Citrix Systems 5.6 Creating a resource pool

Note:

The requirement for a XenServer host to have a static IP address to be part of a resource pool also applies

to servers providing shared NFS or iSCSI storage for the pool.

Although not a strict technical requirement for creating a resource pool, the advantages of pools (for

example, the ability to dynamically choose on which XenServer host to run a VM and to dynamically move

a VM between XenServer hosts) are only available if the pool has one or more shared storage repositories.

If possible, postpone creating a pool of XenServer hosts until shared storage is available. Once shared

storage has been added, Citrix recommends that you move existing VMs whose disks are in local storage

into shared storage. This can be done using the xe vm-copy command or XenCenter.

Creating a resource pool

Resource pools can be created using either the XenCenter management console or the CLI. When you join

a new host to a resource pool, the joining host synchronizes its local database with the pool-wide one, and

inherits some settings from the pool:

• VM, local, and remote storage configuration is added to the pool-wide database. All of these will still be

tied to the joining host in the pool unless you explicitly take action to make the resources shared after

the join has completed.

• The joining host inherits existing shared storage repositories in the pool and appropriate PBD records are

created so that the new host can access existing shared storage automatically.

• Networking information is partially inherited to the joining host: the structural details of NICs, VLANs and

bonded interfaces are all inherited, but policy information is not. This policy information, which must be

re-configured, includes:

• the IP addresses of management NICs, which are preserved from the original configuration

• the location of the management interface, which remains the same as the original configuration. For

example, if the other pool hosts have their management interface on a bonded interface, then the joining

host must be explicitly migrated to the bond once it has joined. See To add NIC bonds to the pool master

and other hosts for details on how to migrate the management interface to a bond.

• Dedicated storage NICs, which must be re-assigned to the joining host from XenCenter or the CLI, and

the PBDs re-plugged to route the traffic accordingly. This is because IP addresses are not assigned

as part of the pool join operation, and the storage NIC is not useful without this configured correctly.

See the section called “Configuring a dedicated storage NIC” for details on how to dedicate a storage

NIC from the CLI.

1. Open a console on XenServer host host2.

2. Command XenServer host host2 to join the pool on XenServer host host1 by issuing the command:

xe pool-join master-address=<host1> master-username=<administrators_username> \

master-password=<password>

The master-address must be set to the fully-qualified domain name of XenServer host host1 and

the password must be the administrator password set when XenServer host host1 was installed.

• XenServer hosts belong to an unnamed pool by default. To create your first resource pool, rename the

existing nameless pool. Use tab-complete to find the pool_uuid: