[Linux-cluster] GFS

[David Teigland]

On Tue, Oct 26, 2004 at 04:41:29PM -0400, Dascalu Dragos wrote:
> We are working on a similar scenario but adding mailman into the mix. 
> The ideal outcome would be for multiple mailman/postfix servers to 
> write archives, etc to the same centralized location on a SAN. After 
> doing some tests this setup does not appear to be trivial. We ran into 
> a similar problem when using NFS; if multiple machines write to the 
> same file at the same time the file gets mangled as the machines cut 
> each other off. With GFS we noticed that each machine has a 4k buffer 
> window in which it writes its data. If a second process decides to 
> start writing to the same file we noticed alternating writes to the 
> file after 4k of data.

Note that this sounds like perfectly correct behavior on the part of gfs.
The application is responsible for the necessary file locking, of course,
while gfs is responsible for keeping the fs uncorrupted.

-- 
Dave Teigland  <teigland at redhat.com>