Re: maintaining many Xen VMs

[Paul Ripke <stix%stix.id.au@localhost>]

On Thu, Oct 19, 2006 at 01:39:15PM -0400, Steven M. Bellovin wrote:
> I recently brought up 3 DomUs; the result, of course, is that I now have 3
> more machines to administer.  This is known as a bad tradeoff...  I'm
> curious, though, how other people are solving this.
> 
> My (NetBSD) DomUs are going to be mostly identical.  I was thinking of
> having a shared, read-only /usr and separate /var.  I probably need
> separate roots, if only to have separate /etc/rc.conf files.  /usr will be
> a real partition, probably shared with the Dom0.  The Dom0 would also have
> a separate partition that held the vnds for the DomUs.

Another option to keep in mind is 'vfs.generic.magiclinks=1',
enabling system-specific copies of system config files. After working
with a Tru64 cluster at work, I can see lots of practical uses. Eg.
I'm using it for system-specific .screenrc in an NFS mounted home
directory:

ksh$ ls -l .screenrc*
lrwxr-xr-x  1 stix  users    21 Oct 18 15:33 .screenrc -> .screenrc.@{hostname}
-rw-r--r--  1 stix  users   255 Oct 18 15:32 .screenrc.hactar.stix.org.au
-rw-r--r--  1 stix  users   254 Oct 18 15:31 .screenrc.kitt.stix.org.au
-rw-r--r--  1 stix  users   254 Oct 18 15:32 .screenrc.orac.stix.org.au
-rw-r--r--  1 stix  users   318 Oct 18 17:52 .screenrc.zion.stix.org.au

Cheers,
-- 
Paul Ripke
Unix/OpenVMS/TSM/DBA
I love deadlines. I like the whooshing sound they make as they fly by.
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