On 02/25/2011 10:58 AM, Somebody in the thread at some point said:
On Thu, Feb 24, 2011, Mounir Bsaibes wrote:
Hi -
We have a need for a Panda and a Beagle to compare& fix performance. As I recall from last meeting, the Panda's USB I/O has 2x performance degradation from Beagle. Per or Mian may have more details on that.
Ok; interesting!
My initial fear was that the kernel testing might trigger unbootable boards and that it would be tricky to work with unstable kernels remotely; for USB performance testing, I can see that we could set it up for remote testing, but we need to have something plugged to USB and be careful to use the same hardware on both boards so that it compares usefully.
1&1 (webhosts) have an interesting approach to this for their unmanaged boxes, they have the same problem with people doing kernel or bootloader upgrades making their box unworkable.
You can ssh into a second "buddy" box who has a serial connection to the target box's serial port (in the 1&1 case they set grub even to issue serial menus). The buddy box also controls the target via a smart power switch.
When you cycle the target power using a web interface to the buddy box, you can also select to force a canned boot path sent over bootp, so even a trashed box with no bootloader can be recovered.
When you select a canned boot, you can use your ssh connection to the buddy box to see boot messages and login to the target, so it's an ssh <-> serial bridge basically.
They deploy this on all their unmanaged servers, they just have a few buddy boxes each handling many servers.
It's not far away from being workable on embedded boards, maybe by having an adapter card that sites two SD cards in one slot, you can enable the normal one or a backup read-only one based on a line controlled by its buddy box.
-Andy