Sun Storage 7000 Unified Storage System: High CPU Usage Seen After Drive Goes 'unavail/unknown/removed'

Asset ID:	1-72-1544375.1
Update Date:	2018-01-08
Keywords:

Solution Type Problem Resolution Sure

Solution 1544375.1 : Sun Storage 7000 Unified Storage System: High CPU Usage Seen After Drive Goes 'unavail/unknown/removed' - AK-8000-F0 Event (SAS-1 Only)

Applies to:

Sun Storage 7310 Unified Storage System - Version All Versions to All Versions [Release All Releases]
Sun Storage 7410 Unified Storage System - Version All Versions to All Versions [Release All Releases]
Sun Storage 7210 Unified Storage System - Version All Versions to All Versions [Release All Releases]
Sun Storage 7110 Unified Storage System - Version All Versions to All Versions [Release All Releases]
Information in this document applies to any platform.

Symptoms

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High CPU usage is observed after a drive goes 'unavail', 'unknown' or 'removed'. An FMA "AK-8000-F0" event may be seen - "defect.ak.xmlrpc.hardware.invalid_disk_type"

Note: This issue only affects SAS-1 7x10 Appliances (using the 'mpt' driver).

To verify high CPU usage:

From CLI

status show

From BUI

Click Status
View CPU Util

To verify if a drive is unavailable / unknown state:

From CLI

maintenance problems show

From BUI

Click Maintenance
Click System
Click Problems

Look for an problem indicating "AK-8000-F0" => "The disk 'XXX' uses an interface (SAS) that is incompatible with the enclosure".

TSC NOTE: From a support bundle ::mpt -lv logs from /mpt/mdb.out will show events looping such as these -

1451059: 2013 Apr 2 19:34:21 0 --- 0x3afbfe65 mpt_saspath_fini: entry 21
1451060: 2013 Apr 2 19:34:21 1 --- 0x3afbfe65 mpt_saspath_fini: entry 36
1451061: 2013 Apr 2 19:34:21 0 --- 0x3afbfe65 mpt_saspath_fini: entry 18
1451062: 2013 Apr 2 19:34:21 1 --- 0x3afbfe65 mpt_saspath_fini: entry 39
1451063: 2013 Apr 2 19:34:21 1 --- 0x3afbfe65 mpt_saspath_fini: entry 46
1451064: 2013 Apr 2 19:34:21 1 --- 0x3afbfe65 mpt_saspath_fini: entry 47

Cause

This issue is caused by a known bug in the mpt driver.

BUG 15803237 - SUNBT7183399 Drive logically removed from the pool caused high akd processor uti

Please contact Oracle Support for further information.

Solution

Please perform the following on the effected disk drive -

1. Unseat the effected disk drive.

2. Wait 30 seconds.

3. Reinsert the disk drive.

4. Mark the related problem repaired via the BUI or CLI.

BUI: Maintenance ->Problems -> Click on Problem->Click 'Marked Repaired'
CLI: maintenance problems select <problem-id> markrepaired

5. Confirm the drive comes back into OK state and does not re-fault in maintenance problems after 5 minutes.

6. Check if CPU usage has returned to normal via 'Status'.

If CPU usage is still high and disk has re-faulted please unseat the drive.
If CPU usage now returns to normal with the drive unseated please contact Oracle Support for further assistance.
If CPU usage has returned to normal move to step 7.

TSC should confirm this looks like BUG: 15803237 and if a reseat does not resolve the issue the drive may need to be replaced.

7. If the drive shows no issues after the reseat and remains in an OK state 'and' CPU usage is back to normal levels then the drive will not require replacement.

If you would like to report this issue to Oracle Support Services please open a new Service request.

References

<BUG:15803237> - SUNBT7183399 DRIVE LOGICALLY REMOVED FROM THE POOL CAUSED HIGH AKD PROCESSOR UTI

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