On Wed, 2006-02-01 at 16:51 -0500, Brian J. Murrell wrote: > On Wed, 2006-02-01 at 13:29 -0800, Dan Stromberg wrote: > > It just maintains a series of hardlink trees, so any time a file is > > deleted or added, the actual disk usage increase is only due to the > > changes. > > Yes, this is quite a popular technique. To be clear though, a change in > a file does not consume just the amount of the change in the file on the > backup target, but it consumes the entire size of the new file. A > not-so-insignificant amount for very large files. This is where a > (block level or filesystem level) snapshotting scheme would excel as it > would likely only consume an amount of space rounded up to the next > "unit" size more even for changes within a file. it depends. assume u have a huge text file. u change 1 char, the snapshot is useful. u add one line at the beginning, the snapshot is useless here. the offset shift. some delta tech will be useful here. > > Indeed (and to keep quite on topic), perhaps rather than hardlink trees, > LVM snapshots would be even more space efficient. Maybe that is what > this thread has been about. I just jumped in. Apologies if it was. > > b. > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
