Keep an eye on the free space there – you don’t want to create a test file that can run your server out of drive space. Just know that the bigger the test file, the longer it takes to generate. Smaller test file sizes may look fast but don’t really reflect how a large database will work. If you’re under the gun, do a quick 1GiB test, but for real go-live prep, I like using 32GB to reduce the chances that I’m just hitting cache and getting artificially fast numbers. If you want a fast seat-of-the-pants guess, do 1, but keep in mind it can be wildly variant between passes if something else happens to be going on in the SAN.
(I’ll be charitable and not tell you which one.) Instead, let’s get seat-of-the-pants numbers for your storage. It takes knowledge and time, and you only have one of those.
#Crystal diskmark how to#
I’ve written about how to test your SAN’s performance with SQLIO, but I’ll be honest with you: that’s the hard way.