Monitor an ASM rebalance

Command

SELECT group_number, operation, pass, state, power,
       sofar, est_work,
       ROUND(sofar/NULLIF(est_work,0)*100,1) AS pct_done,
       est_minutes
FROM   v$asm_operation
ORDER BY group_number;

What it does

Shows the progress, power and estimated remaining time of ongoing rebalance/resync operations.

When to use it

When tracking whether the rebalance has finished after adding/removing disks.

Caution

Empty result = no active operation (completed). Query only; no risk.