Why does't rsync use delta-transfer for local files ?
- by o_O Tync
I have a big iso image which is currently being downloaded by a torrent client with space-reservation turned on: that means, file size is not changing while some chunks in in (4 Mib) are constantly changing because of a download.
At 90% download I do the initial rsync to save time later:
$ rsync -Ph DVD.iso /some/target/
sending incremental file list
DVD.iso
2.60G 100% 40.23MB/s 0:01:01 (xfer#1, to-check=0/1)
sent 2.60G bytes received 73 bytes 34.59M bytes/sec
total size is 2.60G speedup is 1.00
Then, when the file's fully downloaded, I rsync again:
total size is 2.60G speedup is 1.00
Speedup=1 says delta-transfer was not used, although 90% of the file has not changed. Why?!
