I currently have 460 users in Exchange 2007 sp2 with 230 in two storage groups each. I have one lun that contaims both databases and one lun for the log files. I will be adding another 600 users. The Exchange storage calculator says I need another three SGs for these users which is fine, but also one database per lun and one log set per lun so 6 more luns. I wanted to cut down the the amount of luns I need to manage and put these three databases on one lun and the t-logs on another so I would have total two database luns and two t-log luns on my server. Is it a acceptable practice to put more than one database on a lun?

Hi,Best practice is to look at the performance of the LUNs and make sure that the LUNs willsupport the number of users.Storage calculator will help here, but if the LUNs are located on the same physical disks it doesn't matter. Another thing is that some VSSbackup systems require that one database is placed on its own LUN.You can use the jetstress tool to test the disk performance once they are created.Leif

Thanks Leif for your response. With all the perf counters available, what in your opinion would be the best perf counter(s) to look at performace of the luns?Thanks, Alex

Alex-If you tweak the backup options in the storage calculator, it will change the recommendation for the LUN layout.This tool http://www.codeplex.com/PALhas an Exchange 2007 Mailbox profile which will give you a great report.Active Directory, 4th Edition - www.briandesmond.com/ad4/

Resources: Disk Utilization Percentage, Read Cache Hit Ratio, Write Pending Requests Storage Processor Utilization Percentage Configuring, validating and monitoring your Exchange 2007 storageJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com