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we've installed Debian "Wheezy" on a machine previously running "Squeeze". We were running Xen (4.0.1, Squeeze's version) without problems, but after we upgraded to Wheezy (Xen 4.1) the machine reboots just after kernel loading (it seems the kernel loads OK, but something right afterwards makes it reboot).

What baffles me the most is that the "VRM" light of the Light Path switches on red just when it happens. According to this page, VRM is the acronym of Voltage Regulator Module, and the light could imply that "a DC-DC regulator has failed or is missing". I don't know what that can mean, but it's a constant with this problem.

Also, I used the expression "hard reboot" because it really looks like that: the fans make a lot of noise just after the reboot, as if the machine had just been switched on. Scary stuff.

More data: we've tried Ubuntu 12.04, XenServer 6 and the latest ISO from XCP, and they all do the same. So it must be something in Xen 4.1 that our x346 doesn't like at all.

This machine hasn't VT-x extensions. Could that be the problem? Do you have any tips that could help us to shed some light into the issue?

Thanks in advance.

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And it doesn't do this with straight Debian Squeeze, only after you install Xen? –  EightBitTony Nov 21 '12 at 18:07
@EightBitTony, not even with Xen from Debian Squeeze. It only happens when I use Xen 4.1, the one that comes with Debian Wheezy. –  rsuarez Nov 22 '12 at 11:17
Apologies, got my distributions confused. My question is - does it do it with the base OS install, or only after you've installed Xen? –  EightBitTony Nov 22 '12 at 16:14
@EightBitTony, only when booting with Xen 4.1's hypervisor. It's not a straight answer to your question, I know :-) It's after installing Xen, but not when booting with the standard kernel: just when booting with the hypervisor. –  rsuarez Nov 26 '12 at 12:35
(Sorry I did not find the way to contact you, so I post it here) I have got the same problem of rebooting with IBM x346, using Ubuntu 12.04 with Xen 4.1.2, or Ubuntu 12.10 with Xen 4.1.3. Have you found a solution to it? If yes, could share it with me? alan04@foxmail.com Thank you! P.S. I found a similiar scenario here: lists.debian.org/debian-user/2011/03/msg00504.html. it seems not work for me. –  Alan_04 Apr 5 '13 at 6:45

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