Comment 5 for bug 1287318

I don't see how your response shows it's working. The problem isn't that pt-diskstats isn't producing something, it's that the something doesn't contain the data from the files after the first file listed on the command line.

Here's another demonstration of the bug using the number of lines that pt-diskstats is producing:

cap@vega:/tmp/foo$ ~/tmp/percona-toolkit-2.2.7/bin/pt-diskstats --version
pt-diskstats 2.2.7
cap@vega:/tmp/foo$ ~/tmp/percona-toolkit-2.2.7/bin/pt-diskstats 5-sec-status-2014-02-27_09-diskstats | wc -l
1215
cap@vega:/tmp/foo$ ~/tmp/percona-toolkit-2.2.7/bin/pt-diskstats 5-sec-status-2014-02-27_10-diskstats | wc -l
1860
cap@vega:/tmp/foo$ ~/tmp/percona-toolkit-2.2.7/bin/pt-diskstats 5-sec-status-2014-02-27_09-diskstats 5-sec-status-2014-02-27_10-diskstats | wc -l
1215
cap@vega:/tmp/foo$ ~/tmp/percona-toolkit-2.2.7/bin/pt-diskstats 5-sec-status-2014-02-27_10-diskstats 5-sec-status-2014-02-27_09-diskstats | wc -l
1860

The output from the last two commands is the same as the output from the first two commands, meaning multiple files from the command line are not all being processed.