APC 15000 RAID User Manual

Controller Management

007-5510-002

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Tier Verify OFF Screen

TIER VERIFY=X A specified tier will be verified if possible.

These API and CLI commands will affect the TIER verification process:

• The CLI commands TIER PAUSE, TIER RESUME, TIER STOP.

• The API command TIER STATUSCHANGE.

LUN operations (add, delete, move) can affect TIER VERIFY operations. As tiers are verified, only 
LUNs that are valid and formatted are verified.

If a tier is owned by the other unit, and it is healthy, the user is notified that the verification cannot occur 
due to the ownership of the tier. The user can then retry the verification on the other unit.

The verification of LUNs on a tier is performed in the order of addressing on the tier. Only valid and 
formatted LUNs can be verified.

The rebuild journaling feature is intended to speed the recovery from disk-side loss of communication 
problems.  A loss of communication includes, but is not limited to, SAS expanders,  hardware/software 
failures, and SAS cable failures, and SFP failures.  

Currently, when the controller encounters a loss of communication with a drive or a group of drives on 
a SAS link, the software fails the drive(s) and continues operation.  When cache coherency is enabled, 
if either controller encounters a loss of communication with a drive, the firmware will fail the drive.  This 
allows a controller unit to maintain operation during disk-side events.  Once the loss of communication 
is resolved, however, the controller must rebuild all the affected drives.  For large installations, a loss of