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Description of problem:
When VDO's log level is in debug this verifyDuplicationWork can be displayed often in certain configurations.  The meaning of the message is not informative.

Log message:
kernel: kvdo8:cpuQ1: verifyDuplicationWork: match - we win!

How reproducible:
100%


Steps to Reproduce:
1. create vdo volume - vdo create --name=vdo1 --/dev/sdb
2. create vdo volume - vdo create --name=vdo2 --/dev/mapper/vdo2
3. echo debug > /sys/kvdo/log_level
4. write data to vdo2
5. monitor logs

Actual results:
Log message:
kernel: kvdo8:cpuQ1: verifyDuplicationWork: match - we win!

Expected results:
Log message:
kernel: kvdo8:cpuQ1: verifyDuplicationWork: match 
or 
a message that is more descriptive 

Additional info:

I was able to reproduce it easily with kmod-kvdo-6.1.0.72-10 on kernel 3.10.0-799. So I updated kernel to 3.10.0-820 and updated kmod-kvdo to 6.1.0.98-11. I repeated the same steps but was not able to get a single message in logs on debug log level.
Ken, is this fixed by removing the log entry altogether? And if it is the case,  how to verify deduplication of certain data now?

Yes, the messages have been removed.

You can still check the dedupe stat counters before and after a set of I/O requests.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2018:0900