Page tree
Skip to end of metadata
Go to start of metadata

Article State

Approved

Article Number

KB-20170623162300

Product

Disk Library for mainframe DLm2100,Disk Library for mainframe DLm8100
SummaryDLM0047E DLm0503E DLm0515W causes major issues on Release 4.5.0P1, Skew of movement of tapes with efsmove caused unbalanced filesystem usage leading to performance issues and replication issues . Upgrade to 4.5.0P2 is highly recommended.

Language

EN

DE

Issue

DLm  Release 4.5.0P1 has presented with several symptom patterns and errors including:  DLm0047E.


In the btilog messages similar to :

"vte1 VT: DLm0047E: Internal Error searchTapelibList: Failed to obtain lock while searching tapelib 
'/tapelibDLMV/CEL1_P1_FS1': Connection timed out ".


The bug that caused the  DLm0047E results in creating  redundant tapelibrary management tasks

   The multiple tasks keep struggling which results in higher CPU load and in a lot of other error messages occurring due to abnormal situation.

   Basically , the way the system handles the  DLm0047E is wrong and  works inappropriately.


Also seen on Release 4.5.0P1 - continuous messages:

 DLm0503E: Error erasing volume xxxxxx Not found (E7)” and

“DLm0515W: Volume ~XXXXXX file is open elsewhere, cannot erase” messages from occurring.  These continuous messages will fill the btilog file.


“query locks” may report the same lock multiple times

 “find” may show the same tape multiple times


Another major side effect of the bug  seen on release 4.5.0P1 is the skew of the tape movement  using EFSMOVE to a few directories and ignoring most

other directories. This can cause the overused or out of balanace directory to reach the critical space limit or to be continually running space recovery by

erasing of tapes and the unbalance of the directories will affect performance of the DLm including replication performance.



Cause

DLm Release 4.5.0P1 has a bug  that caused  the DLm0047E and also caused the  DLm0503E and the DLm0515W continuous  messages.

Solution

The resolution to the issue of the DLm0047E ,DLm0503E,  DLm0515W is to upgrade to DLm Release 4.5.0P2 - this level has the fix for the issues.  

Customers could encounter serious performance degradation with DLm 4.5.0P1 installed.  It is essential to monitor the space usage 

Troubleshooting DLm Space Usage regularly while this condition exists.

As a workaround, periodically rebooting the VTEs affected may provide some short, temporary relief to the accumulated threads and resulting error

messages, but it is only temporary.  


Workaround

Notes

from the release notes on 4.5.0P2 :
"ARS 891879: Fixed error "DLm0047E: Internal Error searchTapelibList: Failed to
obtain lock while searching tapelib <directory>: Connection timed out" and errors
associated with it which could occur during space recovery:

ARS 894142: Resolved continuous “DLm0503E: Error erasing volume xxxxxx Not found (E7)” and “DLm0515W: Volume ~XXXXXX file is open elsewhere,

cannot erase” messages from occurring




Attachments


Change

Upgrade to DLm 4.5.0P1