More Microsoft Pro-DAS Jihadist FUD (and a counter)

Mr Perry Clarke has been at it again. http://blogs.technet.com/b/perryclarke/archive/2010/11/16/responding-to-migration-vs-in-place-upgrade-comments.aspx is his latest pro DAS, anti Virtualization and anti networked storage communique. This follows on from: http://blogs.technet.com/b/perryclarke/archive/2010/04/14/storage-performance-and-my-take-on-virtual-storage.aspx which has been taken apart in a number of forums over the past few months so I won't bother doing so here. It's getting to be depressingly routine but so long as he keeps saying things I get to talk to customers to tell them why you don't do something "just because" Microsoft tells you to and "just because" a Microsoft employee proffers an opinion.

If you want a strategic solution you put enterprise networked storage into your data centers. Depending on what your business requirements are you implement such a solution from one or more vendors. EMC and NetApp will tell you, it's all about your business and what business problem you are trying to solve and what service you are trying to deliver to the rest of the business to enable them to work more efficiently and with greater productivity. You don't abandon a strategy "just because" an employee at a company who doesn't do storage says one of your applications should be done the way he likes. Thinking in a silo'd manner is several years out of date and the Microsoft Exchange product group do themselves a gross disservice by continuing to do so. Please, if you see something from them that says anything other than "large, low cost mailboxes" or you encounter a sales rep or MCS consultant that says anything else or recommends DAS please email me with their name and you can be hooked up with the official line, direct from Microsoft. (I won't even get involved!)

Similarly virtualization is a solution to a business problem. Do it or don't do it, it doesn't really matter to me as an applications professional working for a storage company. But if you do implement it there are some things you are going to want to think about. If you do implement a virtualization platform there's a good chance that your requirement for a highly available infrastructure didn't just go away. There's every chance you want both. There's every chance you want to have highly available guest servers as well as a highly utilized host server environment. So would you put the data onto disks internal to the host? Sure, if your guests had no high availability requirement. But only if. If you need that data highly available you're going to store it on a networked platform. Of course, if you have two hosts and put a DAG guest on each and a load of disks you're getting that HA but you still don't get storage efficiency and lost flexibility as well as being constrained into buying hardware that can take lots of internal disk. And who in the enterprise is buying big iron servers for little silo jobs these days? If you have a couple of servers and that's it then yes DASDASDAS. If you need a dozen or more server names and isolated roles then a blade farm is going to be an attractive option to you. Again, more with the business requirements and strategic direction. Good luck with running Exchange and DAS in a Hyper-V blade host.

NetApp commissioned and released a document:
http://media.netapp.com/documents/esg-wp-netapp-exchange-storage-efficiency.pdf on, as the file name suggests, storage efficiency. It talks about what to look at when calculating the TCO of an Exchange environment and little of it has anything to do with the data inside the EDB files.

Remember what a showcase from Microsoft is. Remember what it is not. It is a "how we did". It is a "how we, with unlimited resources and an inability to use anything other than Microsoft software solved a business problem". It is not a reference architecture. It is not a prescriptive set of steps to follow to generate the perfect environment. If you or your staff have printed out a showcase then you are already in trouble and your business is ready to spend more than it likely needs to.

Bottom line? Think about it. Microsoft release a good application with their Exchange product but those people aren't paid to look beyond the application and you would do yourself a favour if you put anything they said to one side of your desk and got the other side of the story from your infrastructure architects.