Question

I have been working on ASP.net MVC3 Web application using MSSQL 2008 R2 for an e-commerce application – based on NopCommerce. We have created some temporary tables for executing some SPs in MSSQL as well. It is hosted on Windows Server 2008 R2.

Sometimes site starts to give lot of SQL timeout errors on different line locations for different pages.

We were taking a daily backup on the same drive where site is hosted. We noticed that only 18-20 GB Free space were remaining when the SQL timeouts errors were on pick. We’ve cleared some space and free space is appx. 60GB on the same drive.

To my surprise, Timeout errors were suddenly disappearing from the site.

I tested it for 2 times and it seems that the SQL timeouts errors were caused by lesser free space left on drive, and when we cleared few space the errors does not occur as earlier.

My Question is:

1. Does the space on hard drive where asp.net application is hosted does matter for performance of the site?
2. If it does, is the c: drive is used or d: (in our case the application is hosted on some folder on d:)
3. How to arrive at the optimum free space requirements?

Any docs/links would be nice to understand this.

Thanks in advance.

Answer 1

1. As you indicated in your question, it’s the database more than ASP.NET that will slow down as your disk fills up.
2. It depends on how your SQL database is configured. If you use the default SQL Server installation, it will be on the C drive, but you can configure a database to span multiple disk drives.
3. According to the article below, 85% full is the point where you’ll start to notice a significant decline in performance from SQL Server.

http://www.simple-talk.com/sql/database-administration/estimating-disk-space-requirements-for-databases/