On 01/11/2013 07:08 PM Reindl Harald wrote:
.... different versions of the backup daily, weekly, monthly
Ah, yes, in that kind of scenario hard links would be useful.
unchanged files are replaced with hard-links the destination files are virtually on the same place
And so then could changes to a file be recorded in the daily version as a diff against the weekly?
On Sat, Jan 12, 2013 at 3:46 AM, ken gebser@mousecar.com wrote:
On 01/11/2013 07:08 PM Reindl Harald wrote:
.... different versions of the backup daily, weekly, monthly
Ah, yes, in that kind of scenario hard links would be useful.
Backuppc does it by matching the content, so it can pool the duplicate data even if the copies are found in different places or on different backup targets.
unchanged files are replaced with hard-links the destination files are virtually on the same place
And so then could changes to a file be recorded in the daily version as a diff against the weekly?
I think rdiff-backup can save deltas. Rsync itself and backuppc will send deltas over the network but end up reconstructing a complete copy of the target file even for small differences. At least backuppc can compress the resulting file for storage.
On 2013-01-12, ken gebser@mousecar.com wrote:
On 01/11/2013 07:08 PM Reindl Harald wrote:
.... different versions of the backup daily, weekly, monthly
Ah, yes, in that kind of scenario hard links would be useful.
unchanged files are replaced with hard-links the destination files are virtually on the same place
And so then could changes to a file be recorded in the daily version as a diff against the weekly?
Not with rsync or rsnapshot. If you make a change in one line to a 48GB file, rsnapshot will remove the appropriate hard link (leaving the others alone) and create a new 48GB file at a new inode. (Because rsnapshot uses rsync, the data transfer for this change is still fast, but it's still 2x storage.)
--keith
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Keith Keller -
ken -
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