xen-devel — List for Xen developers

RE: [Xen-devel] Run X in other domains?

[Ian P. <m+I...@cl...>]

> Initially I made some progress with the pre-built kernel=20
> binaries (from the current 2.0.5 release).  The xenU kernel=20
> lacks PCI support, and X reports "Cannot open /dev/tty0"=20
> using it in domain 1.  I switched to the xen0 kernel for PCI=20
> support, and then X reported "Cannot find a free VT".
>=20
> The output from lspci lists everything but the VGA card in=20
> domain 0, unless "lspci -H 1" is used.  In other domains,=20
> lspci reports only the VGA card and "lspci -H 1" reports "You=20
> need to be root to have access to I/O ports".  However X=20
> still starts OK in domain 0, which surprised my.
> I've confirmed that "xm dmesg" includes "Hiding PCI device=20
> 01:00.0 from DOM0" after passing "physdev_dom0_hide=3D01:00.1" to Xen.

I can see how you could start a very simple VGA-only Xserver -- by
default dom0 happens to have access to the bottom 1MB of memory, which
is enough to get a VGA Xserver working.
=20
> I've followed Ian's advice, rebuilding Linux 2.6.10 with the=20
> default xenU configuration eith XEN_PHSDEV_ACCESS added (to=20
> automatically enable
> DUMMY_CONSOLE) plus PCI support.  However my kernel crashes=20
> immediately after "Freeing unused kernel memory", even when I=20
> pass "xencons=3DttyS".
> Perhaps the build broke somehow, or it's configuration is invalid?

I think you'll need to look through the oops message to see what's going
on.
You could try setting xencons=3Doff just to rule xencons out.

I presume you've granted the PCI device to the other domain in it's
config file?=20

Ian

Re: [Xen-devel] Run X in other domains?

[Sean A. <se...@ne...>]

Hi,

I've been looking into Xen's status recently, and trying to run X from a
non-privileged domain.  I'd got as far as Mark reported when I found his
old post on the mailing list, so thought I'd reply to this thread.
However I didn't find any follow ups after Ian's response, so I presume
there have been no developments for a while.

Initially I made some progress with the pre-built kernel binaries (from
the current 2.0.5 release).  The xenU kernel lacks PCI support, and X
reports "Cannot open /dev/tty0" using it in domain 1.  I switched to the
xen0 kernel for PCI support, and then X reported "Cannot find a free
VT".

The output from lspci lists everything but the VGA card in domain 0,
unless "lspci -H 1" is used.  In other domains, lspci reports only the
VGA card and "lspci -H 1" reports "You need to be root to have access to
I/O ports".  However X still starts OK in domain 0, which surprised my.
I've confirmed that "xm dmesg" includes "Hiding PCI device 01:00.0 from
DOM0" after passing "physdev_dom0_hide=01:00.1" to Xen.

I've followed Ian's advice, rebuilding Linux 2.6.10 with the default
xenU configuration eith XEN_PHSDEV_ACCESS added (to automatically enable
DUMMY_CONSOLE) plus PCI support.  However my kernel crashes immediately
after "Freeing unused kernel memory", even when I pass "xencons=ttyS".
Perhaps the build broke somehow, or it's configuration is invalid?

My domain config file looks like this:

kernel = "/boot/vmlinuz-2.6.10-xenU-mod"
memory = 128
name = "whitebox"
disk = [ 'phy:hda6,hda6,w' ]
root = "/dev/hda6 ro"
extra = "1 xencons=ttyS"
pci = [ '01,00,00' ]

Does anybody have any experience with X in other domains, or thoughts on
how I might proceed please?

Cheers,

Sean.


