The 2006 Linux Filesystems Workshop (Part II)
Posted Jul 6, 2006 12:29 UTC (Thu) by sveinrn
Parent article: The 2006 Linux Filesystems Workshop (Part II)
Where I work, we are collecting really expensive data that has to be stored on online disks for the eternity. And thinking through how to protect the data from long term corruption has been a really interesting excersice. We ended up with a separate database storing md5 chekcsums of every file and then scanning the files regularly restoring files from backup that do not match the checksum.
But the most interesting suggestion that came up, was creating a raid system based on the Hamming code. So that first we would have a number of data disks. Then a number of disks storing the parity bits of the Hamming code. And on top of that, two parity disks for RAID6. As far as I can see, a scheme like this will protect against most of the error scenarios described in this article. It will of course require a great number of parity disks, and writing data will be extremely slow. Also, a battery backed write cache will be essential. But for archive-systems with only a few daily write operations I think it could work. Does anybody know if a system like this has ever been tried?
to post comments)