Right now we do a lot of hard to hard disk backup by using rsync to weekly "mirror" the source filesystem to a backup filesystem. This works fairly well for most sources. However, one issue with rsync is that simple things like changing the file name or directory name cause the whole file or directory structure to get recopied over a previous sync. Also, like for mail spools, large files that simply get appended to get the whole file recopied. Does anyone know of something that syncs an ext2/3 fs to another at the block level which result in less data transfer? -- --------------------------------------------------------------- Paul Raines email: raines@nmr.mgh.harvard.edu MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging 149 (2301) 13th Street Charlestown, MA 02129 USA
From: "Paul Raines":> cause the whole file or directory structure to get recopied over aprevious sync There is several rsync switch the with tell the receiving side to chunk the directories/files that no longer exist on the sending side: Check out tricks like: --delete --exclude '*logs/' --delete-excluded The rsync man page is very good.> mail spools, large files that simply get appended to get the whole file > recopied.Are you sure? Only to changed bit and checksums should have moved over the wire. Do a rsync on that individual file and echo off the stats. -eric wood
Paul Raines <raines@nmr.mgh.harvard.edu> wrote: Hello.> Right now we do a lot of hard to hard disk backup by using rsync to weekly > "mirror" the source filesystem to a backup filesystem. This works fairly > well for most sources. However, one issue with rsync is that simple things > like changing the file name or directory name cause the whole file or > directory structure to get recopied over a previous sync. Also, like for > mail spools, large files that simply get appended to get the whole file > recopied. > > Does anyone know of something that syncs an ext2/3 fs to another > at the block level which result in less data transfer?No. If you are able to use UML, you could copy the whole block device once (creating an image on the backup side), than start the system in an UML session on the source side, using a cow (copy on write) file, and copy that cow file on a daily (weekly/monthly) base. After each backup merge that cow file on the source and on the backup side to the full image (and start a new cow file on the source side). Theoretically the same concept could be achived w/o using UML, but that would need some kernel hacking ;-) But I don't know of any user-space solution for that. Regards, Bodo -- No, there is no program running called explorer.exe.
Hi, here's an article about asynchronous block level replication: http://www.linuxjournal.com/article.php?sid=7265 HTH On Thu, Feb 12, 2004 at 12:51:36PM -0500, Paul Raines wrote:> > Right now we do a lot of hard to hard disk backup by using rsync to weekly > "mirror" the source filesystem to a backup filesystem. This works fairly > well for most sources. However, one issue with rsync is that simple things > like changing the file name or directory name cause the whole file or > directory structure to get recopied over a previous sync. Also, like for > mail spools, large files that simply get appended to get the whole file > recopied. > > Does anyone know of something that syncs an ext2/3 fs to another > at the block level which result in less data transfer? > > -- > --------------------------------------------------------------- > Paul Raines email: raines at nmr.mgh.harvard.edu > MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging > 149 (2301) 13th Street Charlestown, MA 02129 USA > > > > > _______________________________________________ > Ext3-users mailing list > Ext3-users at redhat.com > https://www.redhat.com/mailman/listinfo/ext3-users-- Regards, Isaac () ascii ribbon campaign - against html e-mail /\ - against microsoft attachments