On Wed, 2004-08-25 at 09:02 +0100, Ian Pratt wrote: 
> > Trying out the various possibilities of Xen, I found a way to boot a
> > second domain with my secondary graphics and usb cards.In the second machine, the devices show up exactly as expected when using
> > lspci and lsusb, and cat /dev/mouse0 shows that the mouse generates
> > correct output.
> 
> Excellent, glad to hear it. Please could you post your config
> file as an example.
> 
> > So I decided to try and boot X within this machine, and adapted my X
> > config to match the PCI id of the second card, and use my USB mouse and
> > keyboard.However, when I try to startup X, it complains about being unable to
> > access a free tty...I had not honestly thought that this would instantly work, so it is not
> > really a surprise that it fails. However, this seems to me a bit of a
> > strange message, since obviously I am on tty1 of the machine, and it
> > should be able to start when I use 'vt1' as a start parameter, or am I
> > mistaken here?
> 
> I'm not really sure how things work with multiple graphics cards,
> but I presume one of them is initialised by the BIOS as the
> primary VGA device. I guess you've built the dom0 kernel with VGA
> support and it's using that as it's console.
> 
> Although the dom1 kernel can see the graphics card, you
> presumably don't build it with VGA console support because
> otherwise it would fight with dom0 for the single BIOS VGA
> console.
> 
> In dom1, you're probably having xencons register as tty1 and are
> using that as a console. It's not a VT, so I can see why X
> complains if that's what it's looking for. It presumably wants a
> VT so that it can play nice with other VGA text consoles.  I
> wander if it's possible to tell X just to go for it anyway?
> 
> If not, how about building dom1 with VT support but with the
> DUMMY console driver rather than VGA support.  So that you can
> still get a xen console on the domain you could start dom1 with
> xencons=ttyS on its kernel command line and add appropriate
> inittab and securetty entries for ttyS0. This should enable you
> to log in, and then when you start X it should be able to find a VT.
> 
> Please let us know how you get on.
> 
> Ian
> 
> 
> 
> Since domain0 h
> 
> 
> Anyway, it seems to me that this particular problem should not be that
> > hard to solve... if anyone can point me in the right direction, I can even
> > give it a try myself :-)
> >
> > Well any hints/tips on how to get X running in a second domain are welcome!
> >
> > Best wishes,
> > Mark.


-- 
Sean Atkinson <se...@ne...>
Netproject

[Xen-devel] save/restore problems

[Hari K. <har...@gm...>]

Hi All,

I am running into a bunch of problems when trying to do save/restore.
(I am NOT running the latest xen. I am running 2.0)

I am trying out the FC-1, and RH-ES-9 images. I can create domains for
all the three. But when I save some configurations of these images
(for example, install some rpms on a clean image and save the image)
and then restore them, I am running into the following issues:

(1) FC-1: The most success I have is with this. I can do save and
restore. But as soon as I execute a command remotely that modifies the
file system (e.g., "ssh -n hostname "do-some-fs-updates.sh"), it
starts complaining that the filesystem is read only. The error on the
console looks something like:

xen_blk:  Unexpected blkif status disconnected in state connected
blkfront: recovered 0 descriptors
nfs warning: mount version older than kernel
nfs warning: mount version older than kernel
EXT3-fs error (device sda1): ext3_free_blocks: bit already cleared for
block 293633
Aborting journal on device sda1.
ext3_abort called.
EXT3-fs error (device sda1): ext3_journal_start: Detected aborted journal
Remounting filesystem read-only
EXT3-fs error (device sda1) in start_transaction: Journal has aborted
ext3_reserve_inode_write: aborting transaction: Journal has aborted in
__ext3_journal_get_write_access<2>EXT3-fs error (device sda1) in
ext3_reserve_inode_write: Journal has aborted
ext3_reserve_inode_write: aborting transaction: Journal has aborted in
__ext3_journal_get_write_access<2>EXT3-fs error (device sda1) in
ext3_reserve_inode_write: Journal has aborted
EXT3-fs error (device sda1) in ext3_orphan_del: Journal has aborted
EXT3-fs error (device sda1) in ext3_truncate: Journal has aborted
EXT3-fs error (device sda1) in start_transaction: Journal has aborted
EXT3-fs error (device sda1) in start_transaction: Journal has aborted


Doing this a couple of times (shutdown and then restore again)
corrupts the fs and then i need to run fsck at boot time to get back
to normal status.


(2) RH-ES-9: The save command ("xm save RHES9 myRHES9") just hangs.
Does not do anything.


My question is whether this is something that anyone have seen before
and/or whether anyone could point me to why this happens here and/or
whether installing 2.0.5 would solve this for me.

Thanks
-Hari

Re: [Xen-devel] poor domU VBD performance.

