# Conversion to Active/Active

## Requirements

The primary requirement for an Active/Active cluster is that the data required for your services is available, simultaneously, on both machines. Pacemaker makes no requirement on how this is achieved, you could use a SAN if you had one available, however since DRBD supports multiple Primaries, we can also use that.

The only hitch is that we need to use a cluster-aware filesystem. The one we used earlier with DRBD, ext4, is not one of those. Both OCFS2 and GFS2 are supported, however here we will use GFS2 which comes with &DISTRO; &DISTRO_VERSION; .

## Install a Cluster Filesystem - GFS2

The first thing to do is install gfs2-utils and gfs-pcmk on each machine. Since December 2010, the gfs-pcmk package in Fedora was replaced with the gfs2-cluster package and that will be installed automatically in place of the gfs-pcmk. If that package shows up on the line "installed" at the end of the yum output, please refer to the Appendix on "Using CMAN"

    [root@pcmk-1 ~]# yum install -y gfs2-utils gfs2-cluster gfs-pcmk
    Setting up Install Process
    Resolving Dependencies
    --> Running transaction check
    ---> Package gfs-pcmk.x86_64 0:3.0.5-2.fc12 set to be updated
    --> Processing Dependency: libSaCkpt.so.3(OPENAIS_CKPT_B.01.01)(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64
    --> Processing Dependency: dlm-pcmk for package: gfs-pcmk-3.0.5-2.fc12.x86_64
    --> Processing Dependency: libccs.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64
    --> Processing Dependency: libdlmcontrol.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64
    --> Processing Dependency: liblogthread.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64
    --> Processing Dependency: libSaCkpt.so.3()(64bit) for package: gfs-pcmk-3.0.5-2.fc12.x86_64
    ---> Package gfs2-utils.x86_64 0:3.0.5-2.fc12 set to be updated
    --> Running transaction check
    ---> Package clusterlib.x86_64 0:3.0.5-2.fc12 set to be updated
    ---> Package dlm-pcmk.x86_64 0:3.0.5-2.fc12 set to be updated
    ---> Package openaislib.x86_64 0:1.1.0-1.fc12 set to be updated
    --> Finished Dependency Resolution

    Dependencies Resolved

    ===========================================================================================
     Package                Arch               Version                   Repository        Size
    ===========================================================================================
    Installing:
     gfs-pcmk               x86_64             3.0.5-2.fc12              custom           101 k
     gfs2-utils             x86_64             3.0.5-2.fc12              custom           208 k
    Installing for dependencies:
     clusterlib             x86_64             3.0.5-2.fc12              custom            65 k
     dlm-pcmk               x86_64             3.0.5-2.fc12              custom            93 k
     openaislib             x86_64             1.1.0-1.fc12              fedora            76 k

    Transaction Summary
    ===========================================================================================
    Install       5 Package(s)
    Upgrade       0 Package(s)

    Total download size: 541 k
    Downloading Packages:
    (1/5): clusterlib-3.0.5-2.fc12.x86_64.rpm                                |  65 kB     00:00
    (2/5): dlm-pcmk-3.0.5-2.fc12.x86_64.rpm                                  |  93 kB     00:00
    (3/5): gfs-pcmk-3.0.5-2.fc12.x86_64.rpm                                  | 101 kB     00:00
    (4/5): gfs2-utils-3.0.5-2.fc12.x86_64.rpm                                | 208 kB     00:00
    (5/5): openaislib-1.1.0-1.fc12.x86_64.rpm                                |  76 kB     00:00
    -------------------------------------------------------------------------------------------
    Total                                                           992 kB/s | 541 kB     00:00
    Running rpm_check_debug
    Running Transaction Test
    Finished Transaction Test
    Transaction Test Succeeded
    Running Transaction
      Installing     : clusterlib-3.0.5-2.fc12.x86_64                                       1/5
      Installing     : openaislib-1.1.0-1.fc12.x86_64                                       2/5
      Installing     : dlm-pcmk-3.0.5-2.fc12.x86_64                                         3/5
      Installing     : gfs-pcmk-3.0.5-2.fc12.x86_64                                         4/5
      Installing     : gfs2-utils-3.0.5-2.fc12.x86_64                                       5/5

