B2D Slows Only When Doing 'C' Drives

[David_Penrice]

Has anyone else encountered this issue:-

When backing up any 'C' drive, locally or remotely to a B2D (attached NAS via SAS 4GB connection), I only get about 400-500mb/min backup speed but as soon as it gets to the other drives 'D', 'E' etc on the same server (same disk parition) i get a speeds up to 3200mb/min?

I have also made sure that system state, shadow etc are all turned off while i do these tests.

Now if i backup that same drive directly to an LTO3 drive, i get 948mb/min or more.

I've tried this with a number of remote (inhouse based with a 2GB backbone) with the same results, c drive slow, d drive super fast.

I'm running 11d with all the patches, on a Dell 1950 with windows 2003 standard R2 SP2 and the nas is two Dell MD1000 daisy chained if that helps. (the servers as also 2003).

Thanks in advance

[Ben_L_]

David,

Have you tried to run a defrag on the servers C drive?  I know it may sound odd that all of them are having the same issue, but I have run across an issue like you have described before and once the defrag was run the speed increased back to normal.

[David_Penrice]

Thank you for the reply Ben.

I'd already thought of that one too :) in my case it didn't seem to make much difference - it just seems strange because it seems to be only on C drives, and again if it was something to do with shadow copies etc but i don't have any of that turned on...

:(

[Ken_Putnam]

Don't know if this will help, but it has solved  a couple of strange network throughput problems recently.  (Including one that would backup fine to Disk, but was slow to Tape on the same system!)

From a cmd prompt execute

"Netsh int ip set chimney DISABLED"

[David_Penrice]

Thank you for the reply.

I tried it and it made no difference to the speed.

I've had a ticket open with support for over a week with out any luck....

Thank you again for the idea.

Regards,

Dave