[Pasi <pa...@ik...>]

On Sun, Mar 27, 2005 at 06:41:27PM +0100, Ian Pratt wrote:
> > I found out that dom0 does file-system IO and raw IO ( using=20
> > dd as a tool to test
> > throughput from the disk ) is about exactly the same as when=20
> > using a standard=20
> > linux kernel without XEN. But the raw IO from DomU to an=20
> > unused disk ( a second
> > disk in the system ) is limited to fourty percent of the=20
> > speed I get within Dom0.
>=20
> Just to be clear: you're doing a dd performance test within dom0 to the
> exact same partition on the 2nd disk that you're using when you start
> the domU and finding that the domU 'dd' performance is 40% of the dom0
> performance?
>=20
> I've not heard of anyone else having problems like this. What happens i=
f
> you use a partition on the 1st disk?
>=20
> What chipset is the IDE controller? What device (e.g. sda1) are you
> exporting the disk partition into the domU as?
>=20
> Are you sure dom 0 is idle when doing the dd test in the domU?
>=20

I reported same kind of problems earlier too.=20

2.4 domU is really slow (1/3 speed of 2.6 dom0), 2.6 domU is faster, but =
not even close=20
to the speed of 2.6 dom0.

My tests were on top lvm over sw-raid5.

-- Pasi K=E4rkk=E4inen
      =20
                                   ^
                                .     .
                                 Linux
                              /    -    \
                             Choice.of.the
                           .Next.Generation.

[Xen-devel] thread-safe xm commands

[Amitabh T. <tam...@ya...>]

Can I use the xm commands in a multi-threaded environment? 
Eg: If two threads call same xm command for two different domains simultaneously, would that cause any problem?
 
Both xend and xm commands use python, so are they multi-thread-safe?
 
Please let me know, 
 
Thanks,
Amitabh

		
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Re: [Xen-devel] IMPORTANT: Mailing list closed

[Adam H. <do...@br...>]

On Mon, 28 Mar 2005, James Bulpin wrote:

> The xen-devel mailing list hosted by SourceForge is now closed. If you
> have not already done so, please visit http://lists.xensource.com/ and
> subscribe to the new lists.
>
> From now on please use xen...@li... for Xen development
> topics and xen...@li... for discussion of the
> installation and use of Xen and its supported operatings systems.

Very very poor.

You gave no warning, and no backwards compatibility.  Not even forwarding the
new list to the old list.  You could have at least auto-subscribed everyone to
the new list.

Re: [Xen-devel] hanging dell hardware

[michal u. <mi...@an...>]

On Thu, Mar 24, 2005 at 09:45:51PM -0000, Ian Pratt wrote:
>  > It hangs, solid. No ssh, dead to the network, console dead, etc. No
> > reboot... I've come back to a hung machine after a weekend, and it was
> > still hung. 
> > 
> > Once it hangs, I can't get anything on a console or anything. Nothing
> > makes it down to the logs, either, as far as I can tell.
> 
> Please can you switch to a text console and then try an get it to hang.
> Hopefully something will come out. 
> 
> Also, please can you add 'watchdog' to the Xen command line in
> grub.conf.
>  
> > The machine is a PowerEdge 2850, the controller is a PERC 4e/Di.
> 
> Is this the standard on-board SCSI controller?
> 
> Ian

Sorry the response took so long...

anyway, it looks like it's a xen problem. I booted the machine with a
2.6.10 non-xen kernel, and had it doing heavy io for the past three
days... it stayed up.

On a text console, when it hangs I get nothing. I've added watchdog to
the relevant line in grub.conf, and that doesn't seem to do anything (it
does seem like it takes longer for it to crash, but that's probably my
imagination :)

I'm waiting for it to hang while I'm tail -f'ing various things in
/var/log... is kern.log the one I should be looking at?

The drive controller isn't the onboard one, it's an optional
dual-channel RAID controller.

-michal

[Xen-devel] [PATCH] make SMP boot again with gcc 4

[Rik v. R. <ri...@re...>]

For unknown reasons, this bug doesn't show up when Xen is compiled
with gcc-3.4, so I was off on a wild goose chase for a few days.
With this barrier added, the system boots fine again.

Note that we should probably move barrier into cpu_relax, but that's
a story for another patch.

Signed-off-by: Rik van Riel <ri...@re...>

--- xen-unstable/xen/arch/x86/smpboot.c.barrier	2005-03-28 15:17:11.000000000 -0500
+++ xen-unstable/xen/arch/x86/smpboot.c	2005-03-28 15:32:30.000000000 -0500
@@ -413,8 +413,10 @@ void __init start_secondary(void)
 
     smp_callin();
 
-    while (!atomic_read(&smp_commenced))
-        rep_nop();
+    while (!atomic_read(&smp_commenced)) {
+        cpu_relax();
+        barrier();
+    }
 
 #ifdef __i386__
     /*

Re: [Xen-devel] [bug?] xm sysrq == Internal Server Error

[Mark W. <ma...@cl...>]

> Using stable (2.05) tools and kernel, dom0 is CentOS 4.
>
> # xm sysrq mydomain s
> Error: Internal Server Error

Is this fixed for you yet?  Searching my mail archives, I don't see evidence 
for / against it having been dealt with.

