On Mon, Nov 16, 2009 at 11:50:56AM -0500, Mikulas Patocka wrote: > When there are no writes pending for a given region, we set the bit in > memory, indicating that the region is clean. > Some times later (usually while setting another dirty bit in the log), we > write the log to disk. > Before writing the log, we must flush cache on both mirror legs. > (otherwise, we might write some bit as clean while the data is still > pending in the disk cache) > > If this flush fails, the bits in memory are already clean and we don't > know which regions may hold unwritten data in the disk cache and which Actually we do: the on-disk version of the log tells us. > not. So, we must set all regions as dirty. Anyway, let's not try to handle these situations at the moment. what I need for now, is a way to know whether or not this situation has actually occurred when we get reports from users, so probably a kernel log message, a dm event raised plus a failure indicator against the device in the status line. Alasdair -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
