btrfs recovery - howto?

[ghaspias]

My xbian system, in an external usb hd, is in an unbootable state, and I think it is just a problem with btrfs. Since I have important work backed up in the system partition, a reinstall is not possible.
Usually, even if it is not bootable, I would have no problem pluging that disk in another linux system (or just boot xbian from sdcard) to recover the data. But when I connect that hd to either a laptop linux system (Fedora 21 live) or a fresh xbian running on RPi B+, both crash with kernel panics!

So, is it safe to try to recover this btrfs file system on a different (laptop) linux system? Does the different compression (I think I have lzo, but I'm not quite sure -- how to check it?) affect the prospect of normal recovery?

Thanks for any suggestion.