    Installed:
      gfs-pcmk.x86_64 0:3.0.5-2.fc12                    gfs2-utils.x86_64 0:3.0.5-2.fc12

    Dependency Installed:
      clusterlib.x86_64 0:3.0.5-2.fc12   dlm-pcmk.x86_64 0:3.0.5-2.fc12
      openaislib.x86_64 0:1.1.0-1.fc12

    Complete!
    [root@pcmk-1 x86_64]#

If this step fails, it is likely that your version/distribution does not ship the "Pacemaker" versions of dlm_controld and/or gfs_controld. Normally these files would be called `dlm_controld.pcmk` and `gfs_controld.pcmk` and live in the `/usr/sbin` directory.

If you cannot locate an installation source for these files, you will need to install a package called `cman` and reconfigure Corosync to use it as outlined in .

When using CMAN, you can skip where `dlm-clone` and `gfs-clone` are created, and proceed directly to after ensuring that `gfs2-utils` and `gfs2-cluster` were installed.

## Setup Pacemaker-GFS2 Integration

GFS2 needs two services to be running, the first is the user-space interface to the kernel’s distributed lock manager (DLM). The DLM is used to co-ordinate which node(s) can access a given file (and when) and integrates with Pacemaker to obtain node membership The list of nodes the cluster considers to be available information and fencing capabilities.

The second service is GFS2’s own control daemon which also integrates with Pacemaker to obtain node membership data.

### Add the DLM service

The DLM control daemon needs to run on all active cluster nodes, so we will use the shells interactive mode to create a cloned resource.

    [root@pcmk-1 ~]# crm
    crm(live)# cib new stack-glue
    INFO: stack-glue shadow CIB created
    crm(stack-glue)# configure primitive dlm ocf:pacemaker:controld op monitor interval=120s
    crm(stack-glue)# configure clone dlm-clone dlm meta interleave=true
    crm(stack-glue)# configure show xml
    crm(stack-glue)# configure show
    node pcmk-1
    node pcmk-2
    primitive WebData ocf:linbit:drbd \
            params drbd_resource="wwwdata" \
            op monitor interval="60s"
    primitive WebFS ocf:heartbeat:Filesystem \
            params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype="ext4"
    primitive WebSite ocf:heartbeat:apache \
            params configfile="/etc/httpd/conf/httpd.conf" \
            op monitor interval="1min"
    primitive ClusterIP ocf:heartbeat:IPaddr2 \
            params ip="192.168.122.101" cidr_netmask="32" \
            op monitor interval="30s"
    primitive dlm ocf:pacemaker:controld \
     op monitor interval="120s"
    ms WebDataClone WebData \
            meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true"
    clone dlm-clone dlm \
     meta interleave="true"
    location prefer-pcmk-1 WebSite 50: pcmk-1
    colocation WebSite-with-WebFS inf: WebSite WebFS
    colocation fs_on_drbd inf: WebFS WebDataClone:Master
    colocation website-with-ip inf: WebSite ClusterIP
    order WebFS-after-WebData inf: WebDataClone:promote WebFS:start
    order WebSite-after-WebFS inf: WebFS WebSite
    order apache-after-ip inf: ClusterIP WebSite
    property $id="cib-bootstrap-options" \
            dc-version="1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f" \
            cluster-infrastructure="openais" \
            expected-quorum-votes=”2” \
            stonith-enabled="false" \
            no-quorum-policy="ignore"
    rsc_defaults $id="rsc-options" \
            resource-stickiness=”100”

TODO: Explain the meaning of the interleave option

Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response

    crm(stack-glue)# cib commit stack-glue
    INFO: commited 'stack-glue' shadow CIB to the cluster
    crm(stack-glue)# quit
    bye
    [root@pcmk-1 ~]# crm_mon
    ============
    Last updated: Thu Sep  3 20:49:54 2009
    Stack: openais
    Current DC: pcmk-2 - partition with quorum
    Version: 1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f
    2 Nodes configured, 2 expected votes
    5 Resources configured.
    ============

