Re: No block devices in domU

[Anthony Liguori <aliguori@us.ibm.com>]

Gabor HALASZ wrote:

> Hi!
>
> I tried to build a devel xen on x86_64 (xeon) on debian sarge; updated 
> with mercurial, and built with default kernel config. When booting 
> domU I can't see xen_blk: initialize... line on the console and I 
> havn't block devices in domU.

Ryan Harper and I are looking into this right now.

There's a race condition somewhere in the block front driver.  Xend is 
doing everything it's supposed to and the frontend appears to be being 
probed.

Regards,

Anthony Liguori

> The messages of domU
>
> ...
> RAMDISK driver initialized: 16 RAM disks of 32768K size 1024 blocksize
> Xen virtual console successfully installed as tty1
> Event-channel device installed.
> xen_net: Initialising virtual ethernet driver.
> md: md driver 0.90.1 MAX_MD_DEVS=256, MD_SB_DISKS=27
> NET: Registered protocol family 2
> ...
> # mount /proc/
> # cat /proc/devices
> Character devices:
>   1 mem
>   4 tty
>   5 /dev/tty
>   5 /dev/console
>   5 /dev/ptmx
>  10 misc
> 128 ptm
> 136 pts
> 203 cpu/cpuid
>
> Block devices:
>   1 ramdisk
>   9 md
> 254 mdp
>
> The view from dom0:
>
> xen:~# xm list
> Name                              ID Mem(MiB) VCPUs State  Time(s)
> Domain-0                           0      245     1 r-----  2100.4
> test                              10      256     1 -b----     0.5
> xen:~# xm block-list 10
> (2049 ((virtual-device 2049) (backend-id 0) (backend 
> /local/domain/0/backend/vbd/10/2049) (ring-ref 8) (event-channel 6)))
> (2050 ((virtual-device 2050) (backend-id 0) (backend 
> /local/domain/0/backend/vbd/10/2050) (ring-ref 9) (event-channel 7)))
> (2051 ((virtual-device 2051) (backend-id 0) (backend 
> /local/domain/0/backend/vbd/10/2051) (ring-ref 10) (event-channel 8)))
>
> The configuration:
>
> xen:~# cat /etc/xen/test
> builder         = 'linux'
> kernel          = "/boot/vmlinuz-2.6.12.6-xenU"
> ramdisk         = "/boot/ramdisk.ext2"
> memory          = 256
> name            = "test"
> nics            = 0
> on_poweroff     = 'destroy'
> on_reboot       = 'restart'
> on_crash        = 'restart'
> root            = "/dev/ram0 rw"
> vcpus           = 1
> extra           = "ramdisk=32768"
> disk            = [ 'phy:evms/ZorpRoot,sda1,w', 
> 'phy:evms/ZorpLog,sda2,w', 'phy:evms/ZorpSwap,sda3,w' ]
>
> What can I do?
>