Look for any disks where the header_status is CANDIDATE (instead of MEMBER ) or mode_status is OFFLINE . 3. Check for Ongoing Rebalances
Stay proactive, monitor your disk groups regularly, and your ASM health checker will reward you with silence—the best alert of all.
When it detects a discrepancy—such as a corrupted metadata block, a disk timeout, or an offline disk—it logs a "failure." The "Updated" status usually means the health check engine has refreshed its findings and confirmed that the issue is persistent and requires administrator intervention. Common Causes for This Alert
You can force ASM to verify the consistency of a disk group to see if it clears the error or provides more detail: ALTER DISKGROUP CHECK ALL; Use code with caution. Proactive Tips to Prevent Future Failures asm health checker found 1 new failures updated
To proactively detect such issues, Oracle includes a diagnostic framework known as . For ASM, this manifests as the ASM Health Checker —a set of low‑level diagnostic routines that run automatically in the background. These health checks validate various layers of the ASM instance, including:
A prior error (like an IO error) forced a dismount, triggering this health check finding [Per 2.2.4]. Step-by-Step Resolution Guide 1. Identify the Affected Diskgroup
One disk was lagging, its I/O response times ballooning into the hundreds of milliseconds. Look for any disks where the header_status is
Look for errors like ORA-15080 (synchronous I/O fail), ORA-15195 (disk group corruption), or messages referencing ASM health check failure . 1.2 Identify the Failing Component
: Log into the ASM instance and check if any diskgroups are offline or if disks have been dropped. SQL> select name, state from v$asm_diskgroup;
ASM has internal I/O timers. If a disk consistently fails to respond within a threshold (e.g., _asm_io_timeout ), the health checker marks it as a slow or hanging I/O resource. When it detects a discrepancy—such as a corrupted
Implement these settings to stop recurring health check failures in production.
The ASM health checker does not just detect failures — it .