    Online: [ pcmk-1 pcmk-2 ]

    WebSite (ocf::heartbeat:apache):        Started pcmk-2
    Master/Slave Set: WebDataClone
            Masters: [ pcmk-1 ]
            Slaves: [ pcmk-2 ]
    ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2
    Clone Set: dlm-clone
     Started: [ pcmk-2 pcmk-1 ]
    WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-2

### Add the GFS2 service

Once the DLM is active, we can add the GFS2 control daemon.

Use the crm shell to create the gfs-control cluster resource:

    [root@pcmk-1 ~]# crm
    crm(live)# cib new gfs-glue --force
    INFO: gfs-glue shadow CIB created
    crm(gfs-glue)# configure primitive gfs-control ocf:pacemaker:controld params daemon=gfs_controld.pcmk args="-g 0" op monitor interval=120s
    crm(gfs-glue)# configure clone gfs-clone gfs-control meta interleave=true

Now ensure Pacemaker only starts the gfs-control service on nodes that also have a copy of the dlm service (created above) already running

    crm(gfs-glue)# configure colocation gfs-with-dlm INFINITY: gfs-clone dlm-clone
    crm(gfs-glue)# configure order start-gfs-after-dlm mandatory: dlm-clone gfs-clone

Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response

    crm(gfs-glue)# configure show
    node pcmk-1
    node pcmk-2
    primitive WebData ocf:linbit:drbd \
            params drbd_resource="wwwdata" \
            op monitor interval="60s"
    primitive WebFS ocf:heartbeat:Filesystem \
            params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype="ext4"
    primitive WebSite ocf:heartbeat:apache \
            params configfile="/etc/httpd/conf/httpd.conf" \
            op monitor interval="1min"
    primitive ClusterIP ocf:heartbeat:IPaddr2 \
            params ip="192.168.122.101" cidr_netmask="32" \
            op monitor interval="30s"
    primitive dlm ocf:pacemaker:controld \
            op monitor interval="120s"
    primitive gfs-control ocf:pacemaker:controld \
     params daemon=”gfs_controld.pcmk” args=”-g 0” \
     op monitor interval="120s"
    ms WebDataClone WebData \
            meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true"
    clone dlm-clone dlm \
            meta interleave="true"
    clone gfs-clone gfs-control \
     meta interleave="true"
    location prefer-pcmk-1 WebSite 50: pcmk-1
    colocation WebSite-with-WebFS inf: WebSite WebFS
    colocation fs_on_drbd inf: WebFS WebDataClone:Master
    colocation gfs-with-dlm inf: gfs-clone dlm-clone
    colocation website-with-ip inf: WebSite ClusterIP
    order WebFS-after-WebData inf: WebDataClone:promote WebFS:start
    order WebSite-after-WebFS inf: WebFS WebSite
    order apache-after-ip inf: ClusterIP WebSite
    order start-gfs-after-dlm inf: dlm-clone gfs-clone
    property $id="cib-bootstrap-options" \
            dc-version="1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f" \
            cluster-infrastructure="openais" \
            expected-quorum-votes=”2” \
            stonith-enabled="false" \
            no-quorum-policy="ignore"
    rsc_defaults $id="rsc-options" \
            resource-stickiness=”100”
    crm(gfs-glue)# cib commit gfs-glue
    INFO: commited 'gfs-glue' shadow CIB to the cluster
    crm(gfs-glue)# quit
    bye
    [root@pcmk-1 ~]# crm_mon
    ============
    Last updated: Thu Sep  3 20:49:54 2009
    Stack: openais
    Current DC: pcmk-2 - partition with quorum
    Version: 1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f
    2 Nodes configured, 2 expected votes
    6 Resources configured.
    ============

    Online: [ pcmk-1 pcmk-2 ]

