EMR and Storage Area Networks (SANs)

Posted on May 2, 2006 I Written By

John Lynn is the Founder of the HealthcareScene.com blog network which currently consists of 10 blogs containing over 8000 articles with John having written over 4000 of the articles himself. These EMR and Healthcare IT related articles have been viewed over 16 million times. John also manages Healthcare IT Central and Healthcare IT Today, the leading career Health IT job board and blog. John is co-founder of InfluentialNetworks.com and Physia.com. John is highly involved in social media, and in addition to his blogs can also be found on Twitter: @techguy and @ehrandhit and LinkedIn.

A friend of mine on EMRUpdate recently asked how a SAN applies to EMR. I took so much time to write a response I decided to copy it here. I’m sure I’m missing some details, but this should be a good start.

Really a SAN is basically a bunch of disks that can be connected to a bunch of different servers over fiber optics. You can see more formal definitions at the Wikipedia – Storage Area Networks and Webopedia – Storage Area Networks.

My personal experience with a SAN is that they are fantastic, but they are quite complex to work with. They are getting cheaper and easier to manage(evidenced by a nice SAN product from Apple), but it still takes some work to get it working.

To me the real advantage of a SAN is that it allows you to do clustering. It separates your data from your server making the 2 independent of each other. This makes managing servers very nice(pull out a server and update it with no down time) and backups of the data(you can backup your data to disk and then from disk to tape).

So, why would an EMR want to use a SAN? Quite frankly most won’t want to right now. Purchasing a server with a bunch of hard drives is good enough for most small doctors offices. It could be very beneficial for very large offices that need to maintain 24 x 7 uptime and/or store a whole lot of data. A server these days can only reach about 1.8 Terabytes of data(6-300 gig hard drives). SANS can easily hit 7 Terabytes of data(and plenty more if you have the $$).

Sure, you can hook up a nice scsi shelf to increase the number of drives on a server, but then you get much slower response reading the drive through the scsi connection. Often they use the term “High Availability” when they talk about the speed with which you can access data on a SAN. Besides storage space, the speed with which you can access a large amount of data is what sets SANs apart from just a bunch of drives.

There are some other real nice features with SANS, but these are the main ones in my mind. As they get cheaper and EMR’s databases get bigger I see them becoming a larger part of an EMR system. Until then, no need to worry about SANs with your EMR.

As far as “Why do they call it a “Storage Network” instead of just “storage”?”

I think the terminology “network” is applied because you are connected to the SAN(or storage) using fiber optics and you go through a fiber switch to enable fast access to the drives.