From owner-freebsd-net@freebsd.org Thu Mar 18 12:54:59 2021 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 9D7595743D0 for ; Thu, 18 Mar 2021 12:54:59 +0000 (UTC) (envelope-from michael.tuexen@lurchi.franken.de) Received: from drew.franken.de (drew.ipv6.franken.de [IPv6:2001:638:a02:a001:20e:cff:fe4a:feaa]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.franken.de", Issuer "Sectigo RSA Domain Validation Secure Server CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4F1RnZ66knz3Pxm for ; Thu, 18 Mar 2021 12:54:58 +0000 (UTC) (envelope-from michael.tuexen@lurchi.franken.de) Received: from [IPv6:2a02:8109:1140:c3d:51d6:b5cf:58db:3d5e] (unknown [IPv6:2a02:8109:1140:c3d:51d6:b5cf:58db:3d5e]) (Authenticated sender: lurchi) by mail-n.franken.de (Postfix) with ESMTPSA id 46EC977A91A8A; Thu, 18 Mar 2021 13:54:54 +0100 (CET) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\)) Subject: Re: NFS Mount Hangs From: Michael Tuexen In-Reply-To: Date: Thu, 18 Mar 2021 13:54:53 +0100 Cc: Rick Macklem , Jason Breitman , "freebsd-net@freebsd.org" Content-Transfer-Encoding: quoted-printable Message-Id: <2890D243-AF46-43A4-A1AD-CB0C3481511D@lurchi.franken.de> References: <3750001D-3F1C-4D9A-A9D9-98BCA6CA65A4@tildenparkcapital.com> <33693DE3-7FF8-4FAB-9A75-75576B88A566@tildenparkcapital.com> To: "Scheffenegger, Richard" X-Mailer: Apple Mail (2.3654.60.0.2.21) X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=disabled version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on mail-n.franken.de X-Rspamd-Queue-Id: 4F1RnZ66knz3Pxm X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=none (mx1.freebsd.org: domain of michael.tuexen@lurchi.franken.de has no SPF policy when checking 2001:638:a02:a001:20e:cff:fe4a:feaa) smtp.mailfrom=michael.tuexen@lurchi.franken.de X-Spamd-Result: default: False [-1.60 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; MV_CASE(0.50)[]; MID_RHS_MATCH_FROM(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[franken.de]; ARC_NA(0.00)[]; TO_DN_SOME(0.00)[]; SPAMHAUS_ZRD(0.00)[2001:638:a02:a001:20e:cff:fe4a:feaa:from:127.0.2.255]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[2001:638:a02:a001:20e:cff:fe4a:feaa:from]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-1.00)[-1.000]; AUTH_NA(1.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_SPF_NA(0.00)[no SPF record]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:680, ipnet:2001:638::/32, country:DE]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[freebsd-net] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Mar 2021 12:54:59 -0000 > On 18. Mar 2021, at 13:42, Scheffenegger, Richard = wrote: >=20 >>> Output from the NFS Client when the issue occurs # netstat -an | = grep=20 >>> NFS.Server.IP.X >>> tcp 0 0 NFS.Client.IP.X:46896 NFS.Server.IP.X:2049 = FIN_WAIT2 >> I'm no TCP guy. Hopefully others might know why the client would be = stuck in FIN_WAIT2 (I vaguely recall this means it is waiting for a = fin/ack, but could be wrong?) >=20 > When the client is in Fin-Wait2 this is the state you end up when the = Client side actively close() the tcp session, and then the server also = ACKed the FIN.=20 Jason noted: When the issue occurs, this is what I see on the NFS Server. tcp4 0 0 NFS.Server.IP.X.2049 NFS.Client.IP.X.51550 = CLOSE_WAIT =20 which corresponds to the state on the client side. The server received = the FIN from the client and acked it. The server is waiting for a close call to = happen. So the question is: Is the server also closing the connection? Best regards Michael > This will last for ~2 min or so, but is asynchronous. However, the = same 4-tuple can not be reused during this time. >=20 > With other words, from the socket / TCP, a properly executed active = close() will end up in this state. (If the other side initiated the = close, a passive close, will not end in this state) >=20 >=20 > _______________________________________________ > freebsd-net@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"