On 12/1/2011 3:21 PM, Long V wrote: > Hi, > > I have set BackupPC to backup a directory where the content is always > wiped and re-populated with 99% of the time same filename and same > content inside the files. File timestamps would be different as they > have been re-generated. > > I expected that BackupPC would detect it's the same filename and same > content and use hardlink instead of re-copying the file again. > > However, I've been monitoring /var/lib/BackupPC/cpool using `du -sh > /var/lib/BackupPC/cpool` and it seems to be growing at a steady state > that is much faster than what I expected. > > Either I am not looking at the right pool or the way I measure the pool > size (du -sh) is wrong or BackupPC is not using hardlink in my case. > > To confirm my suspicions: > - is /var/lib/BackupPC/cpool the pool I need to look for > - is `du -sh` the proper way to measure the size of the pool > - how do I know how many hardlinks are pointing to the same file in the > pool? > - how do I calculate the saving ratio of using hardlink vs simple copy > the file again? (this would confirm if my instance of BackupPC is > exploiting the saving advantage of hardlink or not)
The simplest way to determine if hardlinks are being used is to cd into a backup directory under /var/lib/BackupPC/pc and run 'ls -l'. The number between the permissions string and the owner's name is the number of hardlinks to the file. In most normal directories this number will be 1 for almost all of the files. In a BackupPC backup directory, the number will be at least 2 (pool and current directory) -- more if the file is being hardlinked to other backups. -- Bowie ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ BackupPC-users mailing list [email protected] List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
