[OpenAFS] Busy call channel when communicating with server ...

Jeffrey Altman jaltman@your-file-system.com
Tue, 04 Sep 2012 09:52:23 -0400

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An rx peer such as an AFS file service will return a RX_PACKET_TYPE_BUSY
response to an RPC if the RPC was issued on a call channel which the
file server believes is still in use.  The most frequent cause of this
condition is when the client's idle dead timeout processing triggers
because the file service accepted an RPC request and has replied with
nothing but keep alive messages for the configured period of time.  It
specific time depends on whether the volume the request was sent to is
replicated or not.  In all cases, the idle dead timeout period will be
longer than 60 seconds.

As the event log message indicates, the client will automatically retry
the request when this situation occurs.  However, the 1.6.1 client on
Windows relies upon the SMB redirector and the SMB protocol has an RPC
request timeout period of a bit more than 45 seconds.  If the SMB
timeout period is reached without a response from the SMB server, (aka
the AFS cache manager \\AFS), then the SMB client will terminate the
connection and it too will begin its own process of attempting retries
and finally reporting errors to the application.

If client side idle dead timeouts are being triggered, it means that the
file service is not responding to clients in a timely fashion and an
effort should be expended to determine why.

The OpenAFS 1.7.17 client does not rely on the SMB redirector.  It
should be used on all Windows platforms as the AFS redirector does not
impose an arbitrary 45 timeout period on file operations.

Jeffrey Altman

On 9/4/2012 2:45 AM, Michael Richter wrote:
> Hi,
> since a month we have infrequent problem on our workstations. The PCs
> are getting unresponsive, programs are crashing, it's not usable. While=

> this happens OpenAFS posts messages like this in 5s-interval:
> Type:    Warning
> Source:    AFS Client
> Event-ID:    4145
> Eventtime:    03.09.2012 16:06:24
> User:    n/z
> Computer:    UBWSTMAPC185
> Description:
> Busy call channel when communicating with server,
> retrying ...
> This does not happen on all PCs. But all PCs use the same software:
> Windows XP Prof SP3, OpenAFS 1.6.1
> I asked our AFS server administrators but it seems that they don't know=

> what's wrong.
> Does someone know what I can do to fix it?
> Michael
> _______________________________________________
> OpenAFS-info mailing list
> OpenAFS-info@openafs.org
> https://lists.openafs.org/mailman/listinfo/openafs-info

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