Microsoft Exchange has become a mission-critical application in today's enterprise. Today's new requirements for Microsoft Exchange involve improving the data backup process, as well as the data recovery and data retention capabilities of Microsoft Exchange. For these requirements to be effective now, a higher level of integration is a must. Knowledge Center contributor George Crump explains how you can better manage Microsoft Exchange's data backup process and its data recovery and data retention capabilities.
E-mail
systems in general, and Microsoft Exchange in particular, have moved
well beyond being an important application in today's enterprise.
Messaging is now a mission-critical application for most
enterprises--as important as a dial tone when it comes to
communication. As a result, Microsoft Exchange is storing much more
than the text of messages; it stores files and multiple versions of files, as well as calendar and contact
information. In many cases, the last known good copy is stored within
the Microsoft Exchange environment.
Today's data protection and management tools for Exchange have not
kept pace. As a result, there are many point solutions
with separate data stores and management interfaces
entering the market to help fill the gap left by the traditional
solutions. The challenge is, while many of these solutions
add value and make life easier for the Exchange or backup
administrator, they add further complexity to the already-complex
problem of data protection. This is because they add separate
subprocesses that require special care and feeding to make sure that
they are working. These stand-alone utilities must then be
integrated back into the backup application, which is again another
step to be monitored for failure.
The new requirements for Exchange involve not only
improving the backup process but also improving the recovery and
retention capabilities of the Exchange environment. For
these requirements to be truly effective, there
must be a much higher level of integration than in the past, so as to
minimize the current workload of the administrator.
Data Protection
Most e-mail systems in a large
corporation receive thousands, if not hundreds of thousands,
of e-mails throughout the day, every day. Yet most Exchange data
protection efforts are a once-per-day occurrence. This simply is
not granular enough; there must be multiple protection instances
throughout the day.
There are SAN-based snapshots that have Exchange integration
to quiesce the Exchange store to get a clean snapshot, but
even those are not often performed in a granular enough
timeframe. Most often, they are performed a few times per
day. Also, SAN-based snapshots are dependent on the primary
system being up and running. While they can protect from a data
corruption issue, they cannot protect from a storage system failure.
New solutions from companies such as
InMage or
Syncsort
that can provide continuous or near-continuous (once-per-hour)
protection of the Exchange environment are answering the call for
improved Exchange availability. This provides block-level backups of
the Exchange environment so that the impact on the server is minimal
and the amount of data transferred across the network to the backup
destination is small. These block-level backups are sent across the
network to a separate storage device so that they are immune
to a failure in the primary storage array. Syncsort has the
added benefit of this process being integrated into the rest
of the process. Typically, an Exchange image can be updated within 5
minutes of the backup job being completed.
Once this data arrives at the backup target, it is then snapshotted,
providing versioning. Since only the block needs to reflect the changes
between each backup, weeks' or even months' worth of Exchange backups
can be stored on disk. Integrating to tape or to some other secondary
storage device is critical when dealing with Exchange data. Long-term
retention of e-mail is going to be increasingly important. Having the
ability to move these backups to a less expensive, long-term storage
medium is critical.
Data Recovery
The requirements for recovery of Exchange are similar to
backup: speed and granularity. A storage system failure or a corruption
of the data set is when speed to recover is most important. And, no
matter the size of your Exchange environment, this can be a
time-consuming process. Despite all the data reduction technologies
available today, in a recovery, all the data has to be sent back across
the network. The network is a bottleneck. All this data has to be
written to disk, and RAID parity has to be recalculated. Disk writes
are a bottleneck.
The best solution is not to have to move data at all. Ideally, you
would want to mount it directly off of the backup target. Because a
block-level, incremental backup system stores data on the disk backup
target in its native format, it can also provide the ability to mount
that data directly. These systems can create a read/write snapshot of
the backup image and serve that up via iSCSI to the Exchange Server.
The Exchange Server can be brought back online and can connect to this
active data set in mere minutes, while the older data is restored back
across the network.
The second, more common recovery request made is to have an
individual contact, mail message, attachment or calendar entry restored
to the Exchange store. In the past, this required special
time-consuming backups, often called brick-level backups. These did not
end up being widely deployed because of the speed at which these
special backups could be performed, and due to the speed at which they
could fulfill a recovery request. Often, after some initial testing,
the module was never used or only used for a few mailboxes. Since most
customers did not use brick-level backups, the real-world solution was
a painful process of recovering to a standby Exchange Server
and then manually pulling out the mailboxes required by the user.
The Active Target capability of block-level incremental backups
provides the ability to have a view of the backup images in real time,
outside of the Exchange environment. This allows for a stand-alone
utility to search the different backup versions of
the environment for a specific message or attachments
and, once found, they can be instantly restored back into the Active
Exchange environment. From the users' perspective, they see
no performance impact; the recovered message
just reappears back in their in-box. This capability can be
used to restore entire mailboxes, individual messages, individual
contacts or calendar entries.
Data Retention and Search
Ninety-five percent of legal discovery requests now involve e-mail.
By combining the capabilities discussed above, an effective discovery
response system can be devised. First, the key component of effective
storage use is there because only changed blocks are stored on the
backup disk. This results in slower disk space consumption, allowing
for longer storage of e-mail backups. If the solution can
provide different retention policies to be set on different data
types, backups of other data can be sent to tape much sooner,
optimizing disk capacity for the longer
retention requirements of the Exchange data.
Second, with an interface into this backup data as if it were a live
Exchange environment, queries can be built based on keywords or users
and date ranges. This data can then be exported out of the environment
as a PST file to be sent to the opposing legal counsel for
review. The whole process would take minutes as opposed to the hours
involved in standing up a second Exchange Server, doing the restores to
it and then trying to search for the data. This solution provides much
of the retention and search requirements that e-mail archive
solutions can offer, without the expense of purchasing a stand-alone
system.
Today, Microsoft Exchange has become a mission-critical operation.
When something goes wrong, it must be recovered as quickly as possible
with as minimal data loss as possible. These new solutions deliver
these capabilities, plus the added benefit of meeting most legal
retention and search requirements.
George Crump is the founder of Storage Switzerland,
an analyst firm focused on the virtualization and storage
marketplaces. An industry veteran of over 25 years, he has
held engineering and sales positions at various IT industry
manufacturers and integrators. Prior to founding Storage
Switzerland, George was CTO at one of the nation's largest
integrators. He can be reached at georgeacrump@mac.com.
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