How Thin Are You?
Posted on Jul 30, 2007 by Stephen
So thin provisioning is everywhere! Well, at least that’s what you would think if you’ve read all the press releases this year. It seems like everyone has just announced and provisioning. So how can you tell them apart? Here are a few easy questions to ask!
- Is it generally available? Many vendors have announced thin provisioning as a future feature in their next generation software or hardware. But not all of them are shipping it today, and some don’t plan on ever delivering it for the box you have on the floor.
- How thin is thin? Many thin provisioning implementations use a fixed page size, forcing you to add more space than you want. Others are so granular, it makes me wonder how they manage the overhead.
- Can my relatives get thin, too? Although some arrays can now virtualize other storage behind them, not all can apply thin provisioning to these “cousins”.
- How about my brothers and sisters? Again, not all storage volumes are created equally. Some arrays can’t apply thin provisioning to snapshot or replication sources or targets.
- If I get fat, can I go on a diet? Once space has been provisioned to a thin volume, you may not be able to reclaim it if it is no longer needed. Find out if your allocations can be reversed. Note: This is harder than it sounds to engineer!
- How automated are my allocations? Find out how much overhead and effort you will have to put into managing your thin volumes. Operator time might be more costly than disk space in the long run.
Do any of the storage vendors in the audience want to comment on this?
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http://blog.fosketts.net/2008/10/16/symantecs-thin-api-step-direction/ Symantec’s Thin API Is A Step In The Right Direction – Stephen Foskett, Pack Rat