Storage

Three storage features eliminated from Exchange 2010

Exchange 2010 eliminates several staples from the Exchange diet and for good reason. Learn which three major storage-related features didn't make the Exchange 2010 cut.

Exchange 2010 is a significant upgrade from Exchange 2007 and Exchange 2003, yet along with the product's new capabilities, there are a few major changes. Microsoft has removed what used to be key features of Exchange in this latest product iteration. In this article, I explain what's changed and how it might affect your upgrade planning.

So long, single-instance storage

Long a staple of the Exchange world, single-instance storage was ideal for the enterprise when storage costs were sky-high. These days, with storage costs so low that the amount of data being racked up multiples on a regular basis, Microsoft has traded storage space for overall storage performance.

In Exchange 2007, when a user sent a message with an attachment to 1,000 users, only a single copy of that attachment was stored in the Exchange database; pointers were then used to point individual mailboxes to those shared attachments.  With Exchange 2007, Microsoft took the first steps toward the eventual elimination of single-instance storage by not "single-instancing" message bodies. Prior to Exchange 2007, everything -- messages and attachments -- was single-instanced.

Over the years, the capacity of new hard drives has gone through the roof, whereas overall disk performance has accelerated at a comparative snail's pace. Exchange 2010's capacity vs. performance choice falls squarely on the performance side of the equation with significant improvements in overall I/O being the result. Another result is that Exchange 2010 supports a broader array of storage devices, including less expensive SATA disks. However, this also means that each time a user sends out a message with a 10 MB attachment, you can truly multiply that message size by the recipient count as the overall impact to the database size. To help counter this issue, Exchange databases are now compressed, at least to a point; messages headers and bodies are compressed but attachments are not.

Planning impact: Make sure you plan for adequate storage and understand that you now pay for each and every byte or each and every message and attachment. Exchange 2010's support for SATA disks should help keep costs in line.

Adios, storage groups

With the introduction of Exchange 2010, Microsoft has done away with storage groups. This doesn't come as a surprise; after all, under a number of high-availability scenarios in Exchange 2007, you could have only one database inside a storage group anyway. Remember that in previous versions of Exchange (including Exchange 2000, Exchange 2003, and Exchange 2007), storage groups were the level at which transaction logs were stored for the individual mailboxes databases stored inside the storage group. With the elimination of storage groups, each database now gets its own transaction log as well. To go along with this change, mailbox databases are now managed at the organization level rather than at the server level, and databases can be mounted on any available mailbox server.

Planning impact: Overall storage design planning is simplified with no need to try to figure out which mailboxes databases to place in individual storage groups. Long-term administration is simplified as well.

Sayonara, complex high-availability options! Hello, database availability groups!

Exchange 2007 introduced a variety of high-availability options, from local replication to availability and redundancy options that could span data centers. While these were very welcome additions at the time, Exchange 2010 eliminates them in favor of a new feature called database availability groups (DAGs).

DAGs make it far less complex to create highly available Exchange architectures that live in a single data center or span data centers across the globe. DAGs support up to 16 copies of your Exchange databases and handle much of the complexity of Clustering Services in the background and, even then, DAGs only use a subset of the full Windows Failover Clustering service, simplifying administration. Further, at install time, you don't need to worry about whether you're running a standalone mailbox server or a clustered mailbox server since any mailbox server can be made a member of a DAG at any time.

With Exchange 2010's improvements, Microsoft has also increased the maximum recommended clustered database size from 200 GB to 2 TB; this means that you can run your operations with fewer databases, which, in turn, means less ongoing administrative effort.

Planning impact: A fully redundant Exchange 2010 infrastructure can be accomplished with as few as two servers, while the equivalent architecture under Exchange 2007 requires four. Redundancy does not need to be planned ahead of time; it can be added at any point.

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About

Since 1994, Scott Lowe has been providing technology solutions to a variety of organizations. After spending 10 years in multiple CIO roles, Scott is now an independent consultant, blogger, author, owner of The 1610 Group, and a Senior IT Executive w...

4 comments
fisico
fisico

Muy clara la explicaci?n y nos ubica perfectamente en estas mejoras que deberemos de tomar en cuenta, muchas gracias.

CharlieSpencer
CharlieSpencer

Scott, you forgot one huge impact of the loss of single-instance storage. Increase storage means one's Exchange backup solution must be re-examined. Do you know if the long-planned elimination of Public Folders will occur in E10? Thanks; good article.

Kumaran
Kumaran

Removing Single Instance Storage is a Disaster and adding a compression feature and not compressing those multiple attachements makes it even more worse. While most of the organisations maintain storage on a SAN, cheap disks are not an option and it directly adds a performance strain on the SAN infrastructure. It looks MS is shifting the strain elsewhere rather than optimising it. HA features are a welcome move though!

AstroCreep
AstroCreep

For me, the removal of SIS is a BIG deal. Yes, storage is cheap and I have a good 5TB of available space on my SAN, but that needs to last for more than just my Exchange databases. Plus we're running a 95% virtual server environment, so it's not like I can just throw in a couple of extra SATA drives and call it a day. And being that I'll need to create a good three new VMs due to the separate Exchange roles (running Exc2003 right now), that will eat into my available SAN space as well. Maybe not much more than it is now for the servers themselves, but between the servers, the additional space for the databases, and snapshots, that's going to be about 1TB, I'd think. The compression is a nice feature (I remember you and I talking about that in a discussion a few months ago, Scott) but no compression on attachments? That makes me a sad admin, especially when people like to forward e-mails with 5MB worth of pics to 100+ people. Plus my users are digital pack-rats; that 5MB e-mail would probably stick around for years in a good 25% of those mailboxes. ...and yes, we're working on an e-mail retention policy now. :p That will definitely help with the space. But I will miss my SIS!

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