Re: [nfsv4] New version of sparse draft (draft-hildebrand-nfsv4-read-sparse-01.txt)

[Spencer Shepler <[e-mail]>]

Thanks for the update, Dean.

I tend to agree with others that it is likely best to introduce a new READ operation that
incorporates the ideas presented in this draft.  This new operation could allow for a
scatter/gather-like mechanism.  Allowing the client to do a 1MB read and obtain all
of the data within that range while reducing the amount of data transferred is
attractive.

More generally, your draft does combine the idea of space allocated at the server
for the file with the method of effective transfer of data when zeros or unallocated
or uninitialized ranges exist.  It is fine to combine the two ideas in the draft but
a little more explicit language would be helpful (I will make some suggestions offline).

It may be helpful to combine the these READ hole ideas with space allocation
controls provided to the client (allocate, release/trim, etc.).  Anyone else
in the WG have an opinion here?

Spencer

From: [e-mail] [mailto:[e-mail]] On Behalf Of Dean Hildebrand
Sent: Wednesday, September 29, 2010 4:41 PM
To: [e-mail]
Subject: [nfsv4] New version of sparse draft (draft-hildebrand-nfsv4-read-sparse-01.txt)

Hello,

I uploaded a new version of our internet draft "Simple and Efficient Read Support for Sparse Files".

http://www.ietf.org/id/draft-hildebrand-nfsv4-read-sparse-01.txt

Please have a look and give us any feedback.

The main changes are:
1) Added section regarding pNFS (which basically states that there are no real changes to how pNFS works)
2) Added example sparse read message flow
3) Added statement to the effect that if a client sends a read request for a chunk that ends in zeroes, the server can return a short read (thanks to Benny)
4) I didn't change the return value.  There was a suggestion to use a flag instead of overloaded the length parameter, but I'm not sure what this gives us (although it might be more clear in the doc)

Dean