Removing EBS volumes (FlashGrid Cluster on AWS)

To remove EBS volumes from a running cluster

Determine FlashGrid names of the drives to be removed, e.g. rac2.xvdbb:
```
$ flashgrid-cluster drives
```
If the drives are members of an ASM disk group then drop the drives from the disk group. Example:
```
SQL> alter diskgroup MYDG
    drop disk RAC1$XVDBB
    drop disk RAC2$XVDBB
    rebalance wait;
```

Prepare the disks for removal. Example:

[fg@rac1 ~]$ flashgrid-node stop-target /dev/flashgrid/rac1.xvdbb

[fg@rac2 ~]$ flashgrid-node stop-target /dev/flashgrid/rac2.xvdbb