SQL Server Books online defines LOGMGR as “Occurs when a task is waiting for any outstanding log I/Os to finish before shutting down the log while closing the database “

Depending on what other waits are occurring – this could indicate an IO bottleneck. For example , if ASYNCH_IO_COMPLETION,IO_COMPLETION,WRITELOG,PAGEIOLATCH_x  are involved this is a strong indicator of the IO bottleneck.

If you want to doublecheck – collect Current Disk Queue Length  , which will indicate that the IO subsystem is struggling to complete throughput

Any SQL Server task waits for IO completion – this is completely normal part of SQL Server processing. But when the wait for IO completion is slow there is a problem

A few  issues to consider and approached to minimizing LOGMGR

1)Maintain Random access \ Sequential access files  on different drives . Particuarly focus on isolating the transaction log file . Work with you storage administrator – in identifying the optimal configuration to assist in throughput

2)Are you experiencing IO delay messages in the error logs. This is a strong indicator , as it reports on IO delays – outside of the SQL Server process space.

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