If not, let me know - at first glance, it doesn't look like a difficult fix.

Cheers,
Mark

> (sorry for the word-wrapping)
> ==> /var/log/xend-debug.log <==
> {'key': 115}
> Traceback (most recent call last):
>   File "/usr/lib/python2.3/site-packages/twisted/protocols/basic.py", line
> 229, in dataReceived
>     return self.rawDataReceived(data)
>   File "/usr/lib/python2.3/site-packages/twisted/protocols/http.py", line
> 1015, in rawDataReceived
>     self.allContentReceived()
>   File "/usr/lib/python2.3/site-packages/twisted/protocols/http.py", line
> 1006, in allContentReceived
>     req.requestReceived(command, path, version)
>   File "/usr/lib/python2.3/site-packages/twisted/protocols/http.py", line
> 557, in requestReceived
>     self.process()
> --- <exception caught here> ---
>   File "/usr/lib/python2.3/site-packages/twisted/web/server.py", line 165,
> in process self.render(resrc)
>   File "/usr/lib/python2.3/site-packages/twisted/web/server.py", line 172,
> in render body = resrc.render(self)
>   File "/usr/lib/python2.3/site-packages/twisted/web/resource.py", line
> 201, in render
>     return m(request)
>   File "/usr/lib/python/xen/xend/server/SrvDomain.py", line 197, in
> render_POST return self.perform(req)
>   File "/usr/lib/python/xen/xend/server/SrvBase.py", line 103, in perform
>     return self._perform(op, op_method, req)
>   File "/usr/lib/python/xen/xend/server/SrvBase.py", line 109, in _perform
>     return self._perform_err(err, op, req)
>   File "/usr/lib/python/xen/xend/server/SrvBase.py", line 107, in _perform
>     val = op_method(op, req)
>   File "/usr/lib/python/xen/xend/server/SrvDomain.py", line 52, in
> op_shutdown val = fn(req.args, {'dom': self.dom.id})
>   File "/usr/lib/python/xen/xend/Args.py", line 140, in __call__
>     return self.call_with_form_args(self.fn, fargs, xargs=xargs)
>   File "/usr/lib/python/xen/xend/Args.py", line 116, in call_with_form_args
>     return fn(*params, **keys)
>   File "/usr/lib/python/xen/xend/XendDomain.py", line 477, in
> domain_shutdown val = xend.domain_shutdown(dominfo.id, reason, key)
>   File "/usr/lib/python/xen/xend/server/SrvDaemon.py", line 724, in
> domain_shutdown ctrl.shutdown(reason, key)
>   File "/usr/lib/python/xen/xend/server/domain.py", line 52, in shutdown
>     self.writeRequest(packMsg(msgtype, extra))
>   File "/usr/lib/python/xen/xend/server/messages.py", line 274, in packMsg
>     msg = xu.message(major, minor, msgid, args)
> exceptions.TypeError: payload contains bad items
>
> -Chris
>
>
>
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Re: [Xen-devel] RFC: 32 bits as smallest atomic size.

[Ronald G. M. <rmi...@la...>]

On Sun, 27 Mar 2005, Keir Fraser wrote:

> Already the field offset comments are broken in a few places in unstable, so
> perhaps this is a better way to go.

it's an idea.  A few years ago I wrote drivers for SCI and had a mixed 
linux/alpha freebsd/pentium cluster. It's a little tricky to get everyone 
happily addressing each other's memories across that boundary, but I did 
it by making all struct fields unsigned long long and letting the 
compilers do the right thing. I didn't use a single __attribute__ 
directive, but at the same time, these fairly different machines with 
different OSes had shared memory. I still don't see why xen can not do the 
same.

ron

Re: [Xen-devel] RFC: 32 bits as smallest atomic size.

