On Sun, Jun 28, 2009 at 6:13 PM, Fernan Bolando<fernanbola...@mailc.net> wrote: > man vac > "-q Increase the performance of the -a or -d options by detecting > unchanged files based on a > match of the files name and other meta data, rather than > examining the contents of the files" > > Why is -q not a default? Is there a reliability concern with that option?
If the file contents change but the mtime and size remain the same, then vac -q will not notice the change and will not back up the new file contents. Some people worry about this case, others don't. Hence the flag. > I am currently doing an hourly backup using > > vac -d old_date-time.vac -f new_date-time.vac /home > which gives me a collection files with a date-time.vac filename. > > I am thinking I should just use vac -a main.vac /home > to switch to this method I only need to rename latest date-time.vac to > main.vac > and delete the other ones, right? vac -a creates a tree inside the vac archive. It expects the archive to have a top-level directory 2009 and subdirectories 0627, 0628, etc. You would need to change your vac tree to have that top-level structure before it would be valid input to vac -a. If you run it multiple times per day, the subdirectories for today would be named 0629, 0629.1, 0629.2, 0629.3, and so on. You can do this by building a local file tree with the right structure and using vac -m. On Sun, Jun 28, 2009 at 10:02 PM, Nathaniel W Filardo<n...@cs.jhu.edu> wrote: > It uses an astronomically large amount of memory, if nothing else. > Mirroring a little over 100MB of data from sources with vac -q occupies > roughly 85MB in core. Whether you use -q should have no effect on the memory usage. There may be a memory leak somewhere involving -q, but at first glance I don't see one. Feel free to investigate. Russ
