On Mon, Mar 24, 2003 at 12:54:26AM +1100, Donovan Baarda wrote: > On Sun, Mar 23, 2003 at 03:46:34AM -0800, jw schultz wrote: > > On Sun, Mar 23, 2003 at 05:45:47PM +1100, Donovan Baarda wrote: > > > On Sun, 2003-03-23 at 07:40, jw schultz wrote: [...] > The block_size heuristic is pretty arbitary, but the blocksum_size > calculation is not, and calculates the minimum blocksum size to achieve a > particular probability of success for given file and blocksum sizes. You can > replace the block_size heuristic with anything, and the second part will > calculate the required blocksum size. > > > I do have a variant that scales the length devisor for block > > size from 1024 to 16538 as the length progresses from 1MB to > > 128MB. This in conjunction with your sum2 length formula > > produces this: > > That sounds pretty arbitary to me... I'd prefer something like having it > grow at the square-root of filesize... so 1K for 1M, 8K for 64M, 16K for > 256M, 32K for 1G, etc.
A thought occurred to me after writing this; a viable blocksize heuristic is just a fixed block size. This makes the signature size almost proportional to the filesize, except for the growth in blocksum size. I don't necisarily advocate it though. I think increasing the blocksize is a good idea as files grow because file and signature size also contribute to CPU load. -- ---------------------------------------------------------------------- ABO: finger [EMAIL PROTECTED] for more info, including pgp key ---------------------------------------------------------------------- -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.tuxedo.org/~esr/faqs/smart-questions.html