Resizing disks in an existing diskgroup in GCP

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

1. Resize disks from Google Cloud Platform console
   

   Increase all data (not quorum) disks belonging to the same diskgroup to the desired size. Make sure disks in the same diskgroup have the same sizes (except quorum).

2. Run the following on all database nodes as root user:

   # for i in /sys/block/*/device/rescan; do echo 1 > $i; done

3. Check new disk sizes using the following command:

   # flashgrid-dg show -G <dg_name>

   Phys_GiB column must show increased size.

4. Connect to the ASM instance 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.

5. Check new sizes:

   # flashgrid-dg show -G <dg_name>

   Phys_GiB and ASM_GiB should have now same increased size.