iSCSI as PV for KVM Host LVM

Direct connetion as pool

<pool type='iscsi'>
    <name>iscsi1</name>
    <source>
        <host name='192.168.1.10'/>
        <device path='iqn.xxxxx'/>
    </source>
    <target>
        <path>/dev/disk/by-path</path>
    </target>
</pool>

I prefer iSCSI as backing storage for LVM

iSCSI target attached as /dev/sdc on KVM Host
partitioning /dev/sdc

# fdisk -l /dev/sdc
  ...
   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1            2048     4194303     2096128   8e  Linux LVM

Virt-manager GUI:
- Host → Details → Storage → Add pool
  - Step1: Name=iscsi1, Type=logical:LVM Volume Group
  - Step2: Target Path=/dev/iscsi1vg, Source Path=(NO /dev/sdc1, better by-path)'/dev/disk/by-path/iqnxxx', Build Pool: flagged → Finish
- Select iscsi1 in left pane then NewVolume: Name=tubu1b
- VM(tubu1) → Open → Details → Add Hardware → Storage
  - Allocate entire disk now= flagged
  - Select managed or..
  - Browse to volume tubu1b: /dev/iscsi1vg/tubu1b
  - Device type= Virtio disk
  - Cache mode= default
  - Storage format: leave blank
  - Finish
Check KVM Host

# pvdisplay -m
  --- Physical volume ---
  PV Name               /dev/sdc1
  VG Name               iscsi1vg
  PV Size               2.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              511
  Free PE               0
  Allocated PE          511
  ...
  --- Physical Segments ---
  Physical extent 0 to 510:
    Logical volume	/dev/iscsi1vg/tubu1b
    Logical extents	0 to 510
  ...

On Guest tubu1 format and mount new disk

# fdisk -l /dev/vdb
Disk /dev/vdb: 2143 MB, 2143289344 bytes
...
   Device Boot      Start         End      Blocks   Id  System
/dev/vdb1            2048     4186111     2092032   83  Linux

# mkfs.ext4 /dev/vdb1
# mount /dev/vdb1 /media/test

Check copy with cluster failover

Trig a cluster failover (crm node standby node1) during copy1, VM freeze for 2 seconds

# pv ubuntu-12.04-server-amd64.iso > /media/test/ubuntu.iso

Trig a second cluster failover (crm node standby node2) during copy2, VM freeze for 2 seconds

# pv ubuntu-12.04-server-amd64.iso > /media/test/ubuntu1.iso

Verify data integrity

diff /media/test/ubuntu.iso /media/test/ubuntu1.iso

NOTE: a bug http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=663931 then you need /etc/init.d/udev restart on KVM host if virt-manager timeout

VM clone ⇒

⇐ Main LVM configuration

⇑ Hypervisor