Bug#78834: marked as done (Support for mounting /usr readonly)
Your message dated Mon, 11 Dec 2000 19:58:33 +0100
with message-id <20001211195833.N4346@cistron.nl>
and subject line Bug#78834: Support for mounting /usr readonly
has caused the attached Bug report to be marked as done.
This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.
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Darren Benham
(administrator, Debian Bugs database)
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Received: (at submit) by bugs.debian.org; 5 Dec 2000 14:23:48 +0000
>From Simon.Richter@phobos.fs.tum.de Tue Dec 05 08:23:48 2000
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Date: Tue, 5 Dec 2000 15:23:23 +0100 (CET)
From: Simon Richter <Simon.Richter@phobos.fs.tum.de>
To: submit@bugs.debian.org
Subject: Support for mounting /usr readonly
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Hi,
My usual setup is to have /usr mounted readonly and have apt remount it
r/w when it calls dpkg. This saves me about 20 minutes of fsck time, as
/usr has many small files on it.
However, this approach only works as long as no postinst script starts a
daemon on /usr. After that, the filesystem is marked busy and cannot be
properly remounted read-only.
As postinst scripts need r/w access to /usr currently, there is no easy
solution (like unpacking first, remounting, then configuring). An option
would be to split the postinst process. Since not many packages should
need to modify files on /usr in the postinst, this would be actually
doable, however I'm not sure about whether this is actually wanted.
Simon
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Received: (at 78834-done) by bugs.debian.org; 13 Dec 2000 14:58:42 +0000
>From wichert@cistron.nl Wed Dec 13 08:58:41 2000
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Mon, 11 Dec 2000 19:58:33 +0100
Date: Mon, 11 Dec 2000 19:58:33 +0100
From: Wichert Akkerman <wichert@valinux.com>
To: Simon Richter <Simon.Richter@phobos.fachschaften.tu-muenchen.de>,
78834-done@bugs.debian.org
Subject: Re: Bug#78834: Support for mounting /usr readonly
Message-ID: <20001211195833.N4346@cistron.nl>
References: <[🔎] Pine.LNX.4.21.0012051514210.20290-100000@phobos.fachschaften.tu-muenchen.de>
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In-Reply-To: <[🔎] Pine.LNX.4.21.0012051514210.20290-100000@phobos.fachschaften.tu-muenchen.de>; from Simon.Richter@phobos.fachschaften.tu-muenchen.de on Tue, Dec 05, 2000 at 03:23:23PM +0100
Delivered-To: 78834-done@bugs.debian.org
Previously Simon Richter wrote:
> However, this approach only works as long as no postinst script starts a
> daemon on /usr. After that, the filesystem is marked busy and cannot be
> properly remounted read-only.
Any daemon that doesn't do the following is basically broken:
1. chdir to /
2. close stdin/stdout/stderr and if needed reopen then to /dev/null
3. start a new session group (setsid)
If you find a daemon that doesn't do that feel free to submit a
bugreport.
> As postinst scripts need r/w access to /usr currently, there is no easy
> solution (like unpacking first, remounting, then configuring). An option
> would be to split the postinst process. Since not many packages should
> need to modify files on /usr in the postinst, this would be actually
> doable, however I'm not sure about whether this is actually wanted.
The postinst might need a writeable /usr, there is no way around that.
Remount /usr after running all the postinsts.
Wichert.
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