Create a cluster with at least two nodes.

Configure your cluster to run dlm, clvmd, and STONITH:

root # crm configure
crm(live)configure# primitive clvmd ocf:lvm2:clvmd \
        op stop interval="0" timeout="100" \
        op start interval="0" timeout="90" \
        op monitor interval="20" timeout="20"
crm(live)configure# primitive dlm ocf:pacemaker:controld \
        op start interval="0" timeout="90" \
        op stop interval="0" timeout="100" \
        op monitor interval="60" timeout="60"
crm(live)configure# primitive sbd_stonith stonith:external/sbd
crm(live)configure# group base-group dlm clvmd
crm(live)configure# clone base-clone base-group \
        meta interleave="true"

Leave crmsh with exit and commit your changes.

Create a clustered volume group (VG):

root # pvcreate /dev/sda /dev/sdb
root # vgcreate -cy vg /dev/sda /dev/sdb

Create a mirrored-log logical volume (LV) in your cluster:

root # lvcreate -nlv -m1 -l10%VG vg --mirrorlog mirrored

Use lvs to show the progress. If the percentage number has reached 100%, the mirrored disk is successfully synced.

To test the clustered volume /dev/vg/lv, use the following steps:

1. Read or write to /dev/vg/lv.

2. Deactivate your LV with lvchange -an.

3. Activate your LV with lvchange -ay.

4. Use lvconvert to convert a mirrored log to a disk log.

Create a mirrored-log LV in another cluster VG. This is a different volume group from the previous one.

Create a volume group (VG):

root # pvcreate /dev/sda /dev/sdb
root # vgcreate vg /dev/sda /dev/sdb

Open the file /etc/lvm/lvm.conf and go to the section allocation. Set the following line and save the file:

mirror_legs_require_separate_pvs = 1

Add your tags to your PVs:

root # pvchange --addtag @a /dev/sda
root # pvchange --addtag @b /dev/sdb

A tag is an unordered keyword or term assigned to the metadata of a storage object. Tagging allows you to classify collections of LVM storage objects in ways that you find useful by attaching an unordered list of tags to their metadata.

List your tags:

root # pvs -o pv_name,vg_name,pv_tags /dev/sd{a,b}

You should receive this output:

  PV         VG     PV Tags
  /dev/sda vgtest a
  /dev/sdb vgtest b

Start a shell and log in as root.

Run crm configure.

Check the current configuration of the cluster resources with show.

If you have already configured a DLM resource (and a corresponding base group and base clone), continue with Procedure 16.2, “Creating LVM and cLVM Resources”.

Otherwise, configure a DLM resource and a corresponding base group and base clone as described in Procedure 13.2, “Configuring a DLM Resource”.

Leave the crm live configuration with exit.

Start a shell and log in as root.

Run crm configure.

Configure a cLVM resource as follows:

crm(live)configure# primitive clvm ocf:lvm2:clvmd \
      params daemon_timeout="30"

Configure an LVM resource for the volume group as follows:

crm(live)configure# primitive vg1 ocf:heartbeat:LVM \
      params volgrpname="cluster-vg" \
      op monitor interval="60" timeout="60"

If you want the volume group to be activated exclusively on one node, configure the LVM resource as described below and omit Step 6:

crm(live)configure# primitive vg1 ocf:heartbeat:LVM \
      params volgrpname="cluster-vg" exclusive="yes" \
      op monitor interval="60" timeout="60"

In this case, cLVM will protect all logical volumes within the VG from being activated on multiple nodes, as an additional measure of protection for non-clustered applications.

To ensure that the cLVM and LVM resources are activated cluster-wide, add both primitives to the base group you have created in Procedure 13.2, “Configuring a DLM Resource”:

1. Enter

   crm(live)configure# edit base-group

2. In the vi editor that opens, modify the group as follows and save your changes:

   crm(live)configure# group base-group dlm clvm vg1 ocfs2-1

   

   Important: Setup Without OCFS2

   If your setup does not include OCFS2, omit the ocfs2-1 primitive from the base group.

Review your changes with show.

If everything is correct, submit your changes with commit and leave the crm live configuration with exit.

Run YaST and click Network Services › iSCSI Target to start the iSCSI Server module.

If you want to start the iSCSI target whenever your computer is booted, choose When Booting, otherwise choose Manually.

If you have a firewall running, enable Open Port in Firewall.

Switch to the Global tab. If you need authentication enable incoming or outgoing authentication or both. In this example, we select No Authentication.

Add a new iSCSI target:

1. Switch to the Targets tab.

2. Click Add.

3. Enter a target name. The name has to be formatted like this:

   iqn.DATE.DOMAIN

   For more information about the format, refer to , Section 3.2.6.3.1. Type "iqn." (iSCSI Qualified Name) (http://www.ietf.org/rfc/rfc3720.txt).

4. If you want a more descriptive name, you can change it as long as your identifier is unique for your different targets.

5. Click Add.

6. Enter the device name in Path and use a Scsiid.

7. Click Next twice.

Confirm the warning box with Yes.

Open the configuration file /etc/iscsi/iscsi.conf and change the parameter node.startup to automatic.

Run YaST and click Network Services › iSCSI Initiator.

If you want to start the iSCSI initiator whenever your computer is booted, choose When Booting, otherwise set Manually.