    WebSite (ocf::heartbeat:apache):        Started pcmk-2
    Master/Slave Set: WebDataClone
            Masters: [ pcmk-1 ]
            Slaves: [ pcmk-2 ]
    ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2
    Clone Set: dlm-clone
            Started: [ pcmk-2 pcmk-1 ]
    Clone Set: gfs-clone
     Started: [ pcmk-2 pcmk-1 ]
    WebFS   (ocf::heartbeat:Filesystem):    Started pcmk-1

## Create a GFS2 Filesystem

### Preparation

Before we do anything to the existing partition, we need to make sure it is unmounted. We do this by tell the cluster to stop the WebFS resource. This will ensure that other resources (in our case, Apache) using WebFS are not only stopped, but stopped in the correct order.

    [root@pcmk-1 ~]# crm_resource --resource WebFS --set-parameter target-role --meta --parameter-value Stopped
    [root@pcmk-1 ~]# crm_mon
    ============
    Last updated: Thu Sep  3 15:18:06 2009
    Stack: openais
    Current DC: pcmk-1 - partition with quorum
    Version: 1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f
    2 Nodes configured, 2 expected votes
    6 Resources configured.
    ============

    Online: [ pcmk-1 pcmk-2 ]

    Master/Slave Set: WebDataClone
            Masters: [ pcmk-1 ]
            Slaves: [ pcmk-2 ]
    ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-1
    Clone Set: dlm-clone
            Started: [ pcmk-2 pcmk-1 ]
    Clone Set: gfs-clone
            Started: [ pcmk-2 pcmk-1 ]

Note that both Apache and WebFS have been stopped.

### Create and Populate an GFS2 Partition

Now that the cluster stack and integration pieces are running smoothly, we can create an GFS2 partition.

This will erase all previous content stored on the DRBD device. Ensure you have a copy of any important data.

We need to specify a number of additional parameters when creating a GFS2 partition.

First we must use the -p option to specify that we want to use the the Kernel’s DLM. Next we use -j to indicate that it should reserve enough space for two journals (one per node accessing the filesystem).

Lastly, we use -t to specify the lock table name. The format for this field is clustername:fsname. For the fsname, we just need to pick something unique and descriptive and since we haven’t specified a clustername yet, we will use the default (pcmk).

To specify an alternate name for the cluster, locate the service section containing “name: pacemaker” in corosync.conf and insert the following line anywhere inside the block:

clustername: myname

Do this on each node in the cluster and be sure to restart them before continuing.

    [root@pcmk-1 ~]# mkfs.gfs2 -p lock_dlm -j 2 -t pcmk:web /dev/drbd1
    This will destroy any data on /dev/drbd1.
    It appears to contain: data

    Are you sure you want to proceed? [y/n] y

    Device:                    /dev/drbd1
    Blocksize:                 4096
    Device Size                1.00 GB (131072 blocks)
    Filesystem Size:           1.00 GB (131070 blocks)
    Journals:                  2
    Resource Groups:           2
    Locking Protocol:          "lock_dlm"
    Lock Table:                "pcmk:web"
    UUID:                      6B776F46-177B-BAF8-2C2B-292C0E078613

    [root@pcmk-1 ~]#

Then (re)populate the new filesystem with data (web pages). For now we’ll create another variation on our home page.

    [root@pcmk-1 ~]# mount /dev/drbd1 /mnt/
    [root@pcmk-1 ~]# cat <<-END >/mnt/index.html
    <html>
    <body>My Test Site - GFS2</body>
    </html>
    END
    [root@pcmk-1 ~]# umount /dev/drbd1
    [root@pcmk-1 ~]# drbdadm verify wwwdata
    [root@pcmk-1 ~]#

## Reconfigure the Cluster for GFS2

    [root@pcmk-1 ~]# crm
    crm(live)# cib new GFS2
    INFO: GFS2 shadow CIB created
    crm(GFS2)# configure delete WebFS
    crm(GFS2)# configure primitive WebFS ocf:heartbeat:Filesystem params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2”

