Home RAID and LOCKSS
Great discussion here and on StorageMojo on home RAID Over on StorageMojo the discussion is converging on a low-overhead (in human cycles) solution consisting of local NAS + some kind of automated remote backup. Anybody holding a piece of Mozy or Carbonite should feel good.
Dateline reality: The Voice of Experience StorageMojo got a great comment from a gentleman who identified himself as a designer of a popular RAID-ed NAS appliance for the SOHO market. He also said he runs a user group and an FAQ for the product. Here's what he said:
I was a big proponent of RAID until I found that our customers were placing so much faith in RAID that they were putting all their data on the NAS and then _deleting_ it from ALL other locations. In many cases, they had no off-site storage strategy for their data.
There are multiple ways to lose both drives at once, as we’re finding. For example, in the case of a lightning strike, we had a customer lose both drives, and his mirrored data, even though the PC which was on a surge protector was unscathed. There’s also the case where if you accidentally delete or corrupt a file from one drive, the mirroring function with dutifully delete or corrupt it on the other. RAID cannot protect you from data loss in the event of fire, flood or theft. So I’m now of the opinion that a safer solution is to have an off-site strategy with drives that can be periodically cycled rather than using a RAID-only solution for home users.
It’s not that I don’t like RAID. I do use it myself. It’s just that sometimes we think of a hard drive crash as the only way to lose data and forget about all the other ways the data can be lost.
Whoa, Nelly! It never occurred to me that customers might consider RAID so safe that they'd delete all other copies. It boggles my mind.
Yet it fits with what I see here in small town America: people relying on computers who don't understand them. They're willing to follow directions to get what they want - they just need to know what to do.
The only data protection strategy that works IMHO, there is only one data preservation strategy - not tactic - that works: Lots Of Copies Keeps Stuff Safe (LOCKSS) which is, IIRC, the trademarked name of a non-profit group out of Stanford that supports libraries.
Lots of copies for consumers is probably three, maybe four. At least one remote copy.
What do you copy? The My Documents (Windows) or Documents (Mac) folder, at a minimum. Weekly drag and drop or a backup program, your choice. Perhaps to different media such as magnetic, optical or flash.
There is more than one way to copy On my POP accounts, I've set Mail to delete the server copy 30 days after download. So I have two copies of every email for the past month without lifting a finger. Why isn't that the default for mail clients?
I also keep the CDs I've ripped into iTunes, so those are backed up as well. Multiple copies needn't mean more work or disk capacity.
Many voices, one message: lots of copies I propose that the storage industry get an independent consortium together to promote the importance of data copies to consumers. If we can just get that across to users - not worrying about RAID, local or remote, NAS or SAN, optical or magnetic - we will perform a valuable public service.
Consumers who care can focus on ensuring they have multiple copies of their data. Everyone who provides products or services that preserve data, from ISPs to NAS boxes to USB disks, could include the Keep Stuff Safe message.
The Storage Bits take Sure, the industry would probably sell more storage. That's not the point. We'd be helping people who don't understand the technology do the right thing. Once they get the message they can think about what works best for them given their needs and resources.
Digital literacy includes the care and preservation of digital data. Educating consumers now will save many much expense and pain later.
Comments welcome, of course. I'm very pleased with the quality of the attention this issue has received.