Exchange 2010 Archiving: Summary & Assessment
Exchange 2010, announced on April 15, 2009, has built-in email archiving. In summary:
- Tightly integrated with Outlook.
- PSTs can be dragged and dropped into the archive.
- Unified search across the live message store and the archive.
- Search across multiple mailboxes for qualified staff.
- Simple retention policies, based on the number of days of retention, can be defined. These policies can be defined to apply to a folder, individual messages, or an entire mailbox.
- Legal holds can be imposed, overriding defined retention policy.
- There's basic mailbox and configuration logs and auditing.
- Stubbing's not used.
- It's very good that Exchange now has built-in archiving. This will be welcomed by many people and organizations, because purchasing and supporting a third-party archiving product introduces complexity and requires resources.
- This is a solid and attractive first step for Microsoft in email archiving.
- The capability is a sound basis for future enhancements. Examples of areas which no doubt Microsoft will make up for current shortcomings include:
- More powerful policy definition and enforcement for determining what gets archived, retention policies, and content tagging/labels. Today these facilties are rudimentary.
- Integrated support for instant messaging, SharePoint, and Windows files and folders. Today only email, voice messages, and text messages are supported.
- Integrated support for other archive repositories, such as Documentum.
- You often end up going to PowerShell to implement controls. As these settle down, Microsoft will implement corresponding GUIs.
- For the moment, third-party products will continue to be able to compete based on superior capabilities. Longer term, however, it's likely that the market for third-party email archiving technology for Exchange will gradually diminish.
- We look forward to learning more about the archiving. There are plenty of open questions, such as:
- How scalable is it?
- How will it integrate with other archives?
- Do PSTs go away?
- How are messages ingested?
- How important is the archiving in reducing the size of large mail stores, given that stubbing isn't used?
... David Ferris
Exchange 2010: Exciting Message Store Performance and Redundancy Improvements
Maintaining the integrity of, and timely access to, a user's message store has been a major dilemma for Exchange over the years. Exchange lagged badly behind Lotus Notes/Domino because:
- Lotus Notes employed a single OS file to hold a single user's mail file, while Exchange used a single "storage group" to hold multiple users' messages. This had the effect that a disk error affected many more users, and a restore from backup took much longer.
- Exchange was much more disk I/O intensive, which meant that the likelihood of a disk error was increased.
- Lotus Notes offered "shared nothing" multisite clustering, while Exchange only offered backup and restore.
This was largely a legacy of the environment for which Exchange was designed. The power of servers and the size of disks in the late 1980s meant that Exchange, like Notes in the early 1980s, was originally designed to support relatively small numbers of users per server, each with a relatively small message store. The effect of Moore's Law on both CPU power and RAM size, along with a 120% compound growth rate in disk bit density/cost, has meant that hardware is no longer a limiting factor. A single server is conceptually able to support many thousands of users, and disks many gigabytes of messages.
Unfortunately until its 2007 release, Exchange was largely hamstrung in its support of bigger servers and larger and cheaper disks. The problem was that Exchange was disk I/O limited. With the leap to "64-bit only" support in Exchange 2007, which resulted in a 60-70% reduction in disk I/O, and now with an additional 70% reduction in disk I/O under Exchange 2010, Exchange has finally broken free of its disk I/O straitjacket. In addition to increasing the number of users that can be supported per server, this reduction in disk I/O has the following knock on effects:
- Exchange 2010 is able to employ much cheaper EDI (SATA) as opposed to SCSI and Fiber Channel disks. EDI disks trade-off an order of magnitude (1TB, SATA II @ $105 vs. 300GB, ULTRA SCSI @ $350) improvement in per-bit cost against poorer performance (7.2k RPM SATA II vs. 15k RPM, ULTRA SCSI) and reliability.
- Exchange 2010 is able to support "shared nothing" replication, via "log replay," of mailbox databases both within and between data centers for load balancing and much more rapid post-disaster availability.
Collectively these changes deliver the following benefits:
- They allow a backup/restore approach to disaster recovery to be replaced by a multicopy/multisite/online approach to disaster recovery.