Now that we’ve recreated the resource, we also need to recreate all the constraints that used it. This is because the shell will automatically remove any constraints that referenced WebFS.

    crm(GFS2)# configure colocation WebSite-with-WebFS inf: WebSite WebFS
    crm(GFS2)# configure colocation fs_on_drbd inf: WebFS WebDataClone:Master
    crm(GFS2)# configure order WebFS-after-WebData inf: WebDataClone:promote WebFS:start
    crm(GFS2)# configure order WebSite-after-WebFS inf: WebFS WebSite
    crm(GFS2)# configure colocation WebFS-with-gfs-control INFINITY: WebFS gfs-clone
    crm(GFS2)# configure order start-WebFS-after-gfs-control mandatory: gfs-clone WebFS
    crm(GFS2)# configure show
    node pcmk-1
    node pcmk-2
    primitive WebData ocf:linbit:drbd \
            params drbd_resource="wwwdata" \
            op monitor interval="60s"
    primitive WebFS ocf:heartbeat:Filesystem \
     params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2”
    primitive WebSite ocf:heartbeat:apache \
            params configfile="/etc/httpd/conf/httpd.conf" \
            op monitor interval="1min"
    primitive ClusterIP ocf:heartbeat:IPaddr2 \
            params ip="192.168.122.101" cidr_netmask="32" \
            op monitor interval="30s"
    primitive dlm ocf:pacemaker:controld \
            op monitor interval="120s"
    primitive gfs-control ocf:pacemaker:controld \
       params daemon=”gfs_controld.pcmk” args=”-g 0” \
            op monitor interval="120s"
    ms WebDataClone WebData \
            meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true"
    clone dlm-clone dlm \
            meta interleave="true"
    clone gfs-clone gfs-control \
            meta interleave="true"
    colocation WebFS-with-gfs-control inf: WebFS gfs-clone
    colocation WebSite-with-WebFS inf: WebSite WebFS
    colocation fs_on_drbd inf: WebFS WebDataClone:Master
    colocation gfs-with-dlm inf: gfs-clone dlm-clone
    colocation website-with-ip inf: WebSite ClusterIP
    order WebFS-after-WebData inf: WebDataClone:promote WebFS:start
    order WebSite-after-WebFS inf: WebFS WebSite
    order apache-after-ip inf: ClusterIP WebSite
    order start-WebFS-after-gfs-control inf: gfs-clone WebFS
    order start-gfs-after-dlm inf: dlm-clone gfs-clone
    property $id="cib-bootstrap-options" \
            dc-version="1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f" \
            cluster-infrastructure="openais" \
            expected-quorum-votes=”2” \
            stonith-enabled="false" \
            no-quorum-policy="ignore"
    rsc_defaults $id="rsc-options" \
            resource-stickiness=”100”

Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response

    crm(GFS2)# cib commit GFS2
    INFO: commited 'GFS2' shadow CIB to the cluster
    crm(GFS2)# quit
    bye
    [root@pcmk-1 ~]# crm_mon
    ============
    Last updated: Thu Sep  3 20:49:54 2009
    Stack: openais
    Current DC: pcmk-2 - partition with quorum
    Version: 1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f
    2 Nodes configured, 2 expected votes
    6 Resources configured.
    ============

    Online: [ pcmk-1 pcmk-2 ]

    WebSite (ocf::heartbeat:apache):        Started pcmk-2
    Master/Slave Set: WebDataClone
            Masters: [ pcmk-1 ]
            Slaves: [ pcmk-2 ]
    ClusterIP        (ocf::heartbeat:IPaddr):        Started pcmk-2
    Clone Set: dlm-clone
            Started: [ pcmk-2 pcmk-1 ]
    Clone Set: gfs-clone
            Started: [ pcmk-2 pcmk-1 ]
    WebFS (ocf::heartbeat:Filesystem): Started pcmk-1

## Reconfigure Pacemaker for Active/Active

Almost everything is in place. Recent versions of DRBD are capable of operating in Primary/Primary mode and the filesystem we’re using is cluster aware. All we need to do now is reconfigure the cluster to take advantage of this.

