For (b) we can simply use 'dd' and 'ssh'. The general plan is to do
this:
- dd if=/dev/disk | gzip | ssh xenhost 'cat > /var/lib/xen/images/disk.img'
+ dd if=/dev/disk | gzip | ssh xenhost 'zcat > /var/lib/xen/images/disk.img'
If the user doesn't have sshd installed on the Xen host, then they can
also opt for a pure TCP transport:
dd if=/dev/disk | gzip | nc xenhost port
and on the remote host they do:
- nc -l -p port > /var/lib/xen/images/disk.img
+ nc -kl port > /var/lib/xen/images/disks
For (c) we can use device-mapper snapshots to mount a ramdisk above
the disks themselves. This allows us to make non-destructive changes