Re: device failure hangs the system

[Anand Jain <Anand.Jain@oracle.com>]

  Looks like there is a panic (not system hang).
  any idea where is the panic log after the system has been
  power-recycled. (its not in the /var/log/messages or dmesg or
  /var/crash is empty)

Thanks, Anand


On 07/01/2011 05:25 PM, Anand Jain wrote:
>
> hi,
>
> Following test case causes my remote system to hard-hang and does
> not respond to any key strokes.
>
> -----------
> # btrfs fi show
> failed to read /dev/sr0
> Label: none uuid: 75ad3c9f-f661-498e-8c13-89d4e4c58312
> Total devices 3 FS bytes used 28.00KB
> devid 1 size 465.76GB used 2.02GB path /dev/sdb
> devid 3 size 465.76GB used 2.01GB path /dev/sdd
> devid 2 size 465.76GB used 1.01GB path /dev/sdc
>
> Btrfs v0.19-35-g1b444cd
> ------------
>
>
> Stopping the disk
> ------------
> # echo 1 > /sys/block/sdd/device/delete
> ------------
> ------------
> # dmesg | tail
> sd 3:0:0:0: [sdd] Stopping disk
> ::
> #
> ------------
>
> ------------
> # btrfs fi show
> failed to read /dev/sr0
> Label: none uuid: 75ad3c9f-f661-498e-8c13-89d4e4c58312
> Total devices 3 FS bytes used 28.00KB
> devid 1 size 465.76GB used 2.02GB path /dev/sdb
> devid 2 size 465.76GB used 1.01GB path /dev/sdc
> *** Some devices missing
>
> Btrfs v0.19-35-g1b444cd
> ------------
>
> and the following command hangs the system.
> -------------
> # btrfs fi balance /btrfs
> -------------
>
> Any idea if this is an known issue ? OR if there is any better way
> to fail a disk (or a loop disk) for testing.
>
> (something similar to cfgadm -c unconfigure in solaris).
>
> Thanks
> -Anand
>