Debian with read-only /usr
I'm looking at NFS-mounting /usr for a largish number of machines, with the basic idea that then I can just keep the binaries on the central server up-to date and the workstations will all follow along with (hopefully) a minimum of effort. I'm a little concerned about apt, though... I wouldn't expect it to be very open-minded about /usr being read-only. OTOH, I probably wouldn't need to run apt very often on the workstations unless there's a change to config file formats or an all-new package is being installed. Any Debian-specific advice on running a setup like that? -- Linux will do for applications what the Internet did for networks. - IBM, Peace, Love, and Linux Geek Code 3.1: GCS d? s+: a- C++ UL++$ P+ L+++ E- W--(++) N+ o+ !K w---$ O M- V? PS+ PE Y+ PGP t 5++ X+ R++ tv b+ DI D G e* h+ r y+
Re: Debian with read-only /usr
Dave - You could always mount the `/usr' filesystem on the server as readonly and use the `remount' option of `mount' to remount `/usr' as writeable during an apt upgrade. The other option would be to export `/usr' readonly, i.e., in the `/etc/exports' on the server. Dave Sherohman said on March 15, 2001 at 10:22 (-0600) I'm looking at NFS-mounting /usr for a largish number of machines, with the basic idea that then I can just keep the binaries on the central server up-to date and the workstations will all follow along with (hopefully) a minimum of effort. I'm a little concerned about apt, though... I wouldn't expect it to be very open-minded about /usr being read-only. OTOH, I probably wouldn't need to run apt very often on the workstations unless there's a change to config file formats or an all-new package is being installed. Any Debian-specific advice on running a setup like that? -- Linux will do for applications what the Internet did for networks. - IBM, Peace, Love, and Linux Geek Code 3.1: GCS d? s+: a- C++ UL++$ P+ L+++ E- W--(++) N+ o+ !K w---$ O M- V? PS+ PE Y+ PGP t 5++ X+ R++ tv b+ DI D G e* h+ r y+ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED] -- Carl Greco [EMAIL PROTECTED]
Re: Debian with read-only /usr
At 10:22 AM 3/15/01 , you wrote: I'm looking at NFS-mounting /usr for a largish number of machines, with the basic idea that then I can just keep the binaries on the central server up-to date and the workstations will all follow along with (hopefully) a minimum of effort. I'm a little concerned about apt, though... I wouldn't expect it to be very open-minded about /usr being read-only. OTOH, I probably wouldn't need to run apt very often on the workstations unless there's a change to config file formats or an all-new package is being installed. Any Debian-specific advice on running a setup like that? Just remount it rw before you run apt. If you only run it every couple of weeks that won't be a problem. Ben
Re: Debian with read-only /usr
On Thu, Mar 15, 2001 at 11:07:27AM -0600, Carl Greco wrote: You could always mount the `/usr' filesystem on the server as readonly and use the `remount' option of `mount' to remount `/usr' as writeable during an apt upgrade. The other option would be to export `/usr' readonly, i.e., in the `/etc/exports' on the server. I was unclear in my question... I'm definitely planning to do a read-only export from the server. My concern is with how apt will behave if/when run on the workstations, where /usr will be forced to be ro by the ro export. Many packages include files in /var, /etc, and/or other places besides /usr, some of which (like /etc) are not well-suited to being mounted off a common NFS directory. Running apt seems like the most straightforward way to get those files installed/updated, but it will also want to change things in /usr, but be unable to do so. -- Linux will do for applications what the Internet did for networks. - IBM, Peace, Love, and Linux Geek Code 3.1: GCS d? s+: a- C++ UL++$ P+ L+++ E- W--(++) N+ o+ !K w---$ O M- V? PS+ PE Y+ PGP t 5++ X+ R++ tv b+ DI D G e* h+ r y+
Re: Debian with read-only /usr
On Thu, Mar 15, 2001 at 10:22:47AM -0600, Dave Sherohman wrote:
I'm looking at NFS-mounting /usr for a largish number of machines, with the
basic idea that then I can just keep the binaries on the central server up-to
date and the workstations will all follow along with (hopefully) a minimum of
effort. I'm a little concerned about apt, though... I wouldn't expect it to
be very open-minded about /usr being read-only. OTOH, I probably wouldn't
need to run apt very often on the workstations unless there's a change to
config file formats or an all-new package is being installed.
Any Debian-specific advice on running a setup like that?
# cat /etc/apt/apt.conf
DPkg
{
// Auto re-mounting of a readonly /usr
Pre-Invoke {mount -o remount,rw /usr;};
Post-Invoke {mount -o remount,ro /usr;};
}
--
Eric G. Miller egm2@jps.net
RE: Debian with read-only /usr
UNSUBSCRIBE ME PLEASE!!
-Mensaje original-
De: Eric G. Miller [mailto:[EMAIL PROTECTED]
Enviado el: jueves, 15 de marzo de 2001 17:52
Para: Debian-User
CC: Dave Sherohman
Asunto: Re: Debian with read-only /usr
On Thu, Mar 15, 2001 at 10:22:47AM -0600, Dave Sherohman wrote:
I'm looking at NFS-mounting /usr for a largish number
of machines, with the
basic idea that then I can just keep the binaries on
the central server up-to
date and the workstations will all follow along with
(hopefully) a minimum of
effort. I'm a little concerned about apt, though...
I wouldn't expect it to
be very open-minded about /usr being read-only.
OTOH, I probably wouldn't
need to run apt very often on the workstations unless
there's a change to
config file formats or an all-new package is being installed.
Any Debian-specific advice on running a setup like that?
# cat /etc/apt/apt.conf
DPkg
{
// Auto re-mounting of a readonly /usr
Pre-Invoke {mount -o remount,rw /usr;};
Post-Invoke {mount -o remount,ro /usr;};
}
--
Eric G. Miller egm2@jps.net
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of unsubscribe. Trouble? Contact
[EMAIL PROTECTED]
Re: Debian with read-only /usr
On Thu, Mar 15, 2001 at 12:41:23PM -0600, Dave Sherohman wrote: I was unclear in my question... I'm definitely planning to do a read-only export from the server. My concern is with how apt will behave if/when run on the workstations, where /usr will be forced to be ro by the ro export. Many packages include files in /var, /etc, and/or other places besides /usr, some of which (like /etc) are not well-suited to being mounted off a common NFS directory. Running apt seems like the most straightforward way to get those files installed/updated, but it will also want to change things in /usr, but be unable to do so. apt itself doesn't care since it doesn't touch the filesystem except for /var/cache/apt and /var/state/apt. the problem comes when apt asks dpkg to install a package, if the package has any file in /usr (which it always will even if its only /usr/share/doc/package/*) then dpkg will fail and the package will be broken. newwer versions of dpkg (may only be in CVS) i have heard have an option to not install files in certain places, say /usr or /usr/share. to allow for this very situtation. for now pretty much your only option is this kludge: drop to single user mode umount /usr apt-get rm -rf /usr/* mount /usr -- Ethan Benson http://www.alaska.net/~erbenson/ pgpjCaFuz8On7.pgp Description: PGP signature
