Comments on: Xen: NetBSD VM on a Debian Dom0 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/ Open Source, The Web, And German-American Oddities Fri, 21 Nov 2008 23:43:54 +0000 http://wordpress.org/?v=2.6.3 By: Witek http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-169131 Witek Thu, 10 Jul 2008 13:14:31 +0000 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-169131 Latests INSTALL_XEN3PAE_DOMU snapshots are crashing on boot. :( Is it still working (and i'm doing something wrong) or is it regression? (XEN) domain_crash_sync called from entry.S (ff15b6a9) (XEN) Domain 32 (vcpu#0) crashed on cpu#1: (XEN) ----[ Xen-3.0.3-1 x86_32p debug=n Not tainted ]---- (XEN) CPU: 1 (XEN) EIP: e019:[] (XEN) EFLAGS: 00000202 CONTEXT: guest (XEN) eax: 00000000 ebx: 00000000 ecx: 00000001 edx: c043fa74 (XEN) esi: 00000000 edi: 000024a8 ebp: c0437e44 esp: c0437e08 (XEN) cr0: 8005003b cr4: 000002f0 cr3: 41fe1000 cr2: 00000001 (XEN) ds: e021 es: e021 fs: 0000 gs: 0000 ss: e021 cs: e019 (XEN) Guest stack trace from esp=c0437e08: (XEN) 00000000 c03972b9 0001e019 00010002 c0397393 00000000 00000000 00000000 (XEN) 00000000 00000000 00000000 00000000 00000000 c042e734 000024a8 c0437e74 (XEN) c02f451f 00000000 00000005 00000000 00000000 c0437e80 00000000 00000000 (XEN) 00000000 c0437e80 00000100 c0437eb4 c02f461e c0422b5b 00000000 c0923f00 (XEN) 00000000 00000000 00000000 00000000 00000000 00000000 c0a2a000 00000000 (XEN) c0437ec0 c0437f48 00007ff0 c0437f64 c0396e22 c042e734 c0a2e000 00001000 (XEN) 00000000 0092e000 00000000 00000000 00000000 00000000 00000008 c0a2a000 (XEN) c0a1d000 c0a2b000 c0a351b0 00000000 c0a2b000 0092f000 00000000 c0e00000 (XEN) c0a30000 c0437000 c0a37000 00000007 000024d8 00a2a000 00000000 00000606 (XEN) c0a37000 0092e000 00000000 00000000 c0a37000 c0a25000 c0a30000 00000000 (XEN) 00000002 0002cff2 00000000 00000000 c0a2a000 00000001 00000007 c0437f94 (XEN) c0396f36 00000007 00000000 00000000 00000008 c0a2a000 c0a1d000 00000007 (XEN) 756e6547 c0a1a200 c09a4740 00000000 c0100041 00000000 00000000 c03f20e0 (XEN) 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 (XEN) 00000000 00000000 00000000 00000000 c03f25e0 00000000 c03f2360 c03f2500 (XEN) c03ecce0 00000000 00000000 00000000 00000000 00000000 dom0# uname -a Linux noisy 2.6.18-6-xen-686 #1 SMP Sat Jun 7 02:07:48 UTC 2008 i686 GNU/Linux Latests INSTALL_XEN3PAE_DOMU snapshots are crashing on boot. :( Is it still working (and i’m doing something wrong) or is it regression?

(XEN) domain_crash_sync called from entry.S (ff15b6a9)
(XEN) Domain 32 (vcpu#0) crashed on cpu#1:
(XEN) —-[ Xen-3.0.3-1 x86_32p debug=n Not tainted ]—-
(XEN) CPU: 1
(XEN) EIP: e019:[]
(XEN) EFLAGS: 00000202 CONTEXT: guest
(XEN) eax: 00000000 ebx: 00000000 ecx: 00000001 edx: c043fa74
(XEN) esi: 00000000 edi: 000024a8 ebp: c0437e44 esp: c0437e08
(XEN) cr0: 8005003b cr4: 000002f0 cr3: 41fe1000 cr2: 00000001
(XEN) ds: e021 es: e021 fs: 0000 gs: 0000 ss: e021 cs: e019
(XEN) Guest stack trace from esp=c0437e08:
(XEN) 00000000 c03972b9 0001e019 00010002 c0397393 00000000 00000000 00000000
(XEN) 00000000 00000000 00000000 00000000 00000000 c042e734 000024a8 c0437e74
(XEN) c02f451f 00000000 00000005 00000000 00000000 c0437e80 00000000 00000000
(XEN) 00000000 c0437e80 00000100 c0437eb4 c02f461e c0422b5b 00000000 c0923f00
(XEN) 00000000 00000000 00000000 00000000 00000000 00000000 c0a2a000 00000000
(XEN) c0437ec0 c0437f48 00007ff0 c0437f64 c0396e22 c042e734 c0a2e000 00001000
(XEN) 00000000 0092e000 00000000 00000000 00000000 00000000 00000008 c0a2a000
(XEN) c0a1d000 c0a2b000 c0a351b0 00000000 c0a2b000 0092f000 00000000 c0e00000
(XEN) c0a30000 c0437000 c0a37000 00000007 000024d8 00a2a000 00000000 00000606
(XEN) c0a37000 0092e000 00000000 00000000 c0a37000 c0a25000 c0a30000 00000000
(XEN) 00000002 0002cff2 00000000 00000000 c0a2a000 00000001 00000007 c0437f94
(XEN) c0396f36 00000007 00000000 00000000 00000008 c0a2a000 c0a1d000 00000007
(XEN) 756e6547 c0a1a200 c09a4740 00000000 c0100041 00000000 00000000 c03f20e0
(XEN) 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
(XEN) 00000000 00000000 00000000 00000000 c03f25e0 00000000 c03f2360 c03f2500
(XEN) c03ecce0 00000000 00000000 00000000 00000000 00000000

