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Smart Zoning and UCS for ISR

Everybody is resting and recovering from a week at Cisco Live. I’m recovering from a week at Microsoft Tech Ed in Orlando, Florida. I had the privilege of talking to customers at Microsoft Tech Ed about our new Cisco UCS E-Series x86 blades for the Cisco Integrated Services Router (ISR). The Cisco ISR is our branch office router line that comes in fixed configuration and modular configurations. The ISR is commonly used to consolidate branch office services. The Cisco UCS E-Series brings serious x86 power to the modular ISR models further consolidating branch devices into the router itself. The E-Series even supports VMware and Microsoft Hyper-V bringing virtualization goodness at the branch. A common configuration is to load a simple Windows Server Core onto the E-Series with read-only ADS in case you lose connectivity to the main office. But that’s just an easy example. The E-Series has many more uses, and our customers are discovering more every day. If you are unfamiliar with the Cisco ISR, check it out, it’s a great product for branch offices.

Getting back to some of the goodies announced at Cisco Live. With NX-OS 5.2(6),  MDS customers get a new feature called Smart Zoning. In order to discuss what Smart Zoning is, we need to talk about zoning in general and today’s best practices in zoning.

Today when we set up a zone on our SAN, all devices within a given zone can talk to any other device in the zone. While this is all well can good, in large SAN environments it can lead to the depletion of a hardware memory resource known as ternary content addressable memory or TCAM. Every device in a zone takes up a TCAM entry and multiple large zones can use up TCAM. In order to get around this, today many large SAN administrators do 1 to 1 zoning. With 1 to 1 zoning two devices are both assigned to a single zone by themselves. This preserves TCAM resources by excluding all the other possible devices that could be in that zone. But this comes at a price. With so many zones it becomes onerous to keep track of them all and even simple storage changes may require yet another zone change. Storage administrators spend too much time maintaining and documenting zones with the 1 to 1 model.

With Smart Zoning, you can establish a one-to-many relationship between devices. Thus a single storage target with 20 servers connected get only the connection between the storage and the target, not the additional server to server SAN connections that happen with traditional zoning. This allows SAN managers to create larger zones, based on task without worrying about depleting TCAM resources. However the big savings comes in administrator time. Instead of creating multiple 1 to 1 zones, administrators can now use a smart zone and with a single command add a member. A more logical zone structure emerges as well, more closely aligned to the application/cluster.

These features are available in NX-OS 5.2(6) and can be enabled on a per-VSAN basis on the MDS product line. Check it out, it could save your company time and help simplify the SAN network.

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