Poor network transfer speed

cavemanoc · 23 May 2010 at 20:29

Trying to pull 500Gb off a WD My Book World so I can change it from Raid 0 to Raid 1. Transfering the data to my WHS via Gigabit ethernet. Should be writing to a Samsung 1.5tb on the WHS box so should easily see 70MB/s speeds. Currently getting:

Where do I start working out where the bottleneck is?

bigredshark · 23 May 2010 at 20:58

You're transferring a very large number of files, that'll slow it down straight off, particularly on a single drive as the number of IOs and random access is going to be an issue. Run iperf and make sure you're actually getting gigabit network throughput then work from there...

Yakyb · 24 May 2010 at 11:08

try copying it using a xcopy script and monitor the bandwidth using task manager

would never transfer lots of small files using copy and paste

bigredshark · 24 May 2010 at 12:43

Yakyb said:
try copying it using a xcopy script and monitor the bandwidth using task manager

would never transfer lots of small files using copy and paste

Actually if you're going to do that it'd make far more sense to use robocopy, given the latest versions have a multi threaded option. I'm unconvinced either will make a major difference though, windows file copy routine is fairly well engineered these days...

Yakyb · 24 May 2010 at 14:13

never used robocopy but i have heard good things, but Xcopy does make an enormous difference for lots of files in one transfer.

Yakyb · 24 May 2010 at 14:17

oh in terms of determining an actual issue i would look at Iperf, its a command line app that allows you to test your theoretical bandwidth between two machines as well as monitoring ping rates

iperf helped me find that the supposed GB nic in an older motherboard never actually gave me more than 25mb/s quick purchase off the bay and everything was at 85mb/s

if that is saying you are low, i would start looking at updating drivers or seeing if the same happens when using a linux boot cd

after that i would start looking into replacing cables / nics / switches in that order

wonko · 24 May 2010 at 16:30

You're using your desktop to copy from the WD NAS onto a WHS box?
I'd start by copying a large file or two from the WD NAS to your desktop, and then separately copying those files from your desktop to the WHS box. If you crudely monitor file transfer rate or netowork utilisation (task manager) for each of these steps you'd at least you'll know which is the weakest link to look at first.

I also stumbled across this - my guess is that the WD NAS will be the weak link:
http://en.wikipedia.org/wiki/Western_Digital_My_Book#Network_speed

cavemanoc · 24 May 2010 at 19:08

Thanks for all the answers - I'm working through them ATM to try to nail the culprit. I was copying the files using cut and paste from my laptop looking at the 2 network resources, which (I think) was forcing it to copy from the WD to the Laptop and then on to the WHS box :eek:

I subsequently used remote desktop to cut and paste direct from the WD to the WHS and that has dramatically improved speed but I can't accurately tell as the WHS doesn't report gross transfer speed the way Win 7 does

Gut feel is it's still only transferring at about 5MB/s so a factor of 10 off what I'd expect, but in line with what Wonko found in the WD link :mad:

Once I'm done I'll try a transfer from the WD direct to the laptop of a single large (8Gb+) file and see what it's topping out at.

I will look at Iperf - was a bit daunted last time I tried to use it, but will persevere

Edit: Just checked with Taskmgr on the WHS box and I was right - 6% on the Gigabit connection which amounts to about 6MB/s - boo!