From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.sysutils.supervision.general/2657 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Brett Neumeier Newsgroups: gmane.comp.sysutils.supervision.general Subject: Re: s6-linux-init: Actions after unmounting filesystems Date: Sun, 18 Aug 2019 16:36:31 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="0000000000000346ad05906b0536" Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="243805"; mail-complaints-to="usenet@blaine.gmane.org" Cc: Supervision To: Guillermo Original-X-From: supervision-return-2247-gcsg-supervision=m.gmane.org@list.skarnet.org Sun Aug 18 23:36:47 2019 Return-path: Envelope-to: gcsg-supervision@m.gmane.org Original-Received: from alyss.skarnet.org ([95.142.172.232]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1hzSr0-0011HM-DY for gcsg-supervision@m.gmane.org; Sun, 18 Aug 2019 23:36:46 +0200 Original-Received: (qmail 8823 invoked by uid 89); 18 Aug 2019 21:37:11 -0000 Mailing-List: contact supervision-help@list.skarnet.org; run by ezmlm Original-Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Original-Received: (qmail 8816 invoked from network); 18 Aug 2019 21:37:11 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bSAN2J/SfFVkLM6tcTNcQyw/AUYHwMBm8kGIbHGViXc=; b=ARPg+C9E0oTI5pKDI9Hx2OnguweFF33/GQ+IZM9QUm3NkA8P0hVbMERVJfF45vJAmM Lvwv4pTnhWOFRtu5hBvO+qgq4PmFnT9hOLsds7RZKiPM/+wN1dgoPEABcgjIm7inIJ0a 297ugfYLLSTJWel9Z8k/VNPqpGlx3MzPIp02SVi0Yj7qGhJn5dWEzIinMFeCr6+lhlNS mxoVt7UYba9KJe9ATY/cCg9IBWeAUMi31r4Y2DuecyZNcajcaBszG5QPFGy8b0iF2FCZ wZxDgfFQ2/hVCMKeooMs/7TekGXbQvXWPunYh+MOgcno7Q9tL0SjzS+n4Tqk2x5liyMB kmQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bSAN2J/SfFVkLM6tcTNcQyw/AUYHwMBm8kGIbHGViXc=; b=Jf2HnTKAwtKr3bJkJE0wFAekXHXLWWF/xFwhP/UQYFi+Xp5UqhCtRjrhe9uxT6AtJR qXAgXONnAqa6SWBYgkbN4Ief3YY9/DSiuqDysHkSyV+i/pgzAXCop8NZJpH4Ry7JWy+Y NV1uQL25q3Yfx8bnQ20IPbga9zNa21wUD4ToU1GsWOG+jjMj7RxXiZwpHs28+MQ3+K0d U3qrLNIAdMtKSTAhZukmtazFaFPScCXPDTpHajrq7d0Oc+SdY5KkOb+c+1U+sDKg1/X5 tMor/k1BEW1+zJDo+gTsOeZEl62UUBeKiMORaM3gZHawEq92GjUvxYZAUgJUeLPbPNoB Fc6g== X-Gm-Message-State: APjAAAUGE9YsObJMKNJhbAXLJZDWAI5TPVVV8XZ5ZoW6Soig65QvCBpR fzreXiC6+Un3bkufPwRSsGjkAIqx5BqPCw725NU= X-Google-Smtp-Source: APXvYqwKKCsUFawTC1RMj7oCQO6ytsVfHvEiOxY/wr22U+zORMQByq8Vi2DMEWwO2KR+rTJ9EJOG0IfNGsk2akdbZIg= X-Received: by 2002:ac8:5514:: with SMTP id j20mr18354995qtq.230.1566164203552; Sun, 18 Aug 2019 14:36:43 -0700 (PDT) In-Reply-To: Xref: news.gmane.org gmane.comp.sysutils.supervision.general:2657 Archived-At: --0000000000000346ad05906b0536 Content-Type: text/plain; charset="UTF-8" On Sat, Aug 17, 2019 at 2:20 PM Guillermo wrote: > There are certain setups that require doing something after > filesystems are unmounted. Two examples are LVM logical volumes and > LUKS encrypted volumes, but I suppose there must be more cases. In any > such setup, the shutdown sequence would include a 'vgchange -a n' > command or 'cryptsetup close' command after filesystems are unmounted. > How important are these cases? I have not inspected the code to see what cryptsetup close does, aside from remove the encrypted device mapping for the encrypted volume; nor have I looked at the LVM code to see if it does anything other than remove device mapping. But in either case, what I generally do on my systems is simply unmount volumes (or in the case of the root filesystem, remount it read-only), sync to make sure all dirty buffers are written, and then just shut down/reboot/whatever. Leaving LVM and encrypted volumes active has never caused any problems for me. It seems worthwhile to ask whether those examples are real problems that need to be addressed, since all of the proposed solutions have some level of hairiness about them. And if those examples are *not* real issues, it might be worthwhile to ask if there are other examples that *are*. -- Brett Neumeier (bneumeier@gmail.com) --0000000000000346ad05906b0536--