Second Opinion please.

[simm0]

I am evaluating Veeam for my workplace and am generally impressed. Tests backing up a 250GB VM on an ESXi 4.0 host show SAN and Virtual Appliance modes to be reliable and perform well. However network mode is appalling, 3-4 MB/s. All three modes were writing to the same storage. I have contacted support regarding this issue and have been told that:

"However, performance in network mode is very dependent on your infrastructure, and in your case, speeds of 3-4 MB/s are normal."

Is this Veeams official stance on Network mode issues? To me 3-4 MB/s on a gigabit network which otherwise performs to expectations is not normal for any application.

[Alexey D.]

Are you talking about replication, not backup? Could you try copying files to the same datastore, using Datastore browser? What speed do you see?

[simm0]

Hi Alexy.

I am talking about backup. I have created a backup job and tested it with all 3 modes.
I am happy to perform the test you suggest. To be clear, you want me to copy from my backup storage (SCSI attached array hosted by a physical server) to the ESXi datastore where the VM's are stored?

[Alexey D.]

From ESXi datastore with VMs to backup destination (this physical server).

[Gostev]

Simon, you should copy from your production LUN locally to backup server.

I am not sure why would I want to do network backup though, if I had ability to use other backup modes (and you clearly are). Not only the performance is worse, but it also loads your management network and affects actual host itself (unlike direct SAN backups).

Anyway, network backup from ESXi is pretty slow, yes. More typical numbers is about 10MB/s, 3-4 MB/s is on lower end side (have been reported a few times before), I have also seen much faster speeds reported a few times (50-55 MB/s). I am fairly sure the differences are environment specific, but was never able to pinpoint the primary reason (I think it is specific to host hardware, but may be also physical network equipment and settings).

What you may try to do first thing is upgrading to ESXi 4.1. VMware had a bug in ESX 4.0 that resulted in abysmal network copy performance (there is huge topic about this issue here on this forum). This was fixed in ESX 4.1, and it is possible that the same fix affects ESXi 4.1 positively as well. If you decide to do this, please be sure to update us with your findings. We are very interested to know.

But again, it is very typical (almost "expected") for network backup to be slow. And as you will see after you test download speed with Datastore Browser, this issue is not because of our product

Thanks.

[simm0]

Ok, thanks to you both. I will try the test tomorrow at work.
I had read the thread on slow Network mode with ESX 4 but was not sure if it applied to ESXi also.
I do not want to do network backup at all but would like it to be an option if all else fails, we have a single ESXi host and a single SAN. Plus if something does not behave as expected I like to understand why, that's just my nature.
The ESXi 4.1 update is in the pipeline as soon as some downtime can be scheduled, that may not be for a week or so. I will let you know if it affects Network mode.
Thanks for the info, it helps this issue sit a little better with me.

[Gostev]

Good point, actually our product automatically fails over to network mode if for example direct connection to SAN is temporarily unavailable (although you can disable this behavior). This, of course, should not happen too often unless you let office cleaners into your server room however, still good to have this extra assurance that your backups will be completed no matter what. Thanks, and we will be waiting to hear updates from you.

[simm0]

Copy test completed as instructed. Transfer speed on par with network mode (hideously slow!), if anything Network mode transfers were marginally better.
I will update once the host is updated to ESXi 4.1.
Cheers.

[Alexey D.]

Ok, let us know.

[simm0]

I upgraded to ESXi 4.1 over the weekend. It has made no difference to Network mode or datastore transfer speeds, both are still very slow.

[Alexey D.]

What MB/s are you seeing now? Which were before?

One of your hardware components may be a bottleneck because of its performance / settings. Please check it. Normally there are improvements in speed after upgrading to 4.1