How to NOT connect an SVC in a core-edge Brocade fabric

Good post by Sebastian Thaele (thank you)

In on of my previous posts I wrote about “Why inter-node traffic across ISLs should be avoided”. There is an additional “bad practice” that could lead to performance problems in the host-to-SVC traffic.

Let’s imagine a core-edge fabric. A powerful switch (or director) in its center is the core. The SVC and its backend storage subsystems are directly connected to it. Beside of that there are also the ISLs to the edge switches where the hosts are connected to. As there is an SVC in the fabric, all host traffic usually goes to the SVC and the SVC is the only host of all other storages. From time to time I see a cabling like the one below. The devices are connected in a common pattern. For example SVC ports are always on port 0, 4, 8, … or for a director for example on port 0 and 16 on each card… Something like that. The reason behind that is often to spread the workload over several cards/ASICs to minimize impact in case of a hardware failure. But there’s a risk in doing so.

Read on here

Leave a comment

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s