From nobody Mon Mar 4 02:44:20 2024 X-Original-To: stable@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Tp31h4zLwz5Bc26 for ; Mon, 4 Mar 2024 02:44:24 +0000 (UTC) (envelope-from wollman@hergotha.csail.mit.edu) Received: from hergotha.csail.mit.edu (tunnel82308-pt.tunnel.tserv4.nyc4.ipv6.he.net [IPv6:2001:470:1f06:ccb::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "garrett.wollman.name", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Tp31g5Sc0z4vPY for ; Mon, 4 Mar 2024 02:44:23 +0000 (UTC) (envelope-from wollman@hergotha.csail.mit.edu) Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=bimajority.org (policy=none); spf=pass (mx1.freebsd.org: domain of wollman@hergotha.csail.mit.edu designates 2001:470:1f06:ccb::2 as permitted sender) smtp.mailfrom=wollman@hergotha.csail.mit.edu Received: from hergotha.csail.mit.edu (localhost [127.0.0.1]) by hergotha.csail.mit.edu (8.17.1/8.17.1) with ESMTPS id 4242iLYO074759 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sun, 3 Mar 2024 21:44:21 -0500 (EST) (envelope-from wollman@hergotha.csail.mit.edu) Received: (from wollman@localhost) by hergotha.csail.mit.edu (8.17.1/8.17.1/Submit) id 4242iKmA074758; Sun, 3 Mar 2024 21:44:20 -0500 (EST) (envelope-from wollman) List-Id: Production branch of FreeBSD source code List-Archive: https://lists.freebsd.org/archives/freebsd-stable List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <26085.13700.20875.520319@hergotha.csail.mit.edu> Date: Sun, 3 Mar 2024 21:44:20 -0500 From: Garrett Wollman To: Rick Macklem Cc: Garrett Wollman , stable@freebsd.org Subject: Re: 13-stable NFS server hang In-Reply-To: References: <26078.50375.679881.64018@hergotha.csail.mit.edu> <26083.64612.717082.366639@hergotha.csail.mit.edu> X-Mailer: VM 8.2.0b under 29.1 (amd64-portbld-freebsd13.2) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.4 (hergotha.csail.mit.edu [0.0.0.0]); Sun, 03 Mar 2024 21:44:21 -0500 (EST) X-Spam-Status: No, score=-4.5 required=5.0 tests=ALL_TRUSTED, HEADER_FROM_DIFFERENT_DOMAINS,NICE_REPLY_A,T_SCC_BODY_TEXT_LINE autolearn=disabled version=4.0.0 X-Spam-Checker-Version: SpamAssassin 4.0.0 (2022-12-14) on hergotha.csail.mit.edu X-Spamd-Bar: -- X-Spamd-Result: default: False [-2.90 / 15.00]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_SHORT(-1.00)[-0.999]; FORGED_SENDER(0.30)[wollman@bimajority.org,wollman@hergotha.csail.mit.edu]; R_SPF_ALLOW(-0.20)[+ip6:2001:470:1f06:ccb::2]; DMARC_POLICY_SOFTFAIL(0.10)[bimajority.org : SPF not aligned (relaxed), No valid DKIM,none]; MIME_GOOD(-0.10)[text/plain]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEFALL_USER(0.00)[wollman]; TO_DN_SOME(0.00)[]; TAGGED_RCPT(0.00)[]; FREEMAIL_TO(0.00)[gmail.com]; R_DKIM_NA(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; FROM_NEQ_ENVFROM(0.00)[wollman@bimajority.org,wollman@hergotha.csail.mit.edu]; ARC_NA(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MLMMJ_DEST(0.00)[stable@freebsd.org]; RCVD_TLS_LAST(0.00)[]; RCPT_COUNT_THREE(0.00)[3] X-Rspamd-Queue-Id: 4Tp31g5Sc0z4vPY < said: >> [I wrote:] >> (and so is dirty), this might take several seconds. I've set >> vfs.zfs.dmu_offset_next_sync=0 on the server that was hurting the most >> and am watching to see if we have more freezes. >> >> If this does the trick, then I can delay deploying a new kernel until >> April, after my upcoming vacation. > Interesting. Please let us know how it goes. It's been about 22 hours since I flipped the sysctl and it hasn't happened once yet. Of course I don't know what the users are up to right now, so I'll continue to monitor. This is the script I ended up with to monitor: nfsstat -dW | awk 'BEGIN { n = 0 } (n == 0) && ($12 == 0) { n = n + 1; system("date"); next } (n > 0) && ($12 == 0) { system("date; procstat -k 1184 1198; netstat -n -p tcp"); exit(0) } { n = 0 }' This should (if I haven't botched it) trigger only if two consecutive seconds show no forward progress. -GAWollman