This will involve a number of changes, so we’ll again use interactive mode.

    [root@pcmk-1 ~]# crm
    [root@pcmk-1 ~]# cib new active

There’s no point making the services active on both locations if we can’t reach them, so lets first clone the IP address. Cloned IPaddr2 resources use an iptables rule to ensure that each request only processed by one of the two clone instances. The additional meta options tell the cluster how many instances of the clone we want (one “request bucket” for each node) and that if all other nodes fail, then the remaining node should hold all of them. Otherwise the requests would be simply discarded.

    [root@pcmk-1 ~]# configure clone WebIP ClusterIP  \
            meta globally-unique=”true” clone-max=”2” clone-node-max=”2”

Now we must tell the ClusterIP how to decide which requests are processed by which hosts. To do this we must specify the clusterip_hash parameter.

Open the ClusterIP resource

    [root@pcmk-1 ~]# configure edit  ClusterIP

And add the following to the params line

    clusterip_hash="sourceip"

So that the complete definition looks like:

    primitive ClusterIP ocf:heartbeat:IPaddr2 \
            params ip="192.168.122.101" cidr_netmask="32" clusterip_hash="sourceip" \
            op monitor interval="30s"

Here is the full transcript

    [root@pcmk-1 ~]# crm
    crm(live)# cib new active
    INFO: active shadow CIB created
    crm(active)# configure clone WebIP ClusterIP  \
            meta globally-unique=”true” clone-max=”2” clone-node-max=”2”
    crm(active)# configure show
    node pcmk-1
    node pcmk-2
    primitive WebData ocf:linbit:drbd \
            params drbd_resource="wwwdata" \
            op monitor interval="60s"
    primitive WebFS ocf:heartbeat:Filesystem \
            params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2”
    primitive WebSite ocf:heartbeat:apache \
            params configfile="/etc/httpd/conf/httpd.conf" \
            op monitor interval="1min"
    primitive ClusterIP ocf:heartbeat:IPaddr2 \
            params ip=”192.168.122.101” cidr_netmask=”32” clusterip_hash=”sourceip” \
            op monitor interval="30s"
    primitive dlm ocf:pacemaker:controld \
            op monitor interval="120s"
    primitive gfs-control ocf:pacemaker:controld \
       params daemon=”gfs_controld.pcmk” args=”-g 0” \
            op monitor interval="120s"
    ms WebDataClone WebData \
            meta master-max="1" master-node-max="1" clone-max="2" clone-node-max="1" notify="true"
    clone WebIP ClusterIP \
     meta globally-unique=”true” clone-max=”2” clone-node-max=”2”
    clone dlm-clone dlm \
            meta interleave="true"
    clone gfs-clone gfs-control \
            meta interleave="true"
    colocation WebFS-with-gfs-control inf: WebFS gfs-clone
    colocation WebSite-with-WebFS inf: WebSite WebFS
    colocation fs_on_drbd inf: WebFS WebDataClone:Master
    colocation gfs-with-dlm inf: gfs-clone dlm-clone
    colocation website-with-ip inf: WebSite WebIP
    order WebFS-after-WebData inf: WebDataClone:promote WebFS:start
    order WebSite-after-WebFS inf: WebFS WebSite
    order apache-after-ip inf: WebIP WebSite
    order start-WebFS-after-gfs-control inf: gfs-clone WebFS
    order start-gfs-after-dlm inf: dlm-clone gfs-clone
    property $id="cib-bootstrap-options" \
            dc-version="1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f" \
            cluster-infrastructure="openais" \
            expected-quorum-votes=”2” \
            stonith-enabled="false" \
            no-quorum-policy="ignore"
    rsc_defaults $id="rsc-options" \
            resource-stickiness=”100”

Notice how any constraints that referenced ClusterIP have been updated to use WebIP instead. This is an additional benefit of using the crm shell.

