ODA How to Confirm if a Disk has been Dropped Using the ASM Alert.log Messages

Asset ID:	1-71-2138915.1
Update Date:	2016-06-08
Keywords:

Solution Type Technical Instruction Sure

Solution 2138915.1 : ODA How to Confirm if a Disk has been Dropped Using the ASM Alert.log Messages

Applies to:

Oracle Database Appliance X5-2 - Version All Versions to All Versions [Release All Releases]
Oracle Database Appliance Software - Version 2.1.0.1 to 12.1.2.6 [Release 2.1 to 12.1]
Information in this document applies to any platform.
ODA, Disk health, ODAVP, ODA maintenance, ODA Storage, ODA disk,

Goal

What methods can detect problems with disks in the ODA ASM alert.logs?

Solution

There are several indicators and messages that will confirm if an ASM disk is having problems.
One critical problem is when an ASM disk has failed or is in the process of failing.
Oakcli and ASM scripts or queries can provide feedback, but using the ALERT.LOG can provide details and a timeline of disk problems.
The ASM alert.log will provide a few different specific messages when a disk has failed:

The easiest method to confirm if a disk has failed is to search your ASM Alert.log for the keyword DROPPED
There are two stages: Warning that the disk will be dropped and confirmation once the disk is dropped.

WARNING: Started Drop Disk Timeout for Disk ....
...(not open) _DROPPED_<someSlot#_<diskgroup>

Example - Preparing to Drop the disk, Timeout messages:
The alert.log will often show a count-down for disks about to be dropped by ASM

WARNING: Started Drop Disk Timeout for Disk 8 (HDD_E0_S15_1554509420P1) in group 1 with a value 12960
...
...
WARNING: Disk 8 (HDD_E0_S15_1554509420P1) in group 1 will be dropped in: (12041) secs on ASM inst 1
...
WARNING: Disk 8 (HDD_E0_S15_1554509420P1) in group 1 will be dropped in: (500) secs on ASM inst 1
...
WARNING: Disk 8 (HDD_E0_S15_1554509420P1) in group 1 will be dropped in: (0) secs on ASM inst 1

Then after a count-down in seconds you will see the disk being dropped , the disk is found as MISSING, then NOT OPEN

WARNING: PST-initiated drop of 1 disk(s) in group 1

ASM appliance found missing disk in slot 15

Example - Confirmation that disk (not open) HDD_ ...

GMON updating for reconfiguration, group 1 at 31 for pid 31, osid 64646
Wed Mar 09 23:49:04 2016

NOTE: cache closing disk 15 of grp 1: (not open) HDD_E0_S15_1554509420P1 << NOT OPEN
Wed Mar 09 23:49:04 2016

Then the disk name HDD... (or SSD) is converted to _DROPPED

Example - _DROPPED_0015

Wed Mar 09 23:59:04 2016
NOTE: cache closing disk 15 of grp 1: (not open) _DROPPED_0015_DATA

Now the disk is completely dropped and de-referenced from ASM :
The disk will show as Failed on the OS at this point

References

<Document 2063028.1> How to Replace an online ODA (Oracle Database Appliance) Shared Storage Disk

References

<NOTE:2063028.1> - How to Replace an online ODA (Oracle Database Appliance) Shared Storage Disk
<NOTE:470211.1> - How To Gather & Backup ASM/ACFS Metadata In A Formatted Manner version 10.1, 10.2, 11.1, 11.2 and 12.1?

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