Samba performance with 2 NICs does not scale as expected

David Collier-Brown davecb at
Wed May 19 12:10:35 GMT 1999

Ariel Kornberg wrote:
> 0)      We are using 2 FTP clients and 2 Samba clients.
> 1)      The connections are via a switched network using different sub nets.
> 2)      The network configuration is as followed:
>         Unix machine (server): IP- , Subnet
>                                                     IP -, Subnet
>         NT machine (client): IP-, Subnet
>                                                  IP-, Subnet
>         While coping 2 files from the server to the client via samba, we
> clearly see that each file is transferred through a different NIC. To make
> sure we are not wasting time on disk seeks, each file is on a different
> physical hard disk, which means we have two hard disks on the client machine
> and two on the server machine.

	Hmmn: physically, the bottlenecks in the system should be
	disk and network throughput (in that order), and both
	are fine in your scenario. Cpu, bus and the like are
	not going to be a problem in single-file transfers, unless
	its an 8088 (;-))

	The only things left are interference effects in the machines,
	by Sherlock Holmes' dictum (once you remove the impossible,
	whatever's left is the problem).  At least, that's all **I**
	can think of!

	I'd suggest trying a trivial test to see if it's client-side: 
	do a test with two clients. 

	As it stands, it's contra-intuitive... two NICS should not,
	by themselves, constitute a source of bottlenecking.

David Collier-Brown,  | Always do right. This will gratify some people
185 Ellerslie Ave.,   | and astonish the rest.        -- Mark Twain
Willowdale, Ontario   |
Work: (905) 477-0437 Home: (416) 223-8968 Email: davecb at

More information about the samba-technical mailing list