On Fri, 22 Apr 2011 09:05:16 EDT erik quanstrom <quans...@quanstro.net> wrote: > > It all boils down to having to cope with individual units' > > limits and failures. > > > > If a file needs to be larger than the capacity of the largest > > disk, you stripe data across multiple disks. To handle disk > > failures you use mirroring or parity across multiple disks. > > To increase performance beyond what a single controller can > > do, you add multiple disk controllers. > > striping, mirroring, etc really don't need to affect the file system > layout. ken fs, of course, is one example. the mirroring or striping > is one example. in the case of ken fs on aoe, ken fs doesn't even > know at any level that there are raid5s down there. same as with > a regular hba raid controller. > > since inside a disk drive, there is also striping across platters and > wierd remapping games (and then there's flash), and i don't see > any justification for calling this a "different fs layout". you wouldn't > say you changed datastructures if you use 8x1gb dimms instead of > 4x2gb, would you?
I am not getting through.... Check out some papers on http://www.cs.cmu.edu/~garth/ See http://www.pdl.cmu.edu/PDL-FTP/NASD/asplos98.pdf for instance.
