Have you ever achieved more than 1 Gbps of network traffic into one backup server, over Ethernet?

[Support_User]

Have you ever achieved more than 1 Gbps of network traffic into one backup server, over Ethernet?

I am backing up 8 servers to one backup server.

I am trying to get more than 1 gigabit per second over Ethernet (to disk only, fast hardware, etc).

I have 2 x gigabit NICs in my backup server.  I have gigabit NICs in each server being backed-up.

I have 4 backup jobs set to use one NIC, and the other 4 set to use the other.

Although both NICs are getting used, my combined NIC traffic NEVER goes beyond 1 gigabit per second.  So, if I start the 4 jobs on the one NIC first, the traffic on that NIC easily maxs out at 1 Gbps.  Fine, that is expected.  Then, when I start the other jobs, I might see the 1st NIC's traffic drop to 600 Mbps and the 2nd NIC run at 400 Mbps.  Or, it might be 700/300, or 300/700.  This is very odd.  This doesn't SEEM to be network related. 

Is this some Backup Exec limitation?

Note: I have also tried creating a 2 Gbps Etherchannel, but I will stick with the above configuration for the purposes of troubleshooting, as it is one less thing to 'get right'.

[Ken_Putnam]

If both NICs are attached to the same switch, and if the switch has a 1GB backplane, that would result in what you see. 

That is 1GB through the switch is all you can get, total

[Support_User]

Do you know of anyone ever having achieved more than 1 Gbps over Ethernet?

Switch is Cisco Catalyst 3750, 32-Gig fabric, so definitely miles away from reaching that limit.

Cheers,

Nathan.

[frivers]

You won't ever achieve 1 Gbps over Ethernet due to the communication overhead of TCP/IP.  You'll have to switch to Fibre Channel to get that type of performance.  You don't really get 700Mbps network performance during backups.  That figure is just Symantec dividing the job throughput by the elapsed time.  I think a real world figure is around 66 Mbps while 100Mb ethernet tops out at 8 Mbps. 

Do your NICs have a TOE engine?  This may help you get more performance. 

[boff]

There are some other issues to look at.
The 2 NICs on your server may be sharing the same hardware interrupt, or have some other physical limit imposed by your hardware. You really need to benchmark your acheivable throughputs before looking at what you get in the 'real world'. A great tool for this is iperf. You can use this to generate tcp traffic from clients to hosts and figure out your max possible transfers. iperf doesn't read or write to disk so will give higher figures than you could get for a backup job.
Given your choice of switch I would strongly suggest using Etherchanel or LACP, it'll make your BE config easier as well.
Regards,
Julian

[Support_User]

Hi guys, thanks for your answers, but I am not trying to troubleshoot the server etc, as I can get more than 1 Gbps on this server using Windows Explorer to pull fies from other servers (should have mentioned that earlier and saved you the effort).  All servers on single LAN, gigabit switches with huge backplane speeds.

I am only interested in knowing if you have ever seen more than 1 Gbps combined job throughput on Backup Exec, pulling data over Ethernet, as Backup Exec seems to choke at that speed.  I am beginning to suspect nobody has done this - surely someone must have!

Symantec: is Backup Exec capable of doing this?

Not sure why I am asking, since Symantec have only ever tried to point the finger and have not once ever understood a single thing I've asked them.  And they are SO rude to me on the phone.  I would love someone from Symantec to prove me wrong!  Just once...please....

[Ken_Putnam]

All BackupExec is doing is read-write-read-write  etc, so as long as the CPU is not maxed out and as long as the network itself will support high throughput, BackupExec shouldn't  be the limiting factor

Message Edited by Ken Putnam on 02-13-2008 08:58 AM