2013-04-22 15:44, sf...@users.sourceforge.net skrev: > Hello Christian, > > Christian Huldt: >> Since there is a considerable difference in size, I would like to "copy >> down" changes from >> /mnt/newssd to /mnt/olddisk about once a week. > If you mean real "copy-down" instead of "move-down", then it is mostly > harmless because aufs handles the top-most file. Even if the same named > file is created on the lower branch, it doesn't matter. > But the upper writable branch usualy contains a whiteout. After simple > rsync, the lower branch will have both of real entry and a whiteout for > it. eg. "fileA" and ".wh.fileA". As long as your lower branch is at the > bottom of the layer, it will be still harmless (I guess). If you > re-order the layers or use the the lower branch for another aufs's upper > branch, then aufs will be confused and will not work correctly I am > afraid. For such case, you should run auchk for that branch which checks > "Illegal whiteout", "Remained pseudo-links", and "Remained temp files" > and cleans the garbages such like generic fsck. > > Moreover, for the dir, it will make aufs busy a little. Generally > speaking, when you read a dir via ls(1) or something, aufs tries reading > all entires on under the dir on all branches. Here the same named lower > entires will be hidden, but the internal aufs work increases. > > If you mean "move-down", I mean "remove the copied-down files", then > simple rsync will be harmful. It will surely confuse aufs. > > Finally the most recommended way is aubrsync. But it should be used at > the system shutdown time (or when the unmounting aufs time). > I have a plan to support "live move-down" feature, but I don't know when > it will complete. That sounds interesting!
I assume I mean "move-down" and will hence use aubrsync. I intend to run it at "idle time" and suspend services. I take it that I should unmount and re-mount aufs afterwards, or would "mount -o remount" be sufficient? -- mvh Christian Huldt +46704612207 ------------------------------------------------------------------------------ Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis & visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter
