SAN questions

By Anne Skamarock
Network World Storage Newsletter, 03/05/01

I received many responses from readers to my " Reason for urgency " newsletter (see www.nwfusion.com/newsletters/stor/2001/00408554.html). Thank you for your e-mail.

Many of you asked me about the software-enabling functions within a storage area network (SAN). " If the software is not complete, what is it missing? " was a common question I received, and a difficult one to answer. The reason it is difficult to answer is because I don't know your individual businesses or your priorities. Perhaps the SAN management software available today meets your needs, perhaps not.

Understanding what could be possible within SAN management software requires a thorough understanding of how a particular business uses data, and therefore storage. It also requires a bit of imagination. There are two levels of business-related questions that you need to ask yourself. The first are the high-level, " Do I require this technology at this time? " kinds of questions. If you decide that your business will benefit from implementing a SAN, then comes, " What do I require from a SAN? "

Some of the high-level business questions include:

* Is your business in a highly competitive industry?

* Are your open-systems data/storage operations running efficiently and effectively?

* Are you spending a large part of your IT budget on open-systems storage and storage management?

* Are you an early adopter of technologies? Can you afford not to be in this case?

Once you have decided to implement a SAN, the business IT environment will define the SAN requirements. The questions listed below are just some of the points to be considered:

* What quality of service do your business applications require?

* What are the " normal " uptime needs? How many hours per year can you afford to have your business applications offline because of failure or maintenance?

* What is the current storage run rate and expected run rate or need for storage?

* What are the data retention needs (these can be very long in some industries, such as the pharmaceutical or health care industries)?

* What are the disaster avoidance needs? If the main data center were to have a disaster, what would it cost you business for every hour of downtime?

* What are the existing server platforms that must be supported by a SAN? What existing storage platforms do you want to support, if any?

* How much internal expertise do you have within your own organization? How much are you willing to pay someone else to " just have it work " rather than supporting it yourself?

* How volatile is your environment? That is, how often does it change with new platforms, etc.?

* What management issues do you have today? Where is your greatest point of pain?

All of the questions above will help define what you require of a SAN today - but the most important questions have not been asked yet. What do you expect from a SAN? What would you like a SAN to do for you? The answers to these questions will determine whether the current software is capable of delivering those services.

Some of the capabilities you might want to think about are:

* Reduce the back-up window and make more efficient/effective use of back-up devices

* The ability to centrally manage backups worldwide

* The ability to share files

* The ability to share data

* The ability to add storage to a server without bringing down the system

* The ability to add storage to a server without bringing down the application

* The ability to use a high-performance/high-availability disk as the primary storage device and mirror to another, less-expensive device for fail-over

* The ability to copy data to another storage device while the application continues to run, for use with backup, remote copies and storage technology upgrades

* The ability to automatically move data to remote locations

You know your business better than anyone. What would create an open-systems storage environment of operational efficiency within your business? Try to be a specific as you can be.

After you have answered these questions (and many more) for yourself, prioritize your needs and ask your vendors if they have the capabilities TODAY. If they don't have them today, are they planned? If so, when? And, of course, how much will it cost?

There are many things a SAN could do - but not all of the functionality is available today and not all the uses have been dreamed of yet.