So I have a SAN connected to VM hosts using a 100mb CISCO router. Apparently this results in a maximum data transfer rate of 12mbps, which is very poor.

There is full redundancy between the SAN and the hosts using 2 switches which are HP ProCurve 2910al 24g models.

I am lead to believe that these switches support some form of routing, so that essentially I could set a switch as the default gateway for the SAN Storage Processor A, and the second switch as the default gateway for the SAN Storage Processor B - is this correct and, if so, please can someone explain it to me like I am 5?

Essentially I want to utilize existing kit to get the best possible data transfer speeds between the SAN and my hosts.

Edit: a bit more info about the connectivity in the network:

SAN: 2 storage processors, A's IP is, B's IP is Management network for SAN is part of the LAN range

VMotion and iSCSI traffic are completely isolated - there are two HP 2910al 24g switches that carry the VMotion and iSCSI traffic between the hosts and SAN.

We then have 2 Cisco switches carrying the LAN and VM management traffic on the range.

At the moment, we have a router sitting there connecting the to the range so that we can manage the SAN. This effectively has 2 IP interfaces, one with the IP and one with the IP

The SAN and VMK ports have a default gateway of (the router). We don't currently use any VLANs at all (in the entire network).

For background info, I took over the whole sysadmin team about 18 months ago. The infrastructure was/is old and I'm trying to drag it kicking into this century. We've virtualised, but i'm on the VCP course this week and it's giving me some real thoughts about best practise, leading me to believe the current routing arrangement is a huge bottleneck and is probably wrong.

  • 2
    Why is you SAN traffic being routed at all? Can't you simply make your servers be on the same VLAN? – Zoredache Oct 17 '12 at 20:13
  • Mainly because I don't understand networking fully (which is not a great start, I'll admit). I can VLAN the traffic, but then I don't know what IP to use as the default gateway in the SAN config. – darth_phoenixx Oct 17 '12 at 20:18
  • You simply wouldn't need any Default Gateway because the traffic would never leave the VLAN. – Dan Oct 17 '12 at 20:19
  • OK, thanks - I'll try that out (UK-based so the office is closed and I'm not changing it remotely!). – darth_phoenixx Oct 17 '12 at 20:21

Don't do this - you should have a dedicated storage VLAN and then assign this VLAN directly to servers / NICs as required. Then you won't need any routing or a gateway. This also leaves you scope to safely configure jumbo frames and flow control etc as required, while keeping your storage traffic isolated from other potential networking issues on your production VLAN.

  • Thanks for responding. So, if I use for example VLAN ID 10 on the relevant ports on the switches, set the VLAN ID of the VMK ports on the hosts to 10 and set the SAN VLAN to 10, it will all just connect up? What about the default gateway in the network config? Currently, this is the router IP address. – darth_phoenixx Oct 17 '12 at 20:20
  • Essentially yes, no Gateway required anywhere. Can you edit your question to provide more detail about your Virtual Environment and its connecivity as it stands. – Dan Oct 17 '12 at 20:24
  • Thanks - updated original question with more info re: current connectivity – darth_phoenixx Oct 17 '12 at 20:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.