[Ronald G. M. <rmi...@la...>]

On Sun, 27 Mar 2005, Keir Fraser wrote:

> 
> On 27 Mar 2005, at 04:34, Ronald G. Minnich wrote:
> 
> > My issues with the Plan 9 port have all revolved around portability from
> > x86 to x86, due to the gcc-isms in the headers.
> 
> I don't think there are that many gcc-isms, apart from use of PACKED (please
> correct me if I'm wrong). 

that's the biggie. And I don't see the need in many cases. 

> You can always define that to nothing if you need to
> - I'd hope that no compiler adds padding since all fields should be naturally
> aligned. 

They are not in all cases. 

I will try to find a simple example later today. 

thanks

ron

[Xen-devel] IMPORTANT: Mailing list closed

[James B. <ja...@xe...>]

The xen-devel mailing list hosted by SourceForge is now closed. If you
have not already done so, please visit http://lists.xensource.com/ and
subscribe to the new lists.

From now on please use xen...@li... for Xen development
topics and xen...@li... for discussion of the
installation and use of Xen and its supported operatings systems.

Regards,

James Bulpin

[Xen-devel] Re: poor domU VBD performance.

[peter b. <pet...@we...>]

Ian Pratt <m+Ian.Pratt <at> cl.cam.ac.uk> writes:

> 
> > I found out that dom0 does file-system IO and raw IO ( using 
> > dd as a tool to test
> > throughput from the disk ) is about exactly the same as when 
> > using a standard 
> > linux kernel without XEN. But the raw IO from DomU to an 
> > unused disk ( a second
> > disk in the system ) is limited to fourty percent of the 
> > speed I get within Dom0.
> 
> Just to be clear: you're doing a dd performance test within dom0 to the
> exact same partition on the 2nd disk that you're using when you start
> the domU and finding that the domU 'dd' performance is 40% of the dom0
> performance?
> 
> I've not heard of anyone else having problems like this. What happens if
> you use a partition on the 1st disk?
> 
> What chipset is the IDE controller? What device (e.g. sda1) are you
> exporting the disk partition into the domU as?
> 
> Are you sure dom 0 is idle when doing the dd test in the domU?
> 
> Ian
> 
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT Products from real users.
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> 

Yes, I have tried various partitions both from Dom0 and DomU on both disks and
the result has always been a performance ratio of 2.5 between Dom0 and DomU. 
Yes I used dd for the test. But I came accross this problem doing IO into 
the filesystem. I was surprised that I did not only get no improvement when
switching for a loopbacked file as "device" for DomU to a real device but that
I got a performance degradation. 
With that effect I started to test raw io performance using dd.

I am sure that the device was not busy and dom0 was idle when I did the test. 
There where no busy jobs in dom0 neither CPU- nor IO-bound. I don't know
which chipset the ide-controller is. My mainbord is a MSI KT7 board. I am
currently not at home, must lookup what the ide-controller is. 

The devices I exported to have been hda1 and hdb6 on my computer at home and
hdg5 in the office. In the latter case the disk is attached to a Promise202
raid controller. 

Is there any description what I have to do to configure my system adequately 
to run efficiently using Xen ? If such where available I might be able to 
locate the problem myself.

I have not yet done a "dd performance" test using loopbacked files as devices
yet. I only used them as filesystems. 

Thanks in advance 
          Peter Bier 

Re: [Xen-devel] [history] VMM Quadrants

[<ma...@tw...>]

On Fri, Mar 04, 2005 at 03:01:01PM -0500, Rich Persaud wrote:
> Denali, VMware, User-Mode Linux (is Fig. 3 correct? where would Xen go?)
> 
>   http://www.eecs.umich.edu/techreports/cse/2002/CSE-TR-465-02.pdf

I don't remember seeing any answer to this (which may say more about my
memory than what actually happened), but since I was browsing through
the spool, looking for seed material for wiki pages, I was just looking
at this.  I may be wrong, but I'd guess that Xen 1.2 would go about
halfway between VM/370 and Denali (like both it directly and solely
controlled the hardware, but it supported more of the real architecture
for its guests than Denali, eg., virtual memory).  Given only two
dimensions, I suppose Xen 2 has drifted somewhat to the left, as it has
offloaded most of the hardware management onto dom0.  Perhaps it would
be more accurate to add a third dimension and place X2.0 out of the
plane of the graph (to represent the fact that the hardware-managing
host is actually one of its virtual machines - a rather level-confusing
approach) as well as about as far right as VMware.  Xen-unstable is
confusing things even more, probably.

(I'd forgotten about your followup with the longer list of papers.  Is
that available on the web somewhere that I could link to?)

