When doing a 'svnadmin hotcopy', file/directory modification times are not preserved from the original files in the repo. This causes an efficiency issue when backups are done using rsync. For example backups in our environment are done in the following way: On the subversion server svnadmin hotcopy is done to make a stable copy of the repository. From the backup server, a zfs snapshot is taken (to keep the old data around) and rsync is initiated to pull the updated hotcopy to the backup server. Later the files are backed up to tape using networker. The problem is that every time a new hotcopy is done, the times stamps are updated which forces rsync to re-copy the entire repository hotcopy. This also makes the zfs snapshot take up a _lot_ more space and forces networker to back up the (mostly unchanged) contents again. I am able to use the rsync options --omit-dir-times and --checksum to make the disk space issue go away, however doing a checksum on each file is much more time and resource consuming, especially on huge repositories. Ideally svnadmin hotcopy would preserve the modification times on files and directories from the original repo when creating the hot copy. This would eliminate the issue and make rsync backups _much_ more efficient.
Original issue reported by bugmenotimjustreportingabug