converting to bcache on bs04 using "blocks" util in a saucy chroot
 - this ultimately didnt work - see further below for actual procedure used.

wiki this on jabawok.net/wiki

somewhat following: https://help.ubuntu.com/community/BasicChroot
apt-get install debootstrap and schroot

sudo mkdir -p /var/chroot/saucy

sudo debootstrap --variant=buildd --arch amd64 saucy /var/chroot/saucy/ http://old-releases.ubuntu.com/releases/

copy resolv.conf and bind mount proc and dev and sys

chroot in as root

===inside chroot===
added restricted universe multiverse to sources.list  and apt-get update
apt-get install vim
apt-get install python3.3 python3-pip git libparted-dev libaugeas0  pkg-config libpython3.3-dev gcc
apt-get install cryptsetup lvm2 liblzo2-dev nilfs-tools reiserfsprogs xfsprogs e2fsprogs btrfs-tools
apt-get install software-properties-common
add-apt-repository ppa:g2p/storage
apt-get update
apt-get install wget
apt-get install bcache-tools

pip-3.3 install --user -r <(wget -O- https://raw.github.com/g2p/blocks/master/requirements.txt)

 #blocks will be at ~/.local/bin/blocks

BLOCKS didnt work with NTFS contained filesystem - (it needs to check filesys for space etc.. go figure)

====================== Manual bcache conversion with lvm ===============

<code>
lvdisplay -m  >save.this.for.later.sanity.check
make a 1 extent lv for the bcache superblock
make-bcache -B -o 8192 /dev/sanvg/bcache-header
lvchange -a n /dev/sanvg/bcache-header
lvchange -a n /dev/sanvg/(target)
vgcfgbackup -f old.lvm.backup sanvg
cp old.lvm.backup new.lvm.backup
 # edit the new file, 
	increase segment size of target, 
	cut/paste the segment from bcache-header to the start of the target lv
	increment the segment header block numbers
	increment the logical start position of remaining segments
vgcfgrestore -f new.lvm.backup sanvg

 #sanity check with lvdisplay -m, compare to prev 
</code>