Next we need to convert the filesystem and Apache resources into clones. Again, the shell will automatically update any relevant constraints.

    crm(active)# configure clone WebFSClone WebFS
    crm(active)# configure clone WebSiteClone WebSite

The last step is to tell the cluster that it is now allowed to promote both instances to be Primary (aka. Master).

    crm(active)# configure edit WebDataClone

Change master-max to 2

    crm(active)# configure show
    node pcmk-1
    node pcmk-2
    primitive WebData ocf:linbit:drbd \
            params drbd_resource="wwwdata" \
            op monitor interval="60s"
    primitive WebFS ocf:heartbeat:Filesystem \
            params device="/dev/drbd/by-res/wwwdata" directory="/var/www/html" fstype=”gfs2”
    primitive WebSite ocf:heartbeat:apache \
            params configfile="/etc/httpd/conf/httpd.conf" \
            op monitor interval="1min"
    primitive ClusterIP ocf:heartbeat:IPaddr2 \
            params ip=”192.168.122.101” cidr_netmask=”32” clusterip_hash=”sourceip” \
            op monitor interval="30s"
    primitive dlm ocf:pacemaker:controld \
            op monitor interval="120s"
    primitive gfs-control ocf:pacemaker:controld \
       params daemon=”gfs_controld.pcmk” args=”-g 0” \
            op monitor interval="120s"
    ms WebDataClone WebData \
            meta master-max="2" master-node-max="1" clone-max="2" clone-node-max="1" notify="true"
    clone WebFSClone WebFS
    clone WebIP ClusterIP  \
            meta globally-unique=”true” clone-max=”2” clone-node-max=”2”
    clone WebSiteClone WebSite
    clone dlm-clone dlm \
            meta interleave="true"
    clone gfs-clone gfs-control \
            meta interleave="true"
    colocation WebFS-with-gfs-control inf: WebFSClone gfs-clone
    colocation WebSite-with-WebFS inf: WebSiteClone WebFSClone
    colocation fs_on_drbd inf: WebFSClone WebDataClone:Master
    colocation gfs-with-dlm inf: gfs-clone dlm-clone
    colocation website-with-ip inf: WebSiteClone WebIP
    order WebFS-after-WebData inf: WebDataClone:promote WebFSClone:start
    order WebSite-after-WebFS inf: WebFSClone WebSiteClone
    order apache-after-ip inf: WebIP WebSiteClone
    order start-WebFS-after-gfs-control inf: gfs-clone WebFSClone
    order start-gfs-after-dlm inf: dlm-clone gfs-clone
    property $id="cib-bootstrap-options" \
            dc-version="1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f" \
            cluster-infrastructure="openais" \
            expected-quorum-votes=”2” \
            stonith-enabled="false" \
            no-quorum-policy="ignore"
    rsc_defaults $id="rsc-options" \
            resource-stickiness=”100”

Review the configuration before uploading it to the cluster, quitting the shell and watching the cluster’s response

    crm(active)# cib commit active
    INFO: commited 'active' shadow CIB to the cluster
    crm(active)# quit
    bye
    [root@pcmk-1 ~]# crm_mon
    ============
    Last updated: Thu Sep  3 21:37:27 2009
    Stack: openais
    Current DC: pcmk-2 - partition with quorum
    Version: 1.1.5-bdd89e69ba545404d02445be1f3d72e6a203ba2f
    2 Nodes configured, 2 expected votes
    6 Resources configured.
    ============

    Online: [ pcmk-1 pcmk-2 ]

    Master/Slave Set: WebDataClone
            Masters: [ pcmk-1 pcmk-2 ]
    Clone Set: dlm-clone
            Started: [ pcmk-2 pcmk-1 ]
    Clone Set: gfs-clone
            Started: [ pcmk-2 pcmk-1 ]
    Clone Set: WebIP
     Started: [ pcmk-1 pcmk-2 ]
    Clone Set: WebFSClone
     Started: [ pcmk-1 pcmk-2 ]
    Clone Set: WebSiteClone
     Started: [ pcmk-1 pcmk-2 ]

### Testing Recovery

TODO: Put one node into standby to demonstrate failover