I can’t comment on specific feature enhancements or firmware updates, so I will try to address your comments as best possible in those areas.

Yes, there are some profile related annoyances noted by Rob and Scott. Originally Virtual Connect had the ability to change network mappings on the fly without powering off the blade. But with a recent flurry of Virtual Connect enhancements including Flex10, some of those features were temporarily disabled. We have added tons of enhancements over the last 2+ years, and I expect that you will see positive changes in the areas you noted.

With regard to VLAN tunneling (multiple networks per FlexNIC), I have worked with VC and Flex10 extensively but have not come across many customers interested in tunneling large numbers of VLANs across a single FlexNIC. Obviously there is nothing wrong with doing that, just that experience has shown limited interest in that type of design. It would help to understand that VLAN strategy a little better to be able to comment more appropriately.

Experience with VMware customers using Flex10 has shown that most are using a smaller number of VLANs to support VMs running on an ESX farm, and that Flex10 provides greater bandwidth and better LAN fault tolerance for VMware environments than was previously available. The big thing here was increasing the number of physical NICs presented to the OS and simultaneously increasing bandwidth (regardless of OS or application) – and at the same time lowering core uplink and edge interconnect costs.

With respect to the limitations on SmartLink, there is logic there which requires a more detailed design discussion to fully address. Suffice to say that rules/reactions are different for FlexNICs with mapped (Single VLAN) and tunneled FlexNICs (Multiple networks). The SmartLink rules depend specifically on how your uplinks to the data center are configured, in addition to your VLAN selection on the FlexNIC. These need to be planned for on a customer by customer basis.

I will keep posting as time allows.

In this article you said: “you have the ability to fine-tune the amount of bandwidth allocated to each of these FlexNICs, up to the shared maximum of 10Gbps.”

Question: Is the “Allocated” bandwidth for a FlexNIC a maximum not-to-exceed bandwidth? Or, is “Allocated” bandwidth a minimum guaranteed bandwidth with the ability to go higher if bandwidth is unused/available?

In other words, suppose I have (2) FlexNICs on the same LOM port, each with an “Allocated” bandwidth setting of 5Gbps. If FlexNIC #1 is idle, not using any bandwidth, is FlexNIC #2 able to use 10Gbps? Or, in this scenario, is FlexNIC #2 still limited to a maximum of 5Gbps?

Thanks,
Brad

Thanks for adding your comments! I appreciate it. To help further drive home your point about presenting multiple VLANs to the FlexNICs, I’ve posted this follow-up:

http://blog.scottlowe.org/2009/07/09/follow-up-about-multiple-vlans-virtual-connect-and-flex-10/

Thanks again!

Thanks for taking the time to evaluate Virtual Connect. HP’s Virtual Connect with Flex-10 enables our customers to use VST on all FlexNICs providing they use different VLANs on each FlexNIC LOM. Replicating FlexNIC configurations between LOMs allows for teaming and chip-level redundancy. There is no advantage to using the same VLANs one each FlexNIC beyond the additional bandwidth; something easily tuned using the bandwidth parameter on each individual FlexNIC.

Another alternative to mapping a VLAN to independent sets of FlexNICs for Console traffic and VM traffic would be to define two different Virtual Connect networks, one for service console traffic, and the other for the VM traffic. Virtual Connect will keep these two networks completely isolated, but you can bridge them externally. In many cases, it is desirable to keep those two separate anyway.

Thanks again, we look forward to more insight.

Chris

I do not know if there are similar limitations with VLAN tunneling. That is on my test plan, so I’ll post results here as soon as I have more information.

Does this scenario only happen with VLAN mapping or does it apply to VLAN tunelling as well?

Thanks for the additional information. I was already aware of the need to have a server powered down in order to modify the Server Profile, but it is helpful to point that out again. If there is one limitation that HP most needs to address, it’s this one, IMHO.

Similarly, the limitations on the number of VLANs and the number of VLANs that can be mapped to a single FlexNIC could similarly be problems for larger environments.

As for the Smart Link limitation (not being able to take down a single FlexNIC), I don’t see that as a limitation–that makes sense to me. If an uplink goes down, you would WANT all four FlexNICs to go down because they all ride the same uplink (or same set of uplinks).

Thanks for your comment!

Let me fill you in on a few other limitations of Virtual Connect and Flex-10 right now.

If you need to make any changes to a server profile like adding a VLAN or adjusting the bandwidth of the Flex NICs you have to reboot the host. It is an issue in our environment where we have many VLANs and having to add one to an ESX host to support a new VM is not unusual.

The previous Virtual Connect firmware version had a limitation that you could only map up to 32 VLANs from an uplink set. Again we use many VLANs and were bordering on this limit. The new firmware has increased this to 64. But the other limitation of the previous firmware is that you could map up to 28 vNetworks(VLANs) to a single FlexNIC. We have not got confirmation from HP that this number has increased with the latest firmware.

Virtual Connect can’t take down the link of an individual FlexNIC, it can only take down the link of the whole physical NIC(all 4 FlexNICs). This is a problem if you use link status to do ESX network fault tolerance. Virtual Connect has a feature called Smart Link that if a Virtual Connect uplink goes down it will take down the server links. But again it can only take down the whole physical NIC and only if the all uplinks for all the vNetworks that are mapped to all 4 FlexNICs go down.

I know HP is aware of some of these limitations and has stated they will be addressed in future firmware releases.