On on. 24. okt. 2012 kl. 08.42 +0200, Brian Candler wrote: > I don't think it was even accurate. What it probably meant was that NFS > failover requires inode numbers to be consistent between the two > filesystems, because inode numbers are used as part of the NFS file handle. > Block-by-block replication is one way to achieve that. But it turns out this requirement comes with the use of NFS4, if I'm right? NFS3 is stateless, but NFS4 is not. >>>> Can I somehow enable block-for-block replication with GlusterFS? >>> >>> No. You are reading documentation for something completely different: a pair >>> of machines synchronised at the block level using DRBD, in a master/slave >>> configuration (that is: all writes must be made on the master side, and the >>> block changes are replicated a la RAID1 but over a network). >> >> Hm. I don't see how your reply indicates the lack of block-by-block >> replication in GlusterFS. > > GlusterFS replication works at a different layer: each glusterfs brick sits > on top of a local filesystem, and the operations are at the level of files > (roughly "open file named X", "seek", "read file", "write file") rather than > block-level operations. Hm, does this mean the whole file will be replicated each time it changes? If so, it would seem unfit to store VM images. -- Best Regards Runar Ingebrigtsen
