Install the headers from the newly generated kernel package.
Download the source for the version of DRBD you’re using.

Build the module:

make KDIR=/usr/src/linux-source-2.6.32.46-xen
make install

The configuration files I used for DRBD:

[email protected]:/etc/drbd.d# cat res0.res 
resource r0 {
	protocol C;
	net {
		cram-hmac-alg sha1;
		shared-secret "FooFunFactory";
	}
	on cnc {
		device drbd0;
		disk      /dev/cnc/centos;
		address   172.16.1.15:7789;
		flexible-meta-disk /dev/cnc/centos-drbd;
	}
	on remote {
		device drbd0;
		disk      /dev/sysvg/instance13193-disk;
		address   172.16.1.99:7789;
		flexible-meta-disk /dev/sysvg/instance13193-disk-drbd;
	}
}
[email protected]:/etc/drbd.d# cat res1.res 
resource r1 {
    net {
        cram-hmac-alg    sha1;
        shared-secret    FooFunFactory2;
    }
	on cnc {
		device drbd1;
		disk      /dev/cnc/centos-swap;
		address   172.16.1.15:7790;
		flexible-meta-disk /dev/cnc/centos-swap-drbd;
	}
	on remote {
		device drbd1;
		disk      /dev/sysvg/instance13193-swap;
		address   172.16.1.99:7790;
		flexible-meta-disk /dev/sysvg/instance13193-swap-drbd;
	}
}

Create metadata:

[email protected]:/etc/drbd.d# drbdadm create-md r0
Writing meta data...
initializing activity log
NOT initialized bitmap
New drbd meta data block successfully created.
success
[email protected]:/etc/drbd.d# drbdadm create-md r1
Writing meta data...
initializing activity log
NOT initialized bitmap
New drbd meta data block successfully created.
success

Attach DRBD to real disk:

drbd attach r0
drbd attach r1

Make this the primary node:

[email protected]:/etc/drbd.d# cat /proc/drbd 
version: 8.3.9 (api:88/proto:86-95)
GIT-hash: 1c3b2f71137171c1236b497969734da43b5bec90 build by [email protected], 2011-10-10 00:49:36
 0: cs:WFConnection ro:Secondary/Unknown ds:Inconsistent/DUnknown C r----s
    ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:10485760
 1: cs:WFConnection ro:Secondary/Unknown ds:Inconsistent/DUnknown C r----s
    ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:2097152
[email protected]:/etc/drbd.d# drbdadm -- --overwrite-data-of-peer primary r0
[email protected]:/etc/drbd.d# drbdadm -- --overwrite-data-of-peer primary r1
[email protected]:/etc/drbd.d# cat /proc/drbd 
version: 8.3.9 (api:88/proto:86-95)
GIT-hash: 1c3b2f71137171c1236b497969734da43b5bec90 build by [email protected], 2011-10-10 00:49:36
 0: cs:WFConnection ro:Primary/Unknown ds:UpToDate/DUnknown C r----s
    ns:0 nr:0 dw:0 dr:200 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:10485760
 1: cs:WFConnection ro:Primary/Unknown ds:UpToDate/DUnknown C r----s
    ns:0 nr:0 dw:0 dr:200 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:2097152

Update the configuration:

drbdadm adjust r0
drbdadm adjust r1

Wait until the data is UpToDate on both sides.

Once it’s uptodate you do a live migration.