T10000B - FSC 407B Errors And Possible Slow Performance

Asset ID:	1-72-2079065.1
Update Date:	2017-08-09
Keywords:

Solution Type Problem Resolution Sure

Solution 2079065.1 : T10000B - FSC 407B Errors And Possible Slow Performance

Applies to:

Sun StorageTek T10000 Tape Drive - Version All Versions to All Versions [Release All Releases]
Sun StorageTek T10000B Tape Drive - Version All Versions to All Versions [Release All Releases]
Information in this document applies to any platform.

Symptoms

Customer is experiencing performance problems and tapes with 407B errors. 1 account said that this problem got much worse when 1.52.203 code was installed. See bug 22167813. This problem only affects T10000B as it is ALP related.

Cause

407B errors occur due to the drive having CRC errors trying to read the MIR. This will cause the drive to post the Invalid MIR tape alert flag but not on every mount that takes a 407B error. If the account is running on down-rev VSM code then VTCS will unload the drive and preference the mount to the backup copy which can put an extra load on the backup site resources and takes extra time.

Code 1.52.203 may make this problem worse. This code versions will set the Invalid MIR tape alert which will go back to VSM. Code version 1.48.212 did not set the Invalid MIR tape alert for Invalid MIR conditions.

Solution

If an account is experiencing performance problems that seem to be positioning related with FSC 407B errors in the event log then do the following:

1. Verify the tape drive code level. If it is 1.52.203 then consider going back to 1.50.203 code until 1.52.206 code releases.

The next code release for T10000B (currently targeted at 1.52.206) will go back to not setting the Invalid MIR tape alert for Invalid MIR conditions. In addition a code change has been created that will address the root cause of the 407B error which should also come out in the next code release.

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