On Thu, Apr 2, 2015 at 4:25 AM, Alexander Rehbein <alexander.rehb...@fmex.de> wrote: >> > > I've looked in the archive. Sometimes the incr backup is only 20mb, > sometimes 200mb. Perhaps it is an better idea to only backup /var/vmail > directory hourly instead of the full root path.
First, make sure you understand how backuppc works - and the type of your mail files. If you use the old mbox mail format where messages are appended to a single growing mailbox file, and use rsync, only the difference will be transfered, but there is some CPU work involved to compute the changes, and on the server side a complete new file copy will be constructed and stored separately. Xfer methods other than rsync will send the whole changed file. If your mail storage uses one message per file like maildir format, rsync will only send the new files (whether doing a full or incremental) and the ones where the content matches the previous copy will all be pooled without taking additional space. Non-rsync xfers will send only new files on incrementals and everything on fulls, but existing content is still found and pooled in storage. Note that 'new' means newer than the previous full unless you have configured incremental levels. So, there won't be much difference in the storage used regardless of your mix of incremental/full runs. The main difference will be in the time they take to complete and possibly the performance impact on the target system. An incremental rsync run quickly skips fields where the length/timestamp match the previous copy where the fulls do a full read of the target content to do a block-checksum comparison, Also, the fulls will rebuild the archive directory tree which may be time-consuming with many small files, but that becomes the new base for incrementals, making the next ones more efficient. -- Les Mikesell lesmikes...@gmail.com ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/