Hello Ted, As you mentioned, It depends alot on your specific usage and how long you want to store the data.
> Anyway, I am wondering if there is any guidance on how much larger the target file system should be compared with the source file system when using rdiff? Here the rules I have when I have little information about he filesystem usage: 1. For business, I multiply the average data size by how many year they want to keep. So if the business have around 150GiB of data and want to keep them for 5 year: 150 x 5 = 750GiB is a good start. That also account for the business growth and files changes. 2. For desktop users is different, the data change less often. I usually just double the capacity. For a user with 250GiB, I will plan 500GiB. Hope it's helping you to plan the capacity. -- Patrik Dufresne Service Logiciel inc. http://www.patrikdufresne.com <http://patrikdufresne.com/>/ 514-971-6442 130 rue Doris St-Colomban, QC J5K 1T9 On Sun, Sep 1, 2019 at 4:55 PM Mike Fleetwood via rdiff-backup-users < rdiff-backup-users@nongnu.org> wrote: > On Sun, 1 Sep 2019 at 19:39, Theodore Wynnychenko <t...@uchicago.edu> > wrote: > > > Hello > > > > I have been searching for an answer or guidance to this question, but > have > > not been able to find anything, so I will ask here. > > > > I am sorry if it has been asked/answered before. > > > > In any case, I am planning on "updating" my backup hardware, and will > > probably switch from rsync to rdiff (I have used rsync for many years, > and > > have been happy with it, except for that one time years ago when I > deleted > > a > > bunch of files and did not notice until about a day later, and 10 minutes > > after the final backup had been synced - a bit disappointing). > > > > Anyway, I am wondering if there is any guidance on how much larger the > > target file system should be compared with the source file system when > > using > > rdiff? > > > > Clearly, rdiff stores more information, so, in theory, if you have two > file > > systems of exactly the same size, and the source is completely full, then > > rdiff would have nowhere to store any historical changes. > > > > Is there a rule-of-thumb, or some sort of calculation that will give > > guidance on how much extra space there needs to be on the target file > > system > > to reliably not have an instance when the target file system becomes > full, > > while the source still has space on it? > > > > It seems this would be based on the frequency of updates, the size of the > > file system, the number and size of files, the types of changes made to > > those files, how long backups are maintained, and probably other things. > > > > I am not looking for anything exact, more just a way to guesstimate. > But, > > I > > am also not opposed to math either, if there is a calculation that can > help > > determine the target file system's appropriate size. > > > > Thanks > > Ted > > > > Just a user here who backups up their home Linux desktop using > rdiff-backup. > > So it all depends on your rate of change of backed up data and how long > you want to keep previous backups for. > > As an example here are some figures from my daily backup: > > Backup Size Pct > -------------- -------- ---- > Current mirror 42.8 GiB 100% > Day 406 increment 65.4 GiB 150% > Day 804 increment 87.2 GiB 200% > > So for *MY* data and *MY* rate of change, 150% is enough for over a year > of daily backups. Make sure your backup file system has enough inodes > as well as free space. > > Mike > _______________________________________________ > rdiff-backup-users mailing list at rdiff-backup-users@nongnu.org > https://lists.nongnu.org/mailman/listinfo/rdiff-backup-users > Wiki URL: > http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki _______________________________________________ rdiff-backup-users mailing list at rdiff-backup-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/rdiff-backup-users Wiki URL: http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki
