On Mon, Apr 28, 2008 at 08:59:46AM +0300, Shachar Shemesh wrote: > Robin Lee Powell wrote: > > > > How about 73? Surely not a block aligment. :D > > > > dd if=/dev/urandom of=test_rand_wierd bs=1 count=73 > > cat test_rand_wierd test_long1 >test_wierd1 > > cat test_rand_wierd test_long1 >test_wierd2 > > cat test_rand_wierd test_long1 test_rand_wierd >test_wierd3 > > > All files begin and end the same way, so I'm not sure what you are > trying to test here.
That's because I mis-typed; the first one was: cat test_long1 test_rand_wierd >test_wierd1 > Try this: > > dd if=/dev/urandom of=random1 bs=1024 count=16 > dd if=/dev/urandom of=random2 bs=1024 count=1024 > dd if=/dev/urandom of=pad bs=1 count=73 > > cat random1 random2 > before > cat random1 pad random2 > after > > Now see if rsync manages to save much when it has "before" and it > needs "after" (or vice versa) Made two copies, so I could do both: sent 1049756 bytes received 6229 bytes 2111970.00 bytes/sec total size is 1064960 speedup is 1.01 sent 1048929 bytes received 6271 bytes 2110400.00 bytes/sec total size is 1065033 speedup is 1.01 So, no. With larger files, it's better, but still not great: dd if=/dev/urandom of=random1 bs=1M count=16 dd if=/dev/urandom of=random2 bs=1M count=17 dd if=/dev/urandom of=pad bs=1 count=73 cat random1 random2 > before cat random1 pad random2 > after cat random1 random2 > before2 cat random1 pad random2 > after2 sent 17841045 bytes received 41226 bytes 5109220.29 bytes/sectotal size is 34603008 speedup is 1.94 sent 17841118 bytes received 41226 bytes 3973854.22 bytes/sec total size is 34603081 speedup is 1.94 So about half the file is sent; presumably the random1 part. And rsyncrypto does, in fact, do far better, fwiw. cat random1 random2 > before cat random1 pad random2 > after cat random1 random2 > before2 cat random1 pad random2 > after2 rsyncrypto plain/before cipher/before keys/before backup.key rsyncrypto plain/before2 cipher/before2 keys/before backup.key rsyncrypto plain/after cipher/after keys/before backup.key rsyncrypto plain/after2 cipher/after2 keys/before backup.key sent 81235 bytes received 41296 bytes 35008.86 bytes/sec total size is 34661412 speedup is 282.88 sent 81299 bytes received 41296 bytes 49038.00 bytes/sec total size is 34661476 speedup is 282.73 -Robin ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Rsyncrypto-devel mailing list Rsyncrypto-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rsyncrypto-devel
