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|Reducing storage demand in a customer's e-mail system|
Recognizing the importance of better e-mail management, vendors have been pushing out products specifically targeted at this area. Veritas, Mountain View, CA, offers hierarchical storage management (HSM)-like e-mail archiving through its NetBackup Storage Migrator (NSM) application. NSM, which only works with Exchange, lets storage administrators create policies that manage the retention of e-mails. Messages past a certain age, having certain keywords, containing attachments of a certain size or meeting other criteria are automatically moved off the Exchange server onto nearline or offline storage. On the client end, archived messages are indicated with a special icon, letting users retrieving know with a notification that it's being pulled out of the archive.
Veritas' NSM doesn't yet offer features for eliminating space consumed by redundant attachments, but still offers space savings that storage administrators should definitely look for it when choosing an e-mail management platform.
Legato Systems, also of Mountain View, CA, spent $403 million to buy OTG Software, Rockville, MD, whose DiskXtender, ApplicationXtender, and EmailXtender products help improve the archiving and management of data between storage media.
DiskXtender monitors usage of files and moves less-used files to nearline or offline storage. ApplicationXtender takes a similar approach for enterprise content, although this method doesn't work for e-mail, since multimegabyte e-mail files are constantly changing. This makes DiskXtender think they're frequently used and therefore leaves them alone.
EmailXtender, however, works at the individual e-mail level to intercept, archive, index and retrieve the messages one by one. More importantly, its Single Instance Storage (SIS) algorithm breaks e-mails into their individual elements, spotting cases where more than one message incorporates the same attachment. One instance of the attachment is stored in the system's database, and the e-mail's reference to that attachment is changed into a pointer that directs users to that single copy.
"The bulk of the storage impact is in e-mail messages and attachments," says Amena Ali, senior vice president of marketing for Legato's Management Solutions Group. "Our customers confirm the 80/20 rule: Generally speaking, 80% of data can be archived because most people don't use it. So we offer the ability to do more effective storage management, with storage driven by policies that are relevant to your applications. Think of it as HSM on steroids."
The effect can be dramatic. When Bob in marketing forwards his 400KB Excel spreadsheet to 15 of his co-workers, those 16 copies of the data would normally consume 6MB of disk space. Using SIS, the same messages are archived with just the one instance of the spreadsheet and pointers to it in the 15 copies. Users don't notice the difference, and total disk consumption is just 400KB. Extrapolate these savings to a real network with thousands of users, and it's clear just how much easier such systems can help ease the e-mail flood.
This was first published in October 2002