> > > > I am using GlusterFS since a few weeks. Surfing the net I stumbled into > this: > > > > http://en.wikipedia.org/wiki/Online_codes > > > > I am wondering if it would be a good idea to make a xlator for GlusterFS > using > > this algorithm. > > > > The advantage of this solution is that you can split a file in N size > blocks, > > and spread them around the bricks. If you lose one brick, you can still > > reconstruct files combining the remaining blocks. It's also quite > efficient. > > > > Kind regards to everybody and compliments for the great job already > done! > > I'm not sure how you would extrapolate this to a client/server > architecture, even one where there may be many servers. > > It seems optimized for a network where everyone participates in the file > sharing (indeed it was developed for P2P usage), maximizing the > possibility that new nodes get data other nodes are less likely to be > sharing. > > I'm not sure how well it would apply to glusterFS, which is > client/server based, as it seems to require P2P type connections. Even > though you CAN run the client and server on the same system in > GlsuterFS, there's a distinction between where data is served from and > where it's mounted to, which isn't usually the case in P2P (indeed, it > can't be the case for this algorithm to work). > > Although, maybe GlusterFS is modular enough that there's some real > interesting translators that can be made to work with this in useful > ways. I can't seem to wrap my head around a useful way though. One use I see (and from what I understand of the paper) is that the algorithm can provide a RAID5/RAID6 like translator where redundancy factor is arbitrary, and this redundancy factor can be increased/decreased on the fly (adding nodes/deleting nodes for redundancy of any N nodes). Also calculation of each block is based upon a pseudorandom number which decides the probability of being able to reconstruct, which makes it necessary to have (1 + e)*n blocks to reconstruct n blocks, where "usually" e is 0. I need to read the paper in greater detail I must admit. avati -- If I traveled to the end of the rainbow As Dame Fortune did intend, Murphy would be there to tell me The pot's at the other end.
