On Fri, 16 May 2008, Derek Price wrote:
gordan@xxxxxxxxxx wrote:
This would need a change in the handling of how a file is locked/accessed.
A lock would need to be made on all the nodes that could respond with the
file. AFR doesn't quite do this, the primary node (first one on the AFR
list) is the one that acts as the lock server. If this could be overcome,
then you'd have most of the components you need.
What about a quorum locking solution like DLM provides? I think it doesn't
matter if the server(s) that have copies of the files agree to the file lock,
as long as any server that wants a lock knows to get approval from the
quorum.
Isn't that effectively the same thing? Unless there is quorum, DLM locks
out the entire FS (it also does this when a node dies, until it gets
definitive confirmation that it has been successfully fenced). For normal
file I/O all nodes in the cluster have to acknowledge a lock before it can
be granted.
Gordan
