Administrators are caught between a rock and a hard place when it comes to backing up and restoring Microsoft Exchange mailboxes and messages. In traditional backup Exchange environments, if you want back up with any degree of speed, you need to do a "store-level" backup--Exchange parlance for a block-level backup. But it's exceedingly time-consuming to restore individual mailboxes and messages from a store-level backup.
In the past couple of years, Microsoft has introduced the concept of "brick-level backup," which promises to provide more efficient mailbox and message restores. But the downside is that the backup itself takes longer.
Shawn O'Brien, network analyst at Wilson Medical Center, a hospital in Wilson, NC, knows this problem all too well. Using Veritas' (now Symantec's) Backup Exec, an Exchange mailbox restore would take five hours, "and that's only if everything went well," he says.
According to T.M. Ravi, president and CEO at Mimosa Systems, a typical Exchange message restore goes something like this: "Go look for the tape, find the last full, put it on the recovery server, apply the incrementals and pluck out the messages." Wilson Medical experimented with brick-level backup, but O'Brien found that it took more than eight hours to back up approximately 500 mailboxes vs. two hours for a store-level backup.
For that reason, brick-level backup really hasn't taken off, says Missy Koslosky, product manager for Exchange solutions at Quest Software. "Ninety-plus percent of Exchange backups are store-level backups," she says.
Quest recently announced Version 3.0 of Recovery Manager for Exchange, a member of its Exchange Storage Management suite. Building on Quest's mailbox migration tools, the software allows you to restore Exchange from a store-level backup directly to the Quest server, which interprets the data stream according to your search criteria. "We can restore data orders of magnitude faster than doing a regular restore," Koslosky says.
That's important because restore requests are becoming more frequent. "When we first introduced the product, we thought it would be a VP service, but that's not what we've found," Koslosky says. "It's not the users who are asking for things to be restored--it's the auditors and lawyers," doing e-discovery or audits of peoples' e-mail.
At Wilson Medical, the IT staff still gets four or five mailbox restore requests per month. The hospital now runs LiveServ for Exchange by Storactive, a continuous data protection (CDP) application that runs on its own server and stores between seven to 10 days of backups. A message can be restored in less than 10 minutes, says O'Brien, "depending on the user's perception of time," i.e., when the user believes they deleted the message.
Other than the time savings, LiveServ has also allowed Wilson Medical to get rid of its dummy Exchange server. "[It's] been trashed and is long gone," reports O'Brien.
Mimosa Systems also offers CDP-like levels of Exchange protection and restore, but doesn't require a host-side agent. The firm's NearPoint appliance takes an initial full store-level backup via regular Microsoft Exchange backup APIs. It then gathers Exchange transaction logs and applies them to the backup. As Exchange transaction logs are written every 5MB, a given server is never out more than approximately 100 messages, depending on attachments. "In the grand scheme of things, that's pretty awesome," the firm's Ravi says.
To restore a lost e-mail message, users can simply browse the NearPoint appliance, which appears as a new folder in their Outlook window. Thanks to single-instancing of messages and objects, NearPoint is routinely used to store six to nine months of messages--enough to cover the "oops factor," Ravi says. After that point, e-mail retention is typically a function of legal retention policies and can be configured on a site-by-site basis.
Depending on how much disk capacity is available, Ravi says, "this is the equivalent of never having to delete your data again."