Hello,
I
am no xen or generally linux expert and I do not understand clearly everything
You write, but at least some from Your requirements seem for me to be
realizable by the DomU installed on the logical volume. Always you want to
start Your new VM, You can create a new writable snapshot logical volume of the
original logical volume (as far as I kow at least theoretically, it is
possible). So You can run a lot of such „snapshot“ DomUs which all
base on same original data. If You want to modify the original data, You can
just start the original DomU, modify the original DomU VM (install new
software, etc) and if the original DomU is modified, then shut down this „original“
DomU and use the original logical volume – now in consistent new state - again
for the start of the „snapshot“ DomUs...
You
can then compare the original logical volume with the modified snapshot volume
and so find out which files – or data on the logical volume – have
been changed.
I
think, there are also the tools in Windows which can log the disc/files/registry
accesses and modifications, so You can install it by default on the Original DomU
and then it will log all Your modifications in every started „snapshot“
DomU... But I do not know exactly which tool it is, there are just some
monitoring tools for this purpose, look in the internet for them.
Of
course, You have written You know how to make it in Linux, so maybe this way is
not suitable for You – but from Your questions I do not understand
exactly why it is not possible to make it in the way I described... Maybe I am
wring – like written, I am not an expert.... :-)
With
regards
Archie
From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
[mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Jim Burnes
Sent: Tuesday, June 19, 2007 10:29 PM
To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-users] Hard Problem /w XenSource / XenEnterprise.
Hi,
Our group would really like to use XenSource to run a very large number of
parallel Windows XP VMs, but there are several issues we need to overcome or
else we'll have to use ESX instead. This is pretty high priority so if
there is a high-level tech at XenSource who knows how to solve this, we would
be really grateful.
(1) We want to start-up using a post-boot save of Windows XP and the run a
software test envrionment in the VM where any file write to the boot drive
(misc, registry etc) is written to a spool/log (similar to a file system
journal) so that writes don't corrupt our common XP image.
(2) When we shut down the VM we still need access to the journal so we can do a
"diff" on what happened during testing. I know its possible to
use some sort of system shim to catch OS writes, but we want to keep OS
modification to a minimum.
Whether we do this via some sort of shim into an OS callgate we still need to
make various read/writes to the common shared image transparent /
non-corrupting of the shared image.
I know how to do that in Linux. You use variously overlay file
systems. How do you do it in Windows.
In other words, we have a very nice potential demonstration system for
XenEnterprise/XenSource. I'd like to talk to a senior tech about the deep
tech issues. As much as I like to talk to Sales people about this, these
are *very deep* technical issues. I would appreciate a pointer though if
you know the engineer to talk to.
Jim Burnes
