btrfs using inside xen domU and online resizing

Hello. I have two questions:

1) When btrfs can be used in systems, that can be rebooted unexpectedly? btrfs fsck is ready to use? does after power failure or hard reboot file system can be damaged and can't be corrected?

2) When i use xen domU virtual machine a can dynamically change capacity of block device (/dev/xvda for example) it can be grows and shrinks. Is that possible to use one btrfs file system on all device without partition table ? In current implementation (i'm use ext3). After block device change it size, i need to recreate partition table and do resize2fs. But in case of root fs i need reboot to update partition table, because file system is in use. If linux can boot from plain btrfs device without partition table , as i think - i can resize block device and do mount -o remount,maxsize /dev/xvda and btrfs resized automatic...
Is that possible?

Thank You for all suggestions and answers.

tor 2011-01-06 klockan 04:10 +0300 skrev Vasiliy G Tolstov:

If you turn of the write-cache of the underlying disks, btrfs should survive it. I have btrfs on top of dm-crypt and no write-cache, and it has survived all crashes so far. But you never know, so I backupp regularly. Fsck is not ready yet.

Why not use LVM?
If you do not have a partition table (or only one partition) you can only have one file system on the disk, so why not use the entire disk in the first place?

// Maria