Freek de Kruijf wrote:
Op woensdag 23 juli 2014 14:16:40 schreef auxsvr@gmail.com:
On Wednesday 23 of July 2014 10:22:06 Daniel Bauer wrote:
Hi,
Hi,
When I copy a file on my server, using drag and drop with two dolphin windows I get a transfer speed of approx. 35-40 kB/s.
When I use rsync to copy the same files I get a speed of approx. 85-90 kB/s.
Where does this difference come from?
Maybe rsync uses compression of the data?
On a local copy or local network, that usually slows down transfers. On might ask why rsync is so slow -- copying 800G from 1 partition to another via xfsdump/restore takes a bit under 2 hours, or about 170MB/s, but with rsync, on the same partition with rsync transfering less than 1/1000th as much (700MB), it took ~70-80 minutes... or about 163kB/s. That's on the same system (local drive -> another local drive) Transfer speeds depend on many factors. One of the largest is transfer size (how much transfered with 1 write /read. Transfer 1GB, 1-meg at a time, took 2.08s read, and 1.56s to write (using direct io). Transfer it at 4K: 37.28s, to read, and 43.02s to write. So 20-40x can be accounted for just on R/W size (1k buffers were 4x slower). Many desktop apps still think 4k is a good "read size" Over a network, causes drop from 500MB/s down to less than 200KB/s (as seen in FF and TB). Optimal i/o size on my sys is between 16M-256M. So -- to answer your question, MANY things can affect speed, but I'd look at the R/W size first. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org