Change to the Discovery tab and click the Discovery button.

Add your IP address and your port of your iSCSI target (see Procedure 16.3, “Configuring iSCSI Targets (SAN)”). Normally, you can leave the port as it is and use the default value.

If you use authentication, insert the incoming and outgoing username and password, otherwise activate No Authentication.

Select Next. The found connections are displayed in the list.

Proceed with Finish.

Open a shell, log in as root.

Test if the iSCSI initiator has been started successfully:

root # iscsiadm -m discovery -t st -p 192.168.3.100
192.168.3.100:3260,1 iqn.2010-03.de.jupiter:san1

Establish a session:

root # iscsiadm -m node -l
Logging in to [iface: default, target: iqn.2010-03.de.jupiter:san2, portal: 192.168.3.100,3260]
Logging in to [iface: default, target: iqn.2010-03.de.venus:san1, portal: 192.168.3.101,3260]
Login to [iface: default, target: iqn.2010-03.de.jupiter:san2, portal: 192.168.3.100,3260]: successful
Login to [iface: default, target: iqn.2010-03.de.venus:san1, portal: 192.168.3.101,3260]: successful

See the device names with lsscsi:

...
[4:0:0:2]    disk    IET      ...     0     /dev/sdd
[5:0:0:1]    disk    IET      ...     0     /dev/sde

Look for entries with IET in their third column. In this case, the devices are /dev/sdd and /dev/sde.

Open a root shell on one of the nodes you have run the iSCSI initiator from Procedure 16.4, “Configuring iSCSI Initiators”.

Prepare the physical volume for LVM with the command pvcreate on the disks /dev/sdd and /dev/sde:

root # pvcreate /dev/sdd
root # pvcreate /dev/sde

Create the cluster-aware volume group on both disks:

root # vgcreate --clustered y clustervg /dev/sdd /dev/sde

Create logical volumes as needed:

root # lvcreate --name clusterlv --size 500M clustervg

Check the physical volume with pvdisplay:

  --- Physical volume ---
      PV Name               /dev/sdd
      VG Name               clustervg
      PV Size               509,88 MB / not usable 1,88 MB
      Allocatable           yes
      PE Size (KByte)       4096
      Total PE              127
      Free PE               127
      Allocated PE          0
      PV UUID               52okH4-nv3z-2AUL-GhAN-8DAZ-GMtU-Xrn9Kh
      
      --- Physical volume ---
      PV Name               /dev/sde
      VG Name               clustervg
      PV Size               509,84 MB / not usable 1,84 MB
      Allocatable           yes
      PE Size (KByte)       4096
      Total PE              127
      Free PE               127
      Allocated PE          0
      PV UUID               Ouj3Xm-AI58-lxB1-mWm2-xn51-agM2-0UuHFC

Check the volume group with vgdisplay:

  --- Volume group ---
      VG Name               clustervg
      System ID
      Format                lvm2
      Metadata Areas        2
      Metadata Sequence No  1
      VG Access             read/write
      VG Status             resizable
      Clustered             yes
      Shared                no
      MAX LV                0
      Cur LV                0
      Open LV               0
      Max PV                0
      Cur PV                2
      Act PV                2
      VG Size               1016,00 MB
      PE Size               4,00 MB
      Total PE              254
      Alloc PE / Size       0 / 0
      Free  PE / Size       254 / 1016,00 MB
      VG UUID               UCyWw8-2jqV-enuT-KH4d-NXQI-JhH3-J24anD

Create a primary/primary DRBD resource:

1. First, set up a DRBD device as primary/secondary as described in Procedure 15.1, “Manually Configuring DRBD”. Make sure the disk state is up-to-date on both nodes. Check this with cat /proc/drbd or with systemctl status drbd.service.

2. Add the following options to your configuration file (usually something like /etc/drbd.d/r0.res):

   resource r0 {
     startup {
       become-primary-on both;
     }
   
     net {
        allow-two-primaries;
     }
     ...
   }

3. Copy the changed configuration file to the other node, for example:

   root # scp /etc/drbd.d/r0.res venus:/etc/drbd.d/

4. Run the following commands on both nodes:

   root # drbdadm disconnect r0
   root # drbdadm connect r0
   root # drbdadm primary r0

5. Check the status of your nodes:

   root # cat /proc/drbd
   ...
    0: cs:Connected ro:Primary/Primary ds:UpToDate/UpToDate C r----

Include the clvmd resource as a clone in the pacemaker configuration, and make it depend on the DLM clone resource. See Procedure 16.1, “Creating a DLM Resource” for detailed instructions. Before proceeding, confirm that these resources have started successfully on your cluster. You may use crm_mon or the Web interface to check the running services.

Prepare the physical volume for LVM with the command pvcreate. For example, on the device /dev/drbd_r0 the command would look like this:

root # pvcreate /dev/drbd_r0

Create a cluster-aware volume group:

root # vgcreate --clustered y myclusterfs /dev/drbd_r0

Create logical volumes as needed. You may probably want to change the size of the logical volume. For example, create a 4 GB logical volume with the following command:

root # lvcreate --name testlv -L 4G myclusterfs

The logical volumes within the VG are now available as file system mounts or raw usage. Ensure that services using them have proper dependencies to collocate them with and order them after the VG has been activated.