same increased size.