SQL Server Performance Forum – Threads Archive

Multiple databases on same drives

If I have created two databases that will be used by my employees randomly. Can I put the data files on one disk array and the log files of both databases on a seperate disk array using a total of 2 arrays? What if I split them all up on multiple arrays, will that give me better performance or am I fine as long as data files are on one array and logs on another? Would there be any performance gains by using Example B: (All drives are the same speed)

Example A: Drive 0
Database 1, sample1.mdf
Database 2, sample2.mdf Drive 1
Log 1, samplelog1.ldf
Log 2, samplelog2.ldf Drive 3
Operating System
MSSQL Drive 4
TEMPDB
Example B: Drive 0
Database 1, sample1.mdf Drive 1
Database 2, sample2.mdf Drive 2
Log 1, samplelog1.ldf Drive 3
Log 2, samplelog2.ldf Drive 4
Operating System
MSSQL Drive 5
TEMPDB

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Example B could give better performance as you will be dividing the load over multiple drives. In A, both reads/writes for both databases when accessed simultaneously will be on the same drive, and even though different files, can cause I/O bottlenecks. In B, the read/writes is spread over different drives giving better perforance. ***********************
Dinakar Nethi
SQL Server MVP
***********************
http://weblogs.sqlteam.com/dinakar/

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thanks. Do you know anything about tempdb? It has a log and data file. Should I split those as well or are they fine on the same array?

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Better to keep it on same array but different from user databases,http://sqlserver-qa.net/blogs/tools…r-2005-index-optimization-best-practices.aspx fyi. Satya SKJ
Microsoft SQL Server MVP
Writer, Contributing Editor & Moderator
http://www.SQL-Server-Performance.Com
This posting is provided AS IS with no rights for the sake of knowledge sharing. The greatest discovery of my generation is that a human being can alter his life by altering his attitudes of mind.

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