Re: Scrubbing free ram

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, May 05, 2010 at 03:00:42PM +0800, Bei Guan wrote:
> Hi, Konrad,
> 
> Thank you for your reply.
> 
> I think it is hard to solve the problem of installing xen4.0 on
> fedora11_x86-32bit. Because everytime I install xen4.0 and reboot, my screen
> stopped at the below messages and did not to print anything.
> 
> (XEN) traps.c:2309:d0 Domain attempted WRMSR 000002ff from 00000000:00000c06
> > to 00000000:00000000.

Right. And if you used the Linux and Xen kernel command line options to
enable more debug option that Pasi and I've pointed you to
you would have seen more. They are in
http://wiki.xensource.com/xenwiki/XenParavirtOps under the section
titled "Are there more debugging options I could enable to troubleshoot
booting problems?" where it gives you an example:

xen-4.0.gz dom0_mem=1024M loglvl=all guest_loglvl=all sync_console console_to_ring com1=115200,8n1 console=com1 lapic=debug apic_verbosity=debug apic=debug iommu=off

vmlinuz-2.6.32.9 ro root=/dev/vg00/lv01 console=hvc0 earlyprintk=xen nomodeset initcall_debug debug loglevel=10

> 
> 
> 
> Now, I change my domain0 OS to fedora11_x86-64bit and I can successfully
> install the xen 4.0. However I have another problem. When I running the

So you solved your problem by building the 64-bit Dom0. Is your
userspace 64-bit or is it 32-bit? When you say 'change my domain0' was
that a re-install of Fedora Core 11?

> command "xend start", I got the error messages:
> 
> [root@localhost ~]# xend start
> ERROR Internal error: Could not obtain handle on privileged command

Run 'modprobe xenfs' and 'modprobe xen-evtchn' 

> interface (2 = No such file or directory)
> Traceback (most recent call last):
>   File "/usr/sbin/xend", line 36, in <module>
>     from xen.xend.server import SrvDaemon
>   File "usr/lib64/python2.6/site-packages/xen/xend/server/SrvDaemon.py",
> line 26, in <module>
>   File "usr/lib64/python2.6/site-packages/xen/xend/server/relocate.py", line
> 28, in <module>
>   File "usr/lib64/python2.6/site-packages/xen/xend/XendDomain.py", line 36,
> in <module>
>   File "usr/lib64/python2.6/site-packages/xen/xend/XendCheckpoint.py", line
> 20, in <module>
>   File "usr/lib64/python2.6/site-packages/xen/xend/image.py", line 46, in
> <module>
> xen.lowlevel.xc.Error: (1, 'Internal error', 'Could not obtain handle on
> privileged command interface (2 = No such file or directory)')
> 
> I googled the problem and found it seems to be a bug, which refered here:
> http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1436
> 
> 
> 
> If I running another command "/etc/init.d/xend start", it can successfully
> start the xend service. But I can not create a PV DomU or HVM DomU. The
> error message as following.

That one is fairly easy. You don't have the right 'root' entry for your
guest (you are missing the right root="/dev/<something, something>").

It looks to be that you are trying to do '/dev/sda1' but since you
changed your disk=['...'] entry to have 'xvda', it should be
'/dev/xvda1'

> 
> 1. Error of starting a PV DomU
> [root@localhost ubuntu-32]# xm create ubuntu.9-04.x86.xen3.cfg -c
> ……  ……
> [    1.831122] Sending DHCP requests ...
> [   14.320061] ... timed out!
> [   75.986391] IP-Config: Reopening network devices...
> [   77.488086] Sending DHCP requests ...
> [   93.965059] ... timed out!
> [  165.740440] IP-Config: Auto-configuration of network failed.
> [  165.740565] md: Waiting for all devices to be available before autodetect
> [  165.740587] md: If you don't use raid, use raid=noautodetect
> [  165.741555] md: Autodetecting RAID arrays.
> [  165.741577] md: Scanned 0 and added 0 devices.
> [  165.741596] md: autorun ...
> [  165.741614] md: ... autorun DONE.
> [  165.741921] Root-NFS: No NFS server available, giving up.
> [  165.741984] VFS: Unable to mount root fs via NFS, trying floppy.
> [  165.742429] VFS: Cannot open root device "sda1" or unknown-block(2,0)
> [  165.742452] Please append a correct "root=" boot option; here are the
> available partitions:
> [  165.742529] ca01         1025024 xvda1 driver: vbd

                                      ^^^^ - use that one instead of
sda1

> [  165.742566] Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(2,0)
> [  165.742590] Pid: 1, comm: swapper Not tainted 2.6.31.13 #1
> [  165.742610] Call Trace:
> [  165.742642]  [<ffffffff81591fd2>] panic+0x75/0x130
> [  165.742674]  [<ffffffff8195fafe>] mount_block_root+0x1ce/0x1e5
> [  165.742705]  [<ffffffff8195fb80>] mount_root+0x6b/0x8b
> [  165.742734]  [<ffffffff8195fd10>] prepare_namespace+0x170/0x19d
> [  165.742765]  [<ffffffff8195efc0>] kernel_init+0x1b5/0x1c5
> [  165.742797]  [<ffffffff81033dea>] child_rip+0xa/0x20
> [  165.742827]  [<ffffffff81032fa7>] ? int_ret_from_sys_call+0x7/0x1b
> [  165.742858]  [<ffffffff8103375d>] ? retint_restore_args+0x5/0x6
> [  165.742889]  [<ffffffff81033de0>] ? child_rip+0x0/0x20
> 
> (Attached is the complete messages)
> 
> 2. Error of starting a HVM DomU
> [root@localhost windowsxp]# xm create winxp2_xen4.hvm
> Using config file "./winxp2_xen4.hvm".
> Error: Domain 'WinXP_HVMDomain' does not exist.
> 
> ("WinXP_HVMDomain" is my HVM DomU name)

No idea without cranking up some debug options. Look up
http://wiki.xensource.com/xenwiki/XenParavirtOps at the debug option.