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flooble
Asked: 2010-12-13 06:35:20 +0800 CST

Flow Control - Where do you enable it?

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In the testing/playing phase with a bunch of new SAN/Server kit.

I have 2 x Procurve 2910 switches dedicated to iSCSI/vMotion (with a 10gbps fibre link between them), 2 x vSphere hosts (each with lots of NICs), and 6 x P4000 iSCSI nodes.

The P4000 manuals say to enable flow control on the switches.

I'm not clear if that means enable it globally, or just on the ports that the P4000 nodes are directly connected to?

I'll be mounting iSCSI volumes from both the vSphere hosts, and from within some of the guests (Windows 2008 DSM MPIO).

I know what flow control does at a basic level, but I don't know enough about it at low level to know where I should be implementing it.

Thanks.

networking iscsi vmware-vsphere

1 Answers

  1. Best Answer

    Per port should be sufficient provided you are covering all of the iSCSI connections to the switch - that's both those connecting to the P4000 nodes and any to hosts that are consuming the traffic. In most cases though enabling it for the entire switch would be desirable because you want Flow Control operating for all ports handling iSCSI traffic. If you have any devices that can't handle flow control then try to fix that or move them to a separate switch if possible. As Tom said in his comments most Nics will have it enabled by default.

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