How to avoid client timeout.(SMB2 ECHO Request)

[sandeep nag]

As Richard mentioned we support only SMB1.

I see the entry ' async smb echo handler'  with value yes/no in smb.conf is
having* no* effect. That is, When when I capture network packet capture
from windows client
with 'async smb echo handler' set to 'yes' by blocking the smbd process
write request, I am not seeing the reply to client 'Echo Request'  pkt from
samba server.

What is the test, I can perform to confirm that  'async smb echo handler'
is working?

Thanks,
Sandeep



On Fri, Feb 7, 2014 at 8:38 PM, Richard Sharpe
<realrichardsharpe at gmail.com>wrote:

> On Fri, Feb 7, 2014 at 4:57 AM, Stefan (metze) Metzmacher
> <metze at samba.org> wrote:
> > Am 07.02.2014 07:00, schrieb sandeep nag:
> >> http://msdn.microsoft.com/en-us/library/cc246540.aspx
> >>
> >> There is write/truncate request from the client and processing in samba
> VFS
> >> plugin is taking longer time(which is expected as per our VFS plugin
> >> processing time).
> >> The client meanwhile sends many SMB ECHO requests
> >> (every 30 seconds (not sure)). However, they sit in the socket because
> the
> >> smbd
> >> is now stuck and will only process the ECHOs after the truncate. Because
> >> of this, I am seeing client time outs.
> >>
> >> If the ECHO could be responded promptly, then the client would not time.
> >> How can this be done, please guide me in
> implementing/coding/undertanding
> >> this.
> >
> > Which client sends SMB2 Echo requests? Can you provide a capture?
> > I thought Windows clients would rely on TCP keepalives for SMB2.
> >
> > For SMB1 we have the "async smb echo handler" option. From man smb.conf:
> >
> >        async smb echo handler (G)
> >
> >            This parameter specifies whether Samba should fork the async
> > smb echo handler. It can be beneficial if your
> >            file system can block syscalls for a very long time. In some
> > circumstances, it prolongs the timeout that
> >            Windows uses to determine whether a connection is dead.
> >
> >            Default: async smb echo handler = no
>
> He was being sloppy with his terminology. They use Samba 3.5.15 plus a
> bit. Thus, they only support SMB1.
>
> --
> Regards,
> Richard Sharpe
> (何以解憂？唯有杜康。--曹操)
>