Solved

How to configure disks for databases and logs

Posted on 2007-11-26
10
218 Views
Last Modified: 2010-03-06
I am planning out the disk configuration for our Exchange 2007 server. It has a SAN back-end. I want to create LUNS for our Storage Groups and Databases. I will have four Storage Groups with one Mailbox Store in each Storage Group. I was going to put all Databases on a single LUN because that is the way our Exchange 2003 server is configured, but with or current server, I have only 1 Storage Group. Should I create a separate LUN for the log files for each Storage Group, or can I put all the logs from all 4 Storage Groups on the same LUN. It seems easier to put them all on the same LUN so I don't have so many different drive letters to deal with. Just wondering what everyone else is doing.

Thanks
0
Comment
Question by:osiexchange
  • 7
  • 3
10 Comments
 
LVL 19

Expert Comment

by:SteveH_UK
ID: 20353299
You might want to read http://msexchangeteam.com/archive/2006/04/07/424645.aspx

There isn't a real issue with combining the disks that hold data, as this is all random access.  Except, of course, if you want to backup them separately.

The logs would benefit from being on separate LUNs, but it really depends on the number of disk platters available, and therefore cost.
0
 
LVL 19

Accepted Solution

by:
SteveH_UK earned 500 total points
ID: 20353310
Another advantage of using separate LUNs would be to allow online migration of a LUN to a different storage device.

However, although I understand the disk issues, I have little practical experience of SANs so another expert's advice would be welcome.
0
 

Author Comment

by:osiexchange
ID: 20353428
Thanks for the articles. I will take a look at them. Our Raid groups on the SAN use a Raid 5 utilizing 8 physical disks. The only reason I did not want to go with separate LUNS for each Storage Group log disk is because it would create multiple drive letters which can get confusing.
0
 
LVL 19

Expert Comment

by:SteveH_UK
ID: 20353484
Agreed, but Exchange 2003/7 also support direct storage on SANs which performs better than file based approaches.

I'll look up the references...
0
 
LVL 19

Expert Comment

by:SteveH_UK
ID: 20353504
My mistake, you map them to a drive!

Are you using an iSCSI initator?
0
How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

 
LVL 19

Expert Comment

by:SteveH_UK
ID: 20353520
0
 

Author Comment

by:osiexchange
ID: 20354819
Yes, ISCSI initiator. Each LUN shows up as a drive letter under Windows. The more I think about it, having all the logs from all the Storage Groups go to a single LUN is not much different than what I am doing now only with local storage. I have a single Storage Group with 4 Mailbox Stores. All the logs for all 4 Stores go to a single spindle. The databases go to a separate spindle. I would think the advantage would be better performance however is each Store had its own log file LUN to write to. I'll check out that article.
0
 
LVL 19

Expert Comment

by:SteveH_UK
ID: 20356022
I guess it depends how many spindles you have in your LUNs!

Use RAID1 or RAID10 for the logs.   Use RAID5 or RAID10 for the data.

Whether you grow a LUN by extra spindles, or split the data/logs across more LUNs is up to you, but I would recommend the former as it will be easier to manage for changing environments, i.e. keep LUNs to store different types of data with differing access patterns.
0
 

Author Comment

by:osiexchange
ID: 20358492
Thanks. I am still not clear on whether to break out separate LUNs for log files and data stores. I think if we want to use LCR, we need to. With Four storage groups and a store in each storage group, that would be 5 individual drive letters if I put all the stores on a single LUN and 8 drive letters if I break out the stores to separate LUNS. FOr LCR, I can use mount points but still, 8 drive letters seems ridiculous.
I was just wondering what other people are doing.
0
 
LVL 19

Expert Comment

by:SteveH_UK
ID: 20360639
You don't have to mount partitions at the drive letter level, so I'm not sure why you need so many drive letters!

What I recommend is that you create a logical disk structure within a folder, perhaps in C:\SANDisks, and then map individual LUNs to folders within there, optionally using another level of structure to represent the type of data.

You can do this logical mapping in Disk Management.
0

Featured Post

6 Surprising Benefits of Threat Intelligence

All sorts of threat intelligence is available on the web. Intelligence you can learn from, and use to anticipate and prepare for future attacks.

Join & Write a Comment

Find out how to use Active Directory data for email signature management in Microsoft Exchange and Office 365.
This process describes the steps required to Import and Export data from and to .pst files using Exchange 2010. We can use these steps to export data from a user to a .pst file, import data back to the same or a different user, or even import data t…
In this video we show how to create a Distribution Group in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Recipients >>…
In this video we show how to create an Address List in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: First we need to log into the Exchange Admin Center. Navigate to the Organization >> Ad…

743 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now