The traditional "nights and weekends" backup window keeps getting smaller and smaller. Particularly for enterprises...
doing business in a 24/7 global context, it practically doesn't exist at all. As enterprises confront this problem, a number of promising options are developing.
W. Curtis Preston says the two main choices, are LAN-free backup and the more ambitious "incremental forever." The former, defined by SNIA as "a disk backup methodology in which a SAN appliance performs the actual backup I/O operations, thus freeing the LAN server to perform I/O operations on behalf of LAN clients," is good but not good enough for some people, says Preston. He points out that although the method is faster, it still presumes some kind of backup window.
Incremental forever, which has a wide range of variants and employs different methodologies, drops the requirement for a traditional backup window entirely and makes sure that data is preserved frequently or even continuously. Preston says there is a range of old and new technologies being used for incremental such as Tivoli Storage Manager (TSM), an enterprise class product, and Veritas Netbackup.
However, warns Preston, current products deal with file-level backup and thus aren't a good solution for backup of databases.
Then there's the question of what is being replicated and backed up. "If you are constantly replicating and you have a logical correction -- say, if someone accidentally deleted a table -- you need to be able to capture prior versions of the data," says Preston. Otherwise, the replication system will go on, simply replicating data that is now inaccurate.
Preston says that some products are starting to offer "snapshot" capabilities or a logging system that records changes to files. Ultimately, Preston envisions most organizations going to systems where there is always a second, state-aware copy of data available, completely eliminating both backup and restore as it is currently practiced. "That will be happening over the next three or four years," he says.
For now, Mike Karp of Enterprise Management Associates, believes many enterprises are staring at a Hobson's Choice: they must either risk losing data, by sometimes forgoing backups, or risk losing business, by taking production systems down to provide backup windows.
Like Preston, Karp sees the answer in ever more automated solutions, particularly those that can capture both data and state. However, he warns, some organizations are trying to build such systems on the cheap, with too little horsepower on the replication side of the house. "If you are running on a $500,000 system and backing up on to a $50,000 system, you are risking trouble," he says.
And for those not yet ready to embrace the potential costs of such high-level solutions, Karp recommends investments in the "better" traditional backup technologies. One of his favorites, he says, is Falconstor's, which he calls "dandy technology." That's yet another solution that tries to put traditional backup on steroids. In the case of Falconstor that means providing a disk-based system that looks just like tape as far as the infrastructure is concerned, but runs a lot faster. And, at the end of the day, it still lets you write to tape for a higher level of security, but without tying up a long backup window.
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About the author: Alan Earls is a freelance writer in Franklin, MA.