Hi I am going to be setting up a 2 node (active/passive) single DAG on SAN storage for 14k users on Exchange 2010. Using the Exchange 2010 Calculator it recommends using RAID 1/0 for the Database and Logs on 8 x 2TB LUN. I am wondering would I get away with using RAID 5 for the Database on the SAN storage? or should I use RAID 1/0 ? (cheaper if I can use RAID 5) I can't seem to find what the recommend SAN RAID config is on SAN Storage for Exchange 2010 Thanks ECL

Hi, I will suggest you to read these articles and you will get your answer. http://technet.microsoft.com/en-us/library/ee832792.aspx http://msexchangeteam.com/archive/2010/03/29/454443.aspx I hope this will help you. Regards. Shafaquat Ali. M.C.I.T.P Exchange 2007/2010, M.C.I.T.P Windows Server 2008, M.C.T.S OCS Server 2007 R2, URL: http://blog.WhatDoUC.net Phone: +923008210320

So before we get to the RAID configuration...a few comments. 14K users on one server (you say two node active/passive) seems pretty high density. I guess it depends on your user profile. 2nd comment is sharing a SAN for the DAG. In my opinion, there is not much benefit putting both of your database copies on the same disk subsystem. If you want to have multiple copies, I recommend strongly splitting your database copies to different disk subsystems. Doesn't mean you can't use your SAN for one of the copies and use DAS for the other copy. With a user base your size, you really need to use the Storage calculator to get a proper storage design. There are options for different RAID configurations. What type of RAID you use depends on what your IOPS requirements are. What kind of CPU and RAM requirements is the calculator spitting out for housing all 14K users on one node? Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

Hi Tim, I used the storage calculator. The spec is 8 Core / 128GB ram. and IOPS is DB 1680 / LOG 370. Disk is 6 x 2TB LUN, 6 x DB with 2333 users on each DB. 14k users / 100 msg per day. One thing I forgot to mention is each node will be in a separate data center with separte SAN storage. The thing about the storage calculator is it always recommend RAID 1/0. But since Exchange has less IO overhead than previous versions I would of expected RAID 5 to be good enough but MS seem to recommend RAID 1/0 ? So just after what others have used when using SAN. Thanks ECL

Hi Tim, Just been playing around with the exchange calc and found if I changed the spec of my disks to 10K RPM it let me use RAID 5 for DB :) What do you think about 2333 per DB? Thanks ECL

The question is does your storage meet the IO requirement of your User profile? Also, what is the CPU utilization the calculator is giving you. On the Storage tab of the calculator, there is a "+" sign along the left. Click it and it will show different RAID configurations and IO/Capacity requirements. Since you are throwing all DB on one server, you need to look at IOPS per server, not per database. Exch 2010 is meant to scale horizontally and not vertically. Building up your server in density will work, but you are most likly going to have some performance hits with 14K users. I have not replicated your numbers in the calculator, but my suggestion would be to add another server or two to the DAG and spread out your users. You can probably buy 3 servers with 32-64 GB RAM and 8 cores as cheap as your single server with 128 GB RAM and however many cores to meet the IO. Plus you do not have local HA in your case. That is just my two cents (take it for what it is worth). Scale out, not scale up. You will have more flexibility and better overall performance.Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

Hi Tim, The CPU utilisation is 77% (just below the 80% threshold) - do you think that is too borderline? or shall I go for 12 core and that give 55% The IOPS is DB 1680 / LOG 370 per server based on 100msg and the calculator lets me use RAID 5 if I make the disk at least 10K RPM. However, I can't seem to find the "+" on the "Storage Design" tab you are talking about - it is near the top or bottom of the page? I did look at using JBOD and more servers (which works out cheaper than SAN) but management wants to use as least servers as possible due to space and support costs. Thanks ECL

The CPU is running pretty hot. I would go with 12 cores in this case. The "+" sign is along the left hand side of the page. Middle of the way down (left of the first column in the gray area).Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

Hi Tim, I found the "+" thanks and theres are lot of info there.... :S It says; Base Total DB IOPS 1680 Base RAID-5 Total DB IOPS 3696 Recommended RAID-5 Total DB IOPS 7392 I notice the 1680 is the same value as that in the "Role Requirements" tab in the "Total Database Required IOPS" section. Then I presume if I use RAID 5 then the IOPS I need is 3696 but the recommended it 7392 .. is that what it means ??? I am bit confused now. Since it lets me select "RAID 5" if I changed the RPM of the disk to 10K+ does that mean its OK or not? Also some parts of the "DB RAID Configurations" is in Orange do you whys that? Thanks ECL