Slow transfer speed over network on Mac

[kilrah]

I'm using FFS to sync a folder between 2 macs through a gigabit Ethernet network, but somehow only getting transfer speeds up to about 25MB/s, that often can fall down to 10MB/s or less for several seconds. Copying the same files that would be synced manually from the Finder results in full ~100MB/s speeds, finishing the transfer of 10GB of files in <2 minutes instead of 8-10.

Any idea what could cause that? I could reproduce with all of 8.0, 8.1 and 8.2.

[Seven_709]

This might still be an issue. Currently running FFS 9.3 and sync between two MACs. Transfer speed is ~35 MB/s with average file size of 2 GB. However, when I start copying files within finder at the same time (and about the same size), I easily hit 110 MB/s which would the maximum of my 1Gbit LAN connection.

Any hint to solve this issue would be most welcome.

[jimalcock]

I am too experiencing sloooow transfer. Running FFS 9.3 on a Mac Server (10.9.5) with an external Promise Pegasus2 R6 RAID attempting to mirror to a Buffalo Terastation 51210R. Ran the compare, took a while but it was about 4TB so expected. Starting syncing, ok speed, expected it to take about 24 hours but 3 days later speed had reduced to a crawl (<20KB/sec). Stopped it, reran the compare, about 800GB remaining, set it off again, good speed, ten minutes later back to <20KB/sec. 24 hours later, currently running at 15KB/sec with 390 days remaining to copy 780GB!!!

Neither the Mac or the Terastation are under any sort of load, CPU, IO etc all low. Any ideas?

[Zenju]

I've made a few tests and it seems there is indeed a speed difference between FFS and say Finder, which is suprising considering that FFS has a similar implementation like "cp". Unless... Finder does some proprietary internal tricks that cp does not...

Do you find a speed difference between cp and Finder?

[jimalcock]

Ok, so i opened two finder windows, one from the source - the RAID and the other for the destination - new NAS server and dragged a 9GB folder across. This took about two minutes.
I then opened a terminal session and "cp'd" a similar 9GB folder from the same source to the same destination folders. This again took about 4 minutes (same folder size but considerably more items).
Both of these are acceptable to me. I have had FFS running this morning for just under 3 hours and it has copied very little at around 150KB/sec - reporting 30 days to copy the remaining 765GB.

[jimalcock]

Ok, so maybe a bit longer than 30 days now... :-(

transfer5.jpg (29.58 KiB) Viewed 2288 times

[jimalcock]

Just to show...current state of copying with FFS

copy2.jpg (10.38 KiB) Viewed 2272 times

Copying some of the files via Finder

copy1.jpg (9.2 KiB) Viewed 2272 times

[Zenju]

Seems the issue has been fixed:
viewtopic.php?t=4808