Resize ASM disks in AWS (FG enabled cluster)

1. Connect to AWS console https://console.aws.amazon.com
   
2. On the left side -> under the section ELASTIC BLOCK STORE -> choose Volumes
   
3. Choose necessary disk -> click Actions button -> choose Modify Volume -> change Size
   Please note that all data disks (not quorum disk) must be increased under the same diskgroup, otherwise ASM will not let you to have different sized disks.

Choose another data disks and repeat the same steps.

4. Run the following on database nodes via root user:

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

5. Check that disks have correct sizes:

# flashgrid-node

6. Connect to the ASM instance from any database node and run:

[grid@rac1 ~]$ sqlplus / as sysasm
SQL*Plus: Release 19.0.0.0.0 - Production on Fri Aug 23 10:17:50 2019
Version 19.4.0.0.0
Copyright (c) 1982, 2019, Oracle.  All rights reserved.
Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.4.0.0.0

SQL> alter diskgroup GRID resize all; 
Diskgroup altered.