Problem with checksum failing on large files
craig at atheros.com
Mon Oct 14 16:48:01 EST 2002
> I tried "--block-size=4096" & "-c --block-size=4096" on 2 files (2.35 GB &
> 2.71 GB) & still had the same problem - rsync still needed to do a second
> pass to successfully complete. These tests were between Solaris client & AIX
> server (both running rsync 2.5.5).
Yes, for 2.35GB there is a 92% chance, on average, that it will fail
with 4096 byte blocks.
> As I mentioned in a previous note, a 900 MB file worked fine with just "-c"
> (but required "-c" to work on the first pass).
> I'm willing to try the "fixed md4sum implementation", what do I need for
The "fixed md4sum" refers to some minor tweaks for block lengths of
64*n, plus files bigger than 512MB, to get correct md4 sums. But this
shouldn't make a difference for you.
Would you mind trying the following? Build a new rsync (on both
sides, of course) with the initial csum_length set to, say 4,
instead of 2? You will need to change it in two places in
checksum.c; an untested patch is below. Note that this test
version is not compatible with standard rsync, so be sure to
remove the executables once you try them.
--- checksum.c 1999-10-25 15:04:09.000000000 -0700
+++ checksum.c.new 2002-10-14 09:40:34.000000000 -0700
@@ -19,7 +19,7 @@
-int csum_length=2; /* initial value */
+int csum_length=4; /* initial value */
#define CSUM_CHUNK 64
@@ -120,7 +120,7 @@
if (remote_version >= 14)
- csum_length = 2; /* adaptive */
+ csum_length = 4; /* adaptive */
csum_length = SUM_LENGTH;
More information about the rsync