Very poor transfer speed from server to workstations over LAN (yet the workstations transfer to the server quickly!)
Posted on 2007-07-25
I'm really hoping there is a simple solution to this because I sure can't think of anything.
-I have a couple of physical servers: DPE2650 and DPE2950. The 2950 is the one with the issues - it's almost brand new and has been acting as our Exchange 2007 server and nothing more since we rolled it out.
-We have a couple of physical switches (3COM 4200 series)
-We have ~50ish workstations spread between the two switches, all on 100mbps ethernet
-DPE2650 is plugged into a gigabit port on one switch.
-DPE2950 (the problem server) is plugged into a gigabit port on the other switch.
-There is a gigabit up/downlink between the two switches.
Transferring files FROM or TO DPE2950 and DPE2650 is a beautiful thing... super fast. Obviously at gigabit speeds. A 150 megabyte file is done in under 10-15 seconds start to finish.
Transferring files FROM any workstation that I have tested so far TO DPE2950, works great too. Speeds are obviously normal for a 100mbps connection... a 150MB file might take a minute or two.
However, I can turn right around and take that very same file I *JUST* transfered from the workstation to the server, and try to transfer it back, and the connection speed is about the most ridiculous thing ever. 1-1.5 hours. I mean it literally acts about like a 10mbps connection would, if not worse.
I have tested workstations that are located on both of the two switches - the one where the 2650 is (which , again, transfers to and from the 2950 just fine). All of them so far exhibit the same characteristic. Well, actually, I take that back. I haven't seen necessarily that transfering TO the server is reasonably quick on any workstation located on the opposite switch from the 2950, but I have tested 'from' the server as being horribly slow no matter which switch the workstation is on.
So I really am lost here... what in the WORLD could be slowing down information being pushed out of the 2950 to the workstations, but not slow down information coming into the server from any workstation, and not slow down information being pushed in or out to the 2650?
My first instinct is to suspect that there might be something to do with the gigabit connection speed. Maybe the 2950 is getting tripped up when trying to push info out to a PC that can only accept it at 1/10th of the speed that it would like to push out at?
I dunno... just a guess.
Come to think of it, most PCs here have gigabit capable ethernet cards. I'm going to try connecting one to a gigabit port on one of the switches and see if uploading from that workstation to the server suddenly becomes lighting quick...
In the mean time, suggestions would be greatly appreciated!