Chris Samuel wrote:
On Mon, 21 Sep 2015 07:54:55 PM Peter Ross wrote:
> I would like to export parts of the server file systems but do not
> need to share them between the clients. So I don't need all the
> overhead of leases that expire, server-side locking etc.
>
> Instead it would be good enough to do locking on the client side and
> write a journal which can be send to the file server.
Isn't this basically NFSv4 delegations? If you're exporting it to just a
single client then I'd expect no other client can interfere with them.
https://www.ietf.org/rfc/rfc3530.txt
1.4.6. Client Caching and Delegation
[...]
The major addition to NFS version 4 in the area of caching is the
ability of the server to delegate certain responsibilities to the
client. When the server grants a delegation for a file to a client,
the client is guaranteed certain semantics with respect to the
sharing of that file with other clients. At OPEN, the server may
provide the client either a read or write delegation for the file.
If the client is granted a read delegation, it is assured that no
other client has the ability to write to the file for the duration of
the delegation. If the client is granted a write delegation, the
client is assured that no other client has read or write access to
the file.
Delegations can be recalled by the server. If another client
requests access to the file in such a way that the access conflicts
with the granted delegation, the server is able to notify the initial
client and recall the delegation. This requires that a callback path
exist between the server and client. If this callback path does not
exist, then delegations can not be granted. The essence of a
delegation is that it allows the client to locally service operations
such as OPEN, CLOSE, LOCK, LOCKU, READ, WRITE without immediate
interaction with the server.
Yes, that sounds like it.
I have to investigate how to configure this behaviour. I could not find it in the nfs(5) manpage of CentOS6 servers.
Yes, Russell, I thought of iSCSI but in this case I want to make use of the server filesystem.
Regards
Peter