Subject: Re: xen and ccd
To: Martti Kuparinen <martti.kuparinen@iki.fi>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: port-xen
Date: 03/31/2005 19:49:19
On Thu, Mar 31, 2005 at 12:03:22PM +0300, Martti Kuparinen wrote:
> Hi again!
> 
> I'm running 3.99.2 (/usr/src updated and kernel rebuilt today).
> I have some space allocated for CCD on my harddisk:
> 
> # /dev/rwd0d:
> 16 partitions:
> #        size    offset     fstype [fsize bsize cpg/sgs]
>  a:   8192016        63     4.2BSD   2048 16384 27560
>  b:    263088   8192079       swap
>  c: 312499937        63     unused      0     0     0
>  d: 312500000         0     unused      0     0     0
>  e: 104857600   8455167     4.2BSD      0     0     0
>  f: 194992929 113312767        ccd
>  g:   4194304 308305696        ccd
> 
> 
> The configuration file for CCD looks like this:
> 
> ccd0            16      none    /dev/wd0f
> ccd1            16      none    /dev/wd0g
> 
> 
> I have created a disklabel for ccd0:
> 
> # /dev/rccd0d:
> 16 partitions:
> #        size    offset     fstype [fsize bsize cpg/sgs]
>  d: 194992928         0     unused      0     0
>  e:  20971520         0        ccd
>  f:  20971520  20971520        ccd
>  g:  20971520  41943040        ccd
>  h:  20971520  62914560        ccd
>  i:  20971520  83886080        ccd
>  j:  20971520 104857600        ccd
>  k:  20971520 125829120        ccd
>  l:  20971520 146800640        ccd
>  m:  27220768 167772160        ccd
> 
> 
> Here's the xen config file I'm using:
> 
> #kernel = "/xen/kernel/netbsd-XENU"
> kernel = "/xen/kernel/netbsd-INSTALL_XENU"
> memory = 128
> name = "netbsd1"
> cpu = -1
> disk = [ 'phy:/dev/cd0a,cd0a,r', 'phy:/dev/ccd0e,wd0d,w' ]
> root = "/dev/wd0d"
> 
> 
> If I now try to start this domU and inside it suspend the
> NetBSD installer and try to zero the disk I get an error:
> 
> # dmesg
> ...
> xbd: using irq 5
> xbd0 at hypervisor0: Xen Virtual Block Device 10240 MB
> xbd1 at hypervisor0: Xen Virtual Block Device 404 MB
> 
> # dd if=/dev/zero of=/dev/rxbd0d
> dd: /dev/rxbd0d: Input/output error
> 2+0 records in
> 1+0 records out
> 512 bytes transferred in 0.001 secs (512000 bytes/sec)
> 
> This appears in /var/log/messages. Nothing appears in
> xend.log or xend-debug.log:
> 
> Mar 31 13:52:54 n86 /netbsd: xbd IO domain 1: error 30

30 is EROFS

> 
> 
> And now the questions:
> 
> - am I doing something wrong with ccd?

You can't start a partition at offset 0. Othervise this will erase the
disklabel of the ccd.

> 
> - what type should I use for ccd0[e-m] if I want to use each
>   as a "harddisk" for domU?

it doens't really matters as long as the device can be open'ed (so I think
type "unused" would not work, but any other will).

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--