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Re: rsync under cygwin too slow


Alfred von Campe wrote:
rsync -rtuplg --stats --verbose --progress --modify-window=2 /cygdrive/c/localfolder /cygdrive/z/backups/
...
...
The local and remote folders were already synchronized, that is why 0 files were transferred. File list generation did take only 3 minutes but the whole process took more than 1.5 hours to finish and consumed a whopping 1.9 GB of downloaded bytes and 0.4 GB of uploaded bytes as per network counters. For what? Zero files, Zero bytes of file data.

I'm pretty sure this is because rsync has to copy all the files locally to compare them to see if they need to be copied. Try running the rsync as a service on the system that hosts the Z: drive (or run rsync over ssh to the system that hosts the Z drive) and you will see large performance improvement.

Looks to me there is no --checksum option, so rsync skips based on size and modtime. I do something similar to Vinod. Here is an extra data point to compare against (y and u are on separate drives on same machine):


$ time rsync -a --progress --stats --delete /cygdrive/y/Installs/ /cygdrive/u/Installs/
sending incremental file list


Number of files: 284
Number of files transferred: 0
Total file size: 2284961277 bytes
Total transferred file size: 0 bytes
Literal data: 0 bytes
Matched data: 0 bytes
File list size: 8583
File list generation time: 0.030 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 8606
Total bytes received: 22

sent 8606 bytes  received 22 bytes  17256.00 bytes/sec
total size is 2284961277  speedup is 264830.93

real    0m0.678s
user    0m0.155s
sys     0m0.217s

With --checksum:

$ time rsync -ac --progress --stats --delete /cygdrive/y/Installs/ /cygdrive/u/Installs/
sending incremental file list


Number of files: 284
Number of files transferred: 0
Total file size: 2284961277 bytes
Total transferred file size: 0 bytes
Literal data: 0 bytes
Matched data: 0 bytes
File list size: 12951
File list generation time: 5.476 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 12974
Total bytes received: 22

sent 12974 bytes  received 22 bytes  234.16 bytes/sec
total size is 2284961277  speedup is 175820.35

real    0m55.964s
user    0m23.388s
sys     0m7.202s

[snip snip]

-- Cheers, Kein-Hong Man (esq.) Kuala Lumpur, Malaysia

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