-- 
Allen Funt was one of the great psychologists of the twentieth century.
His informal experiments and demonstrations on "Candid Camera"
showed us as much about human psychology and its surprising limitations
as the work of any academic psychologist.  -- Daniel Dennett

RE: [Xen-devel] Xen 2.05 - using printer (/dev/lp0) from a guest linux OS?

[Ian P. <m+I...@cl...>]

> No, it's an old parallel port printer... I was hoping for a way to
> export /dev/lp0 to the guest, but it doesn't sound like there's a way.

Xen (the unstable.bk version) has the capability to expose individual
ISA devices to guests. However, the control tools haven't caught up with
this yet.

You can do it in a hacky way for the moment though, by giving the domU
full IO privilege. If you do this, you'll have to be careful to ensure
that only one domain has a driver for the parallel port, otherwise bad
things will happen if they both try to access it.

Ian=20
=20
> I wanted to set up a print server in a guest OS, then move=20
> the guest OS
> setup to a bootable CD and have a stateless print server... xen would
> make this a little easier since reboots are faster... using=20
> lpr might be
> close enough for testing.

RE: [Xen-devel] Xen 2.05 - using printer (/dev/lp0) from a guest linux OS?

[<u-b...@co...>]

No, it's an old parallel port printer... I was hoping for a way to
export /dev/lp0 to the guest, but it doesn't sound like there's a way.

I wanted to set up a print server in a guest OS, then move the guest OS
setup to a bootable CD and have a stateless print server... xen would
make this a little easier since reboots are faster... using lpr might be
close enough for testing.

On Sun, 27 Mar 2005 21:07:48 +0100, "Ian Pratt"
<m+I...@cl...> said:
> > Is there any way for the guest OS to use the printer?
> 
> If it's a USB printer, you could try exporting it (exclusively) to the
> guest using the new USB virtualization stuff.
> 
> If you want to share the printer between domains, use CUPS, LPRng or
> Samba as you would for sharing a printer between physical machines.
> 
> Ian
> 
> > Right now, my debian guest OS (using the xen linux 2.6 unpriv kernel)
> > can't see the printer at all.
> > 
> > My dom0 OS is ubuntu, based on debian.
> > 
> > Thanks.
> > 
> > 
> > -------------------------------------------------------
> > SF email is sponsored by - The IT Product Guide
> > Read honest & candid reviews on hundreds of IT Products from 
> > real users.
> > Discover which products truly live up to the hype. Start reading now.
> > http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> > _______________________________________________
> > Xen-devel mailing list
> > Xen...@li...
> > https://lists.sourceforge.net/lists/listinfo/xen-devel
> > 

RE: [Xen-devel] Xen 2.05 - using printer (/dev/lp0) from a guest linux OS?

[Ian P. <m+I...@cl...>]

> Is there any way for the guest OS to use the printer?

If it's a USB printer, you could try exporting it (exclusively) to the
guest using the new USB virtualization stuff.

If you want to share the printer between domains, use CUPS, LPRng or
Samba as you would for sharing a printer between physical machines.

Ian

> Right now, my debian guest OS (using the xen linux 2.6 unpriv kernel)
> can't see the printer at all.
>=20
> My dom0 OS is ubuntu, based on debian.
>=20
> Thanks.
>=20
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>=20

[Xen-devel] Xen 2.05 - using printer (/dev/lp0) from a guest linux OS?

[<u-b...@co...>]

Is there any way for the guest OS to use the printer?

Right now, my debian guest OS (using the xen linux 2.6 unpriv kernel)
can't see the printer at all.

My dom0 OS is ubuntu, based on debian.

Thanks.

RE: [Xen-devel] Interim Xen Wiki [was: domU Filesystems]

[Ian P. <m+I...@cl...>]

> On Fri, Mar 25, 2005 at 03:35:47PM -0600, Anthony Liguori wrote:
> > Here are the mechanisms I know and their requirements.  I=20
> plan to put=20
> > this in the Wiki as soon as it goes live (if it's not=20
> already there):
>=20
> Last "Real Soon Now" I saw was back ont he 10th, and that was an
> important reason I didn't do this sooner.  As of ten minutes ago, a
> nearly empty Interim Xen Wiki is up and running at

Guys, be patient!

