Another great thing with RO /usr is that you can harden the
permissions of some commands and be sure that your stuff stays
intact. And you are sure nobody installs their own stuff system-wide.
But you don't need to share a /usr to benifit the RO /usr...
On 27-Jul-2006, at 16:47, Nix, Robert P. wrote:
Not only would you have to shut down all the guests to introduce
your maintenance (although not during the actual "apply"; you could
allocate new disks, copy the old ones, and apply your maintenance
there, then switch everybody over), you'd also have to find a way
of tracking changes the maintenance made to the writable directory
paths, such as /etc. These would be the changes that would bite you
in the rear.
This type of set-up was done initially, in order to share a common /
usr filesystem (I'm not sure the others are really large enough to
make a big difference, space and cache -wise). But maintaining the
system, especially the parts and pieces outside the shared
filesystem, becomes a nightmare, because you can't just use the
tools supplied by the vendor to do the maintenance; you have to do
something extra to catch all the extra fallout. I think, for this
reason, most people have abandoned the shared /usr concept, and are
just allocating the space and maintaining each system as if it was
a stand-alone box. I could be wrong, though.
But you are going through the same thought process that everyone
else has at some point in this process, so you're in good company.
--
.~. Robert P. Nix Mayo Foundation
/V\ RO-OC-1-13 200 First Street SW
/( )\ 507-284-0844 Rochester, MN 55905
^^-^^ -----
"In theory, theory and practice are the same, but
in practice, theory and practice are different."
-----Original Message-----
From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf
Of MOEUR TIM C
Sent: Thursday, July 27, 2006 9:45 AM
To: [email protected]
Subject: Shared common Directories
Hello List,
I'm pursuing an architecture for multiple guests under VM and I'd like
to know if anyone else has done the same, or if this is just an
accident
waiting to happen. I invite your thoughts, comments, and witty
remarks.
Here's what I'm considering: I'd like to create multiple VM Linux
guests that each have read access to a set of common minidisks. On
those common minidisks will be what I'm calling the shared Linux file
systems, such as stuff in /sbin, /bin, /boot, /lib. Each VM Linux
guest will also have an exclusive minidisk (WRITE) that will
contain the
file systems needed to update and operate (/etc, /proc, /sys, /tmp and
so on). The assumption is that each Linux guest will use the same
level
of OS, patches, and add-on programs.
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