K 10 svn:author V 4 ngie K 8 svn:date V 27 2017-10-07T22:59:09.670112Z K 7 svn:log V 1348 MFC r306743,r317712: r306743 (by markj): gmirror: Bump the syncid if broken disks are found during startup. Consider a mirror with two components, m1 and m2. Suppose a hardware error results in the removal of m2, with m1's genid bumped. Suppose further that a replacement mirror component m3 is created and synchronized, after which the system is shut down uncleanly. During a subsequent bootup, if gmirror tastes m1 and m2 first, m2 will be removed from the mirror because it is broken, but the mirror will be started without bumping the syncid on m1 because all elements of the mirror are accounted for. Then m3 will be added to the already-running mirror with the same syncid as m1, so the components will not be synchronized despite the unclean shutdown. Handle this scenario by bumping the syncid of healthy components if any broken mirrors are discovered during mirror startup. r317712 (by markj): Synchronize unclean mirrors before adding them to a running gmirror. During gmirror startup, if component mirrors are found to be dirty as is typical after a system crash, the mirrors are synchronized to the mirror with highest priority. However if a gmirror starts without all of its mirrors present, for example because of some transient delays during tasting, the remaining mirrors must be synchronized before they may become active. END