(no subject)

[Benjamin C.R. LaHaise]

[Please note: I'm not on the Beowulf list, so cc me on any comments]

jakob at unthought.net wrote:

> Two clients can't mount the same FS over nbd though...

You can for read only data (yes, changing the data requires remounting),
and many workloads have a large readonly workset (ie executables and some
data files).

For the case of g98 a per-client disk image provides the space and
performance benefits of a hard drive with the managability and ease of
maintenance networked servers offer.  We know that NFS sucks, and we'd
like to use something better.  This isn't perfect, but it's better than
NFS.

> The clients will all have meta-data caches, and they will be
> inconsistent even though the block data device is the same on the
> server.

That's the entire point of using nbd: unneeded network traffic is avoided,
and the server is simpler and faster.

		-ben