On 4/29/2010 9:09 PM, Busby wrote: > Hi, Phillip Susi, > Why not suspend the origin's IO first, then create the > snapshot lv, resume the origin lv 's IO waiting Q last. the 'dd' cmd is > eariler than the snapshot's creating, if suspend the IO, the filesystem > on the snapshot will be corrupt, I get it, but I think the snapshot is > in block layer, should suspend the user layer's data coming first, then > flush the data in the dirty buffer and create the snapshot. like the dd > cmd on the origin, will make the snapshot's creating take a very long > time, for waiting for the dm suspend 's return, I think flush the data > in the dirty buffer (data from dd ), suspend the next data of the dd, > create the snapshot, then let the data into dirty buffer to the block > layer. the dd cmd will put the data into dirty buffer continually, can > not be suspended? I don't think it is possible to suspend new IO requests from user land while allowing it from the buffer cache. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
