Now it's really interesting. If I just try to boot the system with the disk labeled xvda, I get a huge series of kernel panics (see below.) If I change it to sda (in both the config file and grub) it looks like it might work, but then I get:
Freeing unused kernel memory: 124k freed
SCSI subsystem initialized
Registering block device major 8
register_blkdev: cannot get major 8 for sd
xen_blk: can't get major 8 with name sd
vbd vbd-2048: 19 xlvbd_add at /local/domain/0/backend/vbd/27/2048
Registering block device major 8
register_blkdev: cannot get major 8 for sd
xen_blk: can't get major 8 with name sd
vbd vbd-2048: 19 xlvbd_add at /local/domain/0/backend/vbd/27/2048
XENBUS: Timeout connecting to device: device/vbd/2048 (state 6)
device-mapper: 4.5.5-ioctl (2006-12-01) initialised: dm-devel@redhat.com
Kernel panic - not syncing: Attempted to kill init!
FYI, this wasn't a Xensource kernel before, it was actually a Fedora 5 kernel (2.6.15-1.2054_FC5xenU) I created a yum repository for RHEL4 with the Fedora kernel, and used it to set up the box.
Kernel panics (lots of them, all the same):
kernel BUG at arch/i386/mm/pgtable-xen.c:306!
invalid operand: 0000 [#1]
SMP
Modules linked in: ext3 jbd dm_mod xenblk sd_mod scsi_mod
CPU: 0
EIP: 0061:[<c011163a>] Not tainted VLI
EFLAGS: 00010282 (2.6.9-55.0.9.ELxenU)
EIP is at pgd_ctor+0x1d/0x26
eax: fffffff4 ebx: 00000000 ecx: f5392000 edx: 00000000
esi: c19fdd80 edi: eca6aaa0 ebp: 00000001 esp: ecb3cd6c
ds: 007b es: 007b ss: 0068
Process 10-udev.hotplug (pid: 398, threadinfo=ecb3c000 task=ecb2a070)
Stack: c0141b69 ecb4b000 c19fdd80 00000001 ecb4b000 eca6aaa0 c19fdd80 c19fde40
c0141ceb c19fdd80 eca6aaa0 00000001 c19fdd80 eca6aaa0 ecb4b000 00000010
00000001 000000d0 c1a1b080 0000000c c19fde08 c19fdd80 c0141eda c19fdd80
Call Trace:
[<c0141b69>] cache_init_objs+0x35/0x56
[<c0141ceb>] cache_grow+0xfb/0x187
[<c0141eda>] cache_alloc_refill+0x163/0x19c
[<c01420f5>] kmem_cache_alloc+0x67/0x97
[<c0111671>] pgd_alloc+0x17/0x336
[<c01199d4>] mm_init+0xd7/0x116
[<c01199e4>] mm_init+0xe7/0x116
[<c0119c8a>] copy_mm+0xbb/0x396
[<c0268f10>] __cond_resched+0x14/0x3c
[<c011aa5a>] copy_process+0x6b5/0xb0b
[<c011af9d>] do_fork+0x8a/0x16b
[<c0107507>] error_code+0x2b/0x30
[<c0105d2c>] sys_clone+0x24/0x28
[<c010737f>] syscall_call+0x7/0xb
Code: 74 02 66 a5 a8 01 74 01 a4 5e 5b 5e 5f c3 80 3d 04 07 2f c0 00 75 1c 6a 20 6a 00 ff 74 24 0c e8 ce 37 00 00 83 c4 0c 85 c0 74 08 <0f> 0b 32 01 b6 31 27 c0 c3 80 3d 04 07 2f c0 00 75 0d c7 44 24
<0>Fatal exception: panic in 5 seconds
----- Original Message -----
From: "Chris Lalancette" <clalance@redhat.com>
To: "Jim Klein" <jklein@saugus.k12.ca.us>
Cc: "fedora-xen" <fedora-xen@redhat.com>
Sent: Tuesday, October 30, 2007 3:00:05 PM (GMT-0800) America/Los_Angeles
Subject: Re: [Fedora-xen] RHEL4 DomU Update Problem
Jim Klein wrote:
> Interesting:
>
> XENBUS: Device with no driver: device/vbd/2048
> XENBUS: Device with no driver: device/vif/0
> Freeing unused kernel memory: 124k freed
> device-mapper: 4.5.5-ioctl (2006-12-01) initialised: dm-devel@redhat.com
> Kernel panic - not syncing: Attempted to kill init!
>
> Not sure where to go from here.
>
Believe it or not, those XENBUS errors are actually expected; the xenbus driver
is loaded before the virtual disk/network drivers, and it sees that it has these
nodes without drivers.
However, that does lead me to an idea. If I remember correctly, the Xensource
kernels have all of the drivers built-in, while we prefer to do things more
modular. I'm guessing that you didn't have the right driver in
/etc/modprobe.conf when the kernel was installed, so the initrd doesn't have the
right drivers in it. So what you'll want to do is:
1) Boot the RHEL-4 domU into the (working) Xen kernel.
2) Edit /etc/modprobe.conf, and add:
alias scsi_hostadapter xenblk
3) Remove the RedHat RHEL-4 kernel (rpm -e), and install it again, which should
re-generate the initrd with the right stuff in it.
Chris Lalancette