debian xen 4.1 and 3.8.x kernel (from experimental)

debian xen 4.1 and 3.8.x kernel (from experimental)

[James Harper]

I'm trying to get ceph working with decent performance (currently getting kb/second write performance!) and it seems that maybe the Debian wheezy kernel is just a bit too ancient.

The 3.8 kernel from experimental works on bare metal, but when booting as dom0 under the xen hypervisor it crashes.
 
I just figured out how to redirect xen output to my IPMI/BMC serial port and I see this:

(XEN) HVM: Hardware Assisted Paging (HAP) detected
(XEN) HVM: HAP page sizes: 4kB, 2MB
(XEN) Brought up 4 CPUs
(XEN) *** LOADING DOMAIN 0 ***
(XEN) elf_init: not an ELF binary

Does this mean that Debian is compiling the kernel incorrectly (in which case I'll file a bug), or is my Xen now too old to support it?

Thanks

James

Re: debian xen 4.1 and 3.8.x kernel (from experimental)

[James Harper]

> 
> I'm trying to get ceph working with decent performance (currently getting
> kb/second write performance!) and it seems that maybe the Debian wheezy
> kernel is just a bit too ancient.
> 
> The 3.8 kernel from experimental works on bare metal, but when booting as
> dom0 under the xen hypervisor it crashes.
> 

I grabbed the xen packages from debian experimental and that now works. I was hoping to keep using 4.1 to minimise the changes...

James

Re: debian xen 4.1 and 3.8.x kernel (from experimental)

[Bastian Blank]

On Sat, Apr 20, 2013 at 01:18:09AM +0000, James Harper wrote:
> I'm trying to get ceph working with decent performance (currently getting kb/second write performance!) and it seems that maybe the Debian wheezy kernel is just a bit too ancient.
> The 3.8 kernel from experimental works on bare metal, but when booting as dom0 under the xen hypervisor it crashes.

I can boot linux 3.8.5-1~experimental.1 on a xen 4.1.4-3.

> I just figured out how to redirect xen output to my IPMI/BMC serial port and I see this:
> (XEN) HVM: Hardware Assisted Paging (HAP) detected
> (XEN) HVM: HAP page sizes: 4kB, 2MB
> (XEN) Brought up 4 CPUs
> (XEN) *** LOADING DOMAIN 0 ***
> (XEN) elf_init: not an ELF binary
> Does this mean that Debian is compiling the kernel incorrectly (in which case I'll file a bug), or is my Xen now too old to support it?

This means your Xen is older then the version in Wheezy and lacks
support for XZ.

Bastian

-- 
You can't evaluate a man by logic alone.
		-- McCoy, "I, Mudd", stardate 4513.3

Re: debian xen 4.1 and 3.8.x kernel (from experimental)

[Jan Beulich]

>>> On 20.04.13 at 13:45, Bastian Blank <bastian@waldi.eu.org> wrote:
> On Sat, Apr 20, 2013 at 01:18:09AM +0000, James Harper wrote:
>> I just figured out how to redirect xen output to my IPMI/BMC serial port and 
> I see this:
>> (XEN) HVM: Hardware Assisted Paging (HAP) detected
>> (XEN) HVM: HAP page sizes: 4kB, 2MB
>> (XEN) Brought up 4 CPUs
>> (XEN) *** LOADING DOMAIN 0 ***
>> (XEN) elf_init: not an ELF binary
>> Does this mean that Debian is compiling the kernel incorrectly (in which 
> case I'll file a bug), or is my Xen now too old to support it?
> 
> This means your Xen is older then the version in Wheezy and lacks
> support for XZ.

Which is being added in 4.1.5 ...

Jan

Re: debian xen 4.1 and 3.8.x kernel (from experimental)

[Bastian Blank]

On Mon, Apr 22, 2013 at 08:17:09AM +0100, Jan Beulich wrote:
> > On Sat, Apr 20, 2013 at 01:18:09AM +0000, James Harper wrote:
> >> Does this mean that Debian is compiling the kernel incorrectly (in which 
> > case I'll file a bug), or is my Xen now too old to support it?
> > This means your Xen is older then the version in Wheezy and lacks
> > support for XZ.
> Which is being added in 4.1.5 ...

Nope, in case of Debian it got added in 4.1.3-7:

| xen (4.1.3-7) unstable; urgency=low
| 
|   * Add support for XZ compressed Linux kernels to hypervisor and userspace
|     based loaders, it is needed for any Linux kernels newer then Wheezy.
|     (closes: #695056)
| 
|  -- Bastian Blank <waldi@debian.org>  Tue, 11 Dec 2012 18:54:59 +0100

Bastian

-- 
Suffocating together ... would create heroic camaraderie.
		-- Khan Noonian Singh, "Space Seed", stardate 3142.8