K 10
svn:author
V 5
markj
K 8
svn:date
V 27
2017-11-30T20:36:29.795758Z
K 7
svn:log
V 637
Update gmirror metadata less frequently when synchronizing.

We periodically record synchronization progress in the metadata
block of the disk being synchronized; this allows an interrupted
synchronization to be resumed. However, the frequency of these
updates heavily pessimized synchronization time on some media. This
change modifies gmirror to update metadata based on a time period,
and adds a sysctl to control that period. The default value results
in a much lower update frequency and increases the completion time
for an interrupted rebuild only marginally.

Reported by:	Andre Albsmeier <andre@fbsd.e4m.org>
MFC after:	3 weeks

END