Introduction - VMware’s impact

My point of view is based on what I’m doing daily - consulting SAN projects in their presales phase and leading SAN installations in a storage reseller company in Czech Republic (EU). The first thing coming to my mind on this topic is that most of the storage stuff today is somehow being requested for or compared to VMware:

• People request a storage system to be installed with VMware or at least that it should be supported by or able to connect to VMware later.
• People ask for SAN features comparing them to what VMware does with servers: high availability, hardware abstraction, central management or DR capabilities.

For administrators, VMware usually means fewer worries and more safety. They are happy hearing that they can get similar features at the storage layer. For us, the reseller, it’s a good tool to compare SAN features to VMware since so many people have already accepted it. Selling a synchronously mirrored array is much easier after comparing the transparent failover capability to VMotion known from virtual servers.

Simplicity - It’s Not Laziness

I feel simplicity is turning out to be a strong attribute of SAN solutions. It’s not because of lazy administrators. It’s because simplicity brings more safety to people operating SANs.

There are many different systems and they are changing often, so administrators are forced to learn how storage, servers, networks communicate and affect each other globally — without being able to deeply understand a system. There’s not always enough time for details. People in IT are not cheap and so they’re often expected to sit on many seats.

In such an environment, running a “traditional”, complex storage system with all those hours managing configurations might be dangerous. Yes, there is outsourcing. But there is also the cost cutting. Which one wins? The simple, yet full-featured storage.

I believe simplicity brings safety to administrators’ work. Not having many options on how to set a system means not having many ways to do it wrong. Defining a new LUN in “traditional” storage systems requires a deep understanding of chunk sizes, raid operations, caching etc. Luckily there are vendors who moved these decisions closer to “simplicity.”

The more we think about high availability, the more we should think about simplicity. It’s hard to maintain a complex storage system that is always ready for failover. In many companies running some sort of HA solution, administrators are not sure that their system will survive a failure. Usually it is because there are many settings and many conditions for failover to succeed. If any one fails, the whole failover operation fails.

There is another attribute for extending or realizing simplicity: automation.

Automation - Intelligent Performance Manager

In my opinion there is a big space in storage systems which can be filled with automation features. Any storage array has lots of information about the data it stores and about the traffic it serves. It can perform lots of optimization features automatically.

A brief example: There’s an array with mixed SAS and SATA drives. There is a LUN with database data placed on SATA drives. The array is able to recognize the random traffic pattern and move the database data to SAS drives which can serve it faster. Or it can move just those blocks being accessed randomly, not a whole LUN. It can even adjust the chunk size or raid level after some period evaluating the traffic. On the other side - after recognizing sequential traffic - the array can communicate with the SAN client and aggregate network paths from array to client to increase throughput. Let’s call it IPM - Intelligent Performance Manager ;-)