On Mon, 2015-07-27 at 12:36 +0200, Jens-U. Mozdzen wrote:

- bcache bucket size is 512k, tree_depth is 1

- setup details:

-- md RAID6 "data" via seven 1 TB physical disks ("blockdev --getsz"  
reports 9767605760 512byte blocks, approx 5 TB)

-- md RAID1 "cache" via two 128 GB SSDs ("blockdev --getsz" reports  
249936512 512byte blocks, approx 125 GB)

-- "bcache0" made from "data" and "cache"

-- LVM via single physical volume "bcache0"

-- many LVs create with older kernel

-- DRBD on top of each LV. This server is always primary, no  
"fail-over" to a different node!

-- file system (to be) created on the DRBD devices

I tried setup DRBD on 2 VMs(qemu-kvm), but couldn't reproduce it.

Could you write a script to show how you setup all
these(bcache/RAID/LVM/DRBD)?