smbd blocking in receive_smb

David Collier-Brown davecb at
Tue Aug 6 08:11:02 GMT 2002

Pascal wrote:
> I've read your problem report in the samba-technical list and it seems I am
> experiencing the same symptoms on some servers too.
> I noticed that the 'dead' smbd are in fact blocked because the network socket
> is still to be closed by the client side (connexion showed as CLOSE_WAIT in
> netstat -an).

	Hmmn: I think this is another variant of a known
	Windows <censored> feature.  Try adding
		dead time = 10
		keepalive = 3600
	to the conf file, which should clean up broken
	clients after 10 minutes of apparent death.

	If ten minutes is too long 9and it may well be),
	change just keepalive to 30 (seconds).  This will 
	cause samba to notice if a client goes silent for 30 
	seconds and send them an "are you alive" query.  If 
	they aren't alive samba will tear them down and release
	any  datastructures and locks they're holding.

	This is usually a symptom of a network or client
	problem: I have a note about an earlier symptom at


Horst wrote:
> The visible symptom is that users find themselves locked out of files by
> their own processes.  On the server side we find that users have multiple
> smbd's running that are talking to the same PC.  One smbd will be the
> active one and others (older ones) will be blocked and will not respond to
> SIGTERM.  Killing with other signals works, but leaves old locks in the
> lock database.
> Below I've included a sample of four processes shown in smbstatus output
> and the gdb backtrace of each of the four.  Three of them are blocked in
> read_data and not being responsive to the client PC anymore.  Clearly, as
> each of these processes blocked the client PC happily started a new one.
> The smbd version is 2.2.5 on Linux, Redhat 7.2.
> I realize that everyone is working on more exciting aspects of Samba but
> wonder if anybody more familiar with the util_sock.c routines and
> signalling would have ideas or hints for me to debug further.  The receive
> code gets twisty and I'm not sure I totally understand how it's supposed
> to be working with keepalive packets and such.
> --Eric

David Collier-Brown,           | Always do right. This will gratify 
Performance & Engineering      | some people and astonish the rest.
Americas Customer Engineering, |                      -- Mark Twain
(905) 415-2849                 | davecb at

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