From owner-freebsd-questions@freebsd.org Fri Apr 1 04:45:20 2016 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B9A7DAE5E80; Fri, 1 Apr 2016 04:45:20 +0000 (UTC) (envelope-from jdavidlists@gmail.com) Received: from mail-io0-x22e.google.com (mail-io0-x22e.google.com [IPv6:2607:f8b0:4001:c06::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 9057311C5; Fri, 1 Apr 2016 04:45:20 +0000 (UTC) (envelope-from jdavidlists@gmail.com) Received: by mail-io0-x22e.google.com with SMTP id g185so140048178ioa.2; Thu, 31 Mar 2016 21:45:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:date:message-id:subject:from:to :content-transfer-encoding; bh=R2jE2RZ3Pi3IujN0GvHfVVdsNMGr29VRqCAw9KaoBIQ=; b=wM+9rR8z7DYdVfSYnEKggRbFMM3nvm7onqHXnG484l5tEeiFsaRwdfQA5NdZKw8wjw PIDIpy+tSYMUejevK36gutqw3Hj7mjO9qmlTlxqTHdQ8G/Ust8LB6WgI015hJaJdcjJM Jmi/E63nWIICAL3jUr0KthEVTOff5sMbry5aialExTbfmm5nAa8oQUZC6Su9DxUPhZJz akibAWVYxMbrmY2EVxNHK6xhHNXH037dnSxO9kD9yM4iRnU+7wRVRcMiBn2cbNrDYYiS pcStgvYob99QWCAxLH4wp6NdboBZwQEg4uVvk5B9iQ7YO0IK40D2Mip6SG+Dh9eIiOXl wxJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:date:message-id:subject:from :to:content-transfer-encoding; bh=R2jE2RZ3Pi3IujN0GvHfVVdsNMGr29VRqCAw9KaoBIQ=; b=AAgcEyAVb/BtEixgXidl46lxAw8MZsm4NcuJSLNFpa3x4rhnJS9Hmo2D6HInGnYbUn fcMGGiF6mNPQcpIuj0OmDAi92QCmwG4gYDw7uEJ5AnqHcR8s9n6ffgcXRy5kKwzEZogB HXYq6UZ1NZQmUR2P2SdVEnzouxF7J0z5KMkqrwuX7kxxXQG8jMiqWSjlhUGXcLLgwGps l/u3UYGLlYIh0TWmMwSe9xp11PG7rRi8AzMEaNzeLew3Meq8xVa7UZj2brSPkrwe8sNF 1RRUzGQzmsvvqG+i78Kb2Muvz7VZ+g91Aj8bCfMWogfONByE0hJY6WSH2JCYogbWmXpt DsJg== X-Gm-Message-State: AD7BkJKZsnYuzdvUHSrM6WiH8IFExJIwZ1j+crQSoG9Vt4wqcmpOsUdjUsORNBgyRNRryCxcr9XKEGmTGUUJTg== MIME-Version: 1.0 X-Received: by 10.107.41.211 with SMTP id p202mr8644693iop.4.1459485919817; Thu, 31 Mar 2016 21:45:19 -0700 (PDT) Sender: jdavidlists@gmail.com Received: by 10.36.130.130 with HTTP; Thu, 31 Mar 2016 21:45:19 -0700 (PDT) Date: Fri, 1 Apr 2016 00:45:19 -0400 X-Google-Sender-Auth: l69pvbFhzeRFManpfDLdEDmTP2g Message-ID: Subject: Catching core files in read-only jails From: J David To: "freebsd-questions@freebsd.org" , "freebsd-hackers@freebsd.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Apr 2016 04:45:20 -0000 If an application is running on a production server in a read-only jail for security purposes, and it crashes occasionally due to some unknown bug, is there any way to catch a core file? Setting kern.corefile seems to still be relative to the jail. (Or, at least, no corefile is generated.) There are a lot of these processes and they don=E2=80=99t crash very often,= so leaving gdb attached isn=E2=80=99t really feasible either. (It=E2=80=99s b= een tried, but apparently requires a bit more luck than is currently in evidence.) Thusfar all attempts to get it to crash in a controlled/test environment have also been unsuccessful. Does anyone have any ideas for how to find out what=E2=80=99s causing the c= rash? Thanks for any advice!