Every-time, as a consultant DBA, a customer ask me the question which RAID and why will fit best their needs. I tend to provide my experiences, my ideas and share but rarely it's enough.
In this blog entry I will try show exactly for one specific machine what will be the efficiency for each and individual RAID setup in terms of rough IO/S and MB/s.
Note that the tool that I have used is SQLIO, in a near future I plan to also re-do the tests with the tool Iometer. What is important to know is that the situation when I did the tests was ideal. The Raid Setup had been done then re-done according to the needs and there were no application and no user connected to the server during the tests.
The server used is a IBM x336 series with 16GB of RAM, windows 2003 x64 installed. The setup raid was local to the machine, the cache controller was integrated to the machine and its size was 256MB.
Following is the legend table to help you to interpret the different test cases scenario therefore will you find all the detail of each scenario that has been tested :
A. Result extracted for write performance :
B. Result extracted for write performance :
Result : As for the interpretation of the output we can clearly see that setup in RAID 10 is far the most efficient in regards our tests scenarios. For read and write instructions it has demonstraste to be faster quite significantly and that even though in the RAID5 setup we had 15k drive rather than the 10k when setup in RAID10.