- Eliminating backup/restore enables much bigger mailboxes/message stores.
- Supporting multicopy/multisite/online redundancy delivers much more rapid "disaster recovery."
- They allow a switch to SATA drives. This delivers:
- A near four-fold increase in mailbox/message store quotas/sizes.
- A near four-fold increase in multisite data redundancy.
- A near four-fold increase in disk density.
- All at no increase in cost!
- The multicopy/online approach to redundancy eliminates the need for RAID(1 or 5)-delivered redundancy. This is good news, because:
- While theoretically, RAID-delivered redundancy should increase reliability, in practice, buggy RAID controller firmware and drivers often detect bogus errors requiring at best operator intervention, and at worst performance-sapping rebuilds, and even reboots!
Ferris is excited about these developments in Exchange 2010. They deliver considerable new benefits to the Exchange value proposition. At the same time, achieving the benefits requires a fairly major change of mindset among Exchange deployment architects. This is especially the case when replacing expensive SAN-based disk drives and SNAP-based backups with directly attached SATA disk drives and multisite replication. ... Nick Shelness
Exchange 2010: Summary & Key Features
On April 15, 2009, Microsoft released a public beta of the next version of Exchange, Microsoft Exchange Server 2010. This has hitherto been known as Exchange 14, and been tested by some five million users via Microsoft's Outlook Live for Live@Edu program. General availability will be in 2H09.
For this author, the most important aspects of E2010 are:
- Most of Exchange 2007 has been rewritten to better support large-scale deployments. Among other things, it has delegated administration with a much richer set of permissions. Far more work can now be pushed down to users and user-level administrators, with a lot of flexibility.
- There is built-in archiving with retention policy and e-discovery support. Long term, this is likely to mean that the market for independent archiving products goes away. See our accompanying bulletin, Exchange 2010 Archiving: Summary & Assessment.
- There's seamless coexistence between Exchange Online and Exchange 2010 implemented on-premises. This is very elegant, and based on a strong and innovative underlying identity architecture which we've discussed in other bulletins.
- There's a centralized policy definition and management system. This is based on mainstream regular expression pattern matching and simple boolean logic, applying to message content and metadata, and for users and groups of users. Polices can be enforced manually or through user intervention. The policy framework is used in a variety of contexts, such as for data leak prevention, rights management, determining what is archived, and retention policy.
- Quite a lot of features are rudimentary, such as the ability to define tags and control what's archived. However, the basic infrastructure is there, and there's a path for future enhancements to provide greater sophistication. Similarly, plenty of features are now implemented in PowerShell; more friendly GUIs will follow later.
E2010 has many other improvements, many of which will be appreciated by users or administrators. They include:
- The Windows Mobile experience is now very close to that of desktop Outlook.
- With "MailTips," users are automatically warned about potential faux pas when an an email is about to be sent, such as when a distribution list will cause it to be received by a very large number of people, or when the email is so large it's likely to bounce, or when recipients are out of the office.
- OWA now supports all the main browsers including Safari and Firefox, not just IE.
- Email conversations are much easier to manage via the updated Conversation View.
- Voicemail previews: Text previews are generated of voicemail in Outlook, OWA, and Outlook Mobile. This saves a lot of time when quickly scanning through voice messages.
- Free/busy times can be exchanged with outside parties, not just internal colleagues, with due privacy controls.
- User-customizable voicemail menu hierarchies.
- Much reduced I/O and much more flexible storage options. Continuous replication over WANs is now practical, and provides much faster recovery for damaged message stores. There is generally better resilience in case of system failure. See our accompanying bulletin, Exchange 2010: Exciting Message Store Performance and Redundancy Improvements, for a detailed assessment.
- Much faster mailbox moves; can be done while users are online, during regular business hours.
- Microsoft points out that a number of these features help address the problem of mailbox overload, such as MailTips, Voicemail previews, the conversation management tools, the call answering rules, and the rich and consistent Windows/OWA/mobile experience. All of these are welcome and good developments. However, don't expect email overload to go away.
... David Ferris
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