On 06/01/2017 12:12, Andriy Gapon wrote: > To add more substance, here is what gets logged when the disk disappears: > > GEOM_MIRROR: Request failed (error=6). ada0p2[READ(offset=2517700608, > length=4096)] > GEOM_MIRROR: Device swap: provider ada0p2 disconnected. > > And here's what gets logged when the disk reappears: > GEOM_MIRROR: Component ada0p2 (device swap) broken, skipping. > GEOM_MIRROR: Cannot add disk ada0p2 to swap (error=22).
I think I see a problem. There are three places where G_MIRROR_DISK_STATE_DISCONNECTED event is posted: 1. g_mirror_orphan() that is called when GEOM notifies us that a disk is gone 2. g_mirror_regular_request(), when we get an error writing or reading data 3. g_mirror_sync_request(), when e get an error writing data to a disk being synchronized 4. g_mirror_write_metadata() when we get an error while writing (updating) the metadata to a member's label #1 is called when the disk disappears when there is no I/O. If the disk disappears while there is some I/O, then we can get either #1 or #2. We can get #3 during disk re-synchronization. We can get #4 in "rare" cases when we update the metadata (e.g. change the mirror configuration). In case #1 the code sets G_MIRROR_BUMP_SYNCID flag before posting the event. In cases #2, #3 and #4 the code sets G_MIRROR_BUMP_GENID flag. I believe that the code should set G_MIRROR_BUMP_GENID only in case #4. In that case the metadata becomes different between the mirror members and, thus, there is no way for the code to automatically rebuild the mirror. In cases #1, #2 and #3 only the data becomes stale on a member and, thus, there should be a chance to re-synchronize that member. In fact, in case #3 the member is already being synchronized. I could be missing something, of course. So, any comments and corrections are very welcome. Thanks! -- Andriy Gapon _______________________________________________ freebsd-geom@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-geom To unsubscribe, send any mail to "freebsd-geom-unsubscr...@freebsd.org"
