duplicity-team team mailing list archive

[gcc <question185550@xxxxxxxxxxxxxxxxxxxxx>]

Question #185550 on Duplicity changed:
https://answers.launchpad.net/duplicity/+question/185550

gcc proposed the following answer:
Actually I think that you need to increase the max-blocksize, not the
volume size. From the manual:

       --max-blocksize number
              determines the number of the blocks examined for changes during the diff process.  For files < 1MB the blocksize is a constant of 512.  For files
              over 1MB the size is given by:

              file_blocksize = int((file_len / (2000 * 512)) * 512)
              return min(file_blocksize, config.max_blocksize)

              where config.max_blocksize defaults to 2048.  If you specify a larger max_blocksize, your difftar files will be larger, but your sigtar files
              will be smaller.  If you specify a smaller max_blocksize, the reverse occurs.  The --max-blocksize option should be in multiples of 512.

So a larger max-blocksize means that when files do change, the diffs are
larger, because they contain more unchanged data along with the changed
data (due to the larger block size), but the index of all those blocks
and their signatures is smaller, because there are fewer of them.

-- 
You received this question notification because your team Duplicity
Users is an answer contact for Duplicity.