SQL Databases – Hard drive killers!!

Just happened again today… A client brought us a hard drive for data recovery approximately 2.5 years old, they have been using it in their server to host a SQL database.  The server had been experiencing slower than usual performance in recent weeks and then 2 days ago the drive was not available to the server.

SQL, Structured Query Language, is a database programming language used to manage information in a relational database.  It is a widely used application that manages tens of thousands of websites across the world, customer relationship applications, and many other types of applications.  SQL databases are the underpinning of more applications than you might realize.

Database files are almost always contained in contiguous space on a hard drive, that is to say the entire file is one location.  Just like the carpet in your hallway, the sectors of a hard drive “wear away” in areas of more frequent traffic.  So, if you are constantly reading and writing information to your SQL database (or really, any kind of database) you are wearing down the ability of your hard drive to work in that area.  All this traffic can ultimately cause the hard drive to fail.  damaged platterThe real question is, can we recover your database?  It all depends on the severity of the failure.  If we get the drive before it is too bad we can usually get a good working copy of your database.  But, if the drive is left to run too long, the read/write heads can actually wear a concentric groove into the platter where your database used to live.

 

As I mentioned, this phenomenon is not limited to just SQL databases.  We just happen to see more drives with SQL databases than any other type of database. But, if you are using any kind of database or an application that uses an underlying database you could be at risk too.

 

The best way to prevent this type of hard drive failure from happening is to proactively replace your hard drive(s) on a regular basis, especially those containing databases.  If you can’t replace your hard drive proactively, using a database “aware” backup application will at least prevent you from losing too much work.