dom0# uname -a
Linux noisy 2.6.18-6-xen-686 #1 SMP Sat Jun 7 02:07:48 UTC 2008 i686 GNU/Linux

]]> By: Michael Marineau http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116270 Michael Marineau Mon, 18 Feb 2008 19:42:25 +0000 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116270 Not really, there is limited support for x86 domU which lacks useful things like live migration and memory resizing. Both x86_64 and dom0 support don't quite exist yet for mainline's paravirt ops interface but thankfully redhat recently started this work. The upstream xen people do their development on 2.6.18 which predates paravirt ops. Not really, there is limited support for x86 domU which lacks useful things like live migration and memory resizing. Both x86_64 and dom0 support don’t quite exist yet for mainline’s paravirt ops interface but thankfully redhat recently started this work. The upstream xen people do their development on 2.6.18 which predates paravirt ops.

]]> By: Fred http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116149 Fred Mon, 18 Feb 2008 09:10:32 +0000 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116149 @Mike: By the way I do think Xen has made it into the mainline kernel in 2.6.23: http://kerneltrap.org/node/13917 @Mike: By the way I do think Xen has made it into the mainline kernel in 2.6.23: http://kerneltrap.org/node/13917

]]> By: Fred http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116132 Fred Mon, 18 Feb 2008 08:16:14 +0000 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116132 Haha, okay -- what I didn't mention is that there were other reasons for this setup, mainly security reasons and also the comfort of being able to "make" a new box without actually buying hardware. So yeah, I should have mentioned that the decision to use Xen came first, and afterwards I realized that building a Xen domU Kernel that also supports "foreign" binaries and happens to turn out stable is less than trivial ;) Haha, okay — what I didn’t mention is that there were other reasons for this setup, mainly security reasons and also the comfort of being able to “make” a new box without actually buying hardware. So yeah, I should have mentioned that the decision to use Xen came first, and afterwards I realized that building a Xen domU Kernel that also supports “foreign” binaries and happens to turn out stable is less than trivial ;)

]]> By: Michael Marineau http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116117 Michael Marineau Mon, 18 Feb 2008 07:22:00 +0000 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116117 Wow, that is quite the setup just to avoid building your own kernels which really isn't that hard. Debian even has make-kpkg so you can easily build debs for your custom kernel. imho it will be a lot easier to maintain a system with a custom kernel than dealing with Xen. Until some day when Xen dom0 support gets merged into mainline (might actually happen now that Redhat is working on it, Xen upstream doesn't care it seems) you are stuck with either a hopelessly out of date kernel (2.6.18) or a hopelessly forward ported kernel (2.6.21 at best as far as I know). But good luck to you! :-) Wow, that is quite the setup just to avoid building your own kernels which really isn’t that hard. Debian even has make-kpkg so you can easily build debs for your custom kernel. imho it will be a lot easier to maintain a system with a custom kernel than dealing with Xen. Until some day when Xen dom0 support gets merged into mainline (might actually happen now that Redhat is working on it, Xen upstream doesn’t care it seems) you are stuck with either a hopelessly out of date kernel (2.6.18) or a hopelessly forward ported kernel (2.6.21 at best as far as I know). But good luck to you! :-)

]]> By: Fred http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116004 Fred Sun, 17 Feb 2008 22:02:40 +0000 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116004 Thanks for the comment, chithanh. I read this too today: people who need tons of RAM and want to run Xen usually just switch to appropriate hardware, which I believe makes sense, as PAE is highly likely to perform worse than a system that can handle more RAM by design. Thanks for the comment, chithanh. I read this too today: people who need tons of RAM and want to run Xen usually just switch to appropriate hardware, which I believe makes sense, as PAE is highly likely to perform worse than a system that can handle more RAM by design.

]]> By: chithanh http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116001 chithanh Sun, 17 Feb 2008 21:29:18 +0000 http://fredericiana.com/2008/02/17/xen-netbsd-vm-on-a-debian-dom0/#comment-116001 Note that PAE is quite a crutch and due to kernel/userland memory split memory performance suffers on 32-bit systems with 2GB or more RAM. So use amd64 if your hardware supports it and you want lots of RAM. Note that PAE is quite a crutch and due to kernel/userland memory split memory performance suffers on 32-bit systems with 2GB or more RAM. So use amd64 if your hardware supports it and you want lots of RAM.

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