Resource Pool Requirements

(From the Admin Guide)

Requirements for creating resource pools

A resource pool is an aggregate of one or more homogeneous XenServer Hosts, up to a maximum of 16.

• each CPU is from the same vendor (in particular AMD-V and Intel VT CPUs cannot be mixed)
• each CPU is the same model (except for stepping)
• each CPU has the same feature flags
• it has a static IP address (either manually assigned or via DHCP);
• it is not a member of an existing resource pool
• it has a clock synchronized to the pool master server (for example, via NTP)
• it has no shared storage configured
• there are no running or suspended VMs on the XenServer Host which is joining
• there are no active operations on the VMs in progress, such as one shutting down
• the management NIC of the XenServer Host which is joining is not part of a NIC bond
• the Linux Pack is either installed on all hosts in the pool, or not installed at allXenServer Hosts in resource pools may contain different numbers of physical network interfaces. Local storage repositories may also exist, of varying size.

In practice, it is often difficult to obtain multiple servers with the exact same CPUs, and so minor variations are permitted. If you are sure that it is acceptable in your environment for hosts with varying CPUs to be part of the same resource pool, then the pool joining operation can be forced

Please note the constraint about NIC bonds above. We've heard reports of customers glossing over this requirement and running into errors.