We've had a wiki in place on wiki.xensource.com for some time, but we've
been too busy too pre-load it with all the content that we wanted to. A
few people have been working away adding stuff, but its my experience
that wiki's work much better if you get the site structure right before
having everyone pile in.=20

Anyhow, wiki.xensource.com is up and running. If there's any volunteers
to help get the site layout right, please get in touch.

Thanks,
Ian

Re: [Xen-devel] xend unable to start: xen.lowlevel.xu.PortError

[Keir F. <Kei...@cl...>]

On 26 Mar 2005, at 16:14, Erik de Bruijn - BudgetDedicated.com wrote:

> Where can we look to fix this problem without having to reboot, and
> without encountering the same problem again? Browsing the source-code
> didn't give me any pointers yet. Please tell me if more information
> would be helpful and what info that would be.

I think xend xometimes gets confused by its own state files that get 
left around after it is killed. You might want to try blowing away 
/var/lib/xen, and mkdir a fresh one.

  -- Keir

RE: [Xen-devel] poor domU VBD performance.

[Ian P. <m+I...@cl...>]

> I found out that dom0 does file-system IO and raw IO ( using=20
> dd as a tool to test
> throughput from the disk ) is about exactly the same as when=20
> using a standard=20
> linux kernel without XEN. But the raw IO from DomU to an=20
> unused disk ( a second
> disk in the system ) is limited to fourty percent of the=20
> speed I get within Dom0.

Just to be clear: you're doing a dd performance test within dom0 to the
exact same partition on the 2nd disk that you're using when you start
the domU and finding that the domU 'dd' performance is 40% of the dom0
performance?

I've not heard of anyone else having problems like this. What happens if
you use a partition on the 1st disk?

What chipset is the IDE controller? What device (e.g. sda1) are you
exporting the disk partition into the domU as?

Are you sure dom 0 is idle when doing the dd test in the domU?

Ian

Re: [Xen-devel] RFC: 32 bits as smallest atomic size.

[David H. <dav...@bl...>]

Keir Fraser wrote:
> On 27 Mar 2005, at 00:27, David Hopwood wrote:
>> Keir Fraser wrote:
>>> On 26 Mar 2005, at 17:31, Jimi Xenidis wrote:
>>>
>>>>>> Few things to note:
>>>>>> 1) packed is [un]necessary since the ABI will do the right thing
>>>
>>> I prefer to pack things explicitly rather than rely on ABI padding.
>>
>> If you use -Wpadded when compiling with gcc then you're not relying on
>> ABI padding; you're automatically checking that it is not used. That
>> would seem to be precisely what is required here.
> 
> If I could specify it on a per-struct basis then it would be perfect.

There is no way to selectively enable/disable warnings in gcc:
<http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9049>  :-(

OTOH, spurious warnings for padding in private structures cause no real
harm. If only a few private structures are involved, you could add dummy
padding to those anyway.

-- 
David Hopwood <dav...@bl...>

[Xen-devel] rebooting domU

[Brian H. <bri...@gm...>]

Hello,

What is the best way to reboot domU's? In my domU config file I have
set "restart = 'always'" but when executing the reboot command from
within a domU I can see it shutting down, then output that says
"Restarting system.", but then it just hangs there. It doesn't seem to
start back up again. Upon executing "xm list" within dom0 my domU
shows a status of 's' (shutdown). Any ideas on this?

Thanks,
Brian Hays

[Xen-devel] problem w/ mbootpack

[Roee S. <ro...@vo...>]

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IA0KdGhhbmtzLA0KIA0KUm8nZWUNCg==

Re: [Xen-devel] RFC: 32 bits as smallest atomic size.

[Keir F. <Kei...@cl...>]

On 27 Mar 2005, at 11:56, Keir Fraser wrote:

> I don't think there are that many gcc-isms, apart from use of PACKED 
> (please correct me if I'm wrong). You can always define that to 
> nothing if you need to - I'd hope that no compiler adds padding since 
> all fields should be naturally aligned. I don't see us moving to a 
> model where we define macros on char arrays anytime soon. :-) But 
> perhaps we could include a script to generate such macros from our 
> structure definitions....

Actually this would get round the need to manually determine field 
offsets -- we could get rid of PACKED, let fields fall as they may, and 
then run the headers through gcc to get field offsets for those who 
need them. There are a very few cases where we actually really care 
about two fields being directly adjacent, but I could add annotations 
in the header files and run a script to check that the placement 
constraints are satisfied.

Already the field offset comments are broken in a few places in 
unstable, so perhaps this is a better way to go.

  -- Keir