Patch to add support for advertising FULLSYNC to Mac OSX Clients

Jeremy Allison jra at samba.org
Fri Apr 7 22:39:35 UTC 2017


On Fri, Apr 07, 2017 at 05:27:02PM -0400, Kevin Anderson wrote:
> 
> From what I can tell through tracing fsync's on the server and traffic
> from the client, the client writes data to a band asynchronously and
> the final write to a band triggers the fsync (or after a set amount of
> data is added to the band) at which point the client waits on a reply
> from the server before attempting to move on to the next band in the
> image or perform another operation.

But that is assuming that the client is doing nothing else to
that server. There's NO reason at all the client can't be
submitting other requests to a share number #2 on the same
server at the same time it's waiting for the fsync reply
on share number #1 - or even be writing to a different
file on share number #1.

There is *absolutely* no reason for the client to be
blocking here. The only process that needs to block
is the time machine backup process that is running
above the client redirector code. And that process
doesn't care if the client is handling other requests
or not.

Sheesh, why is this so hard to get through to people.

Blocking is not a magic bullet. It doesn't get you
anything waiting for an async response doesn't also
get you.



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