10 Virtual Pools

A virtual pool is a group of one or more virtual hosts with the same processor architecture that have access to the same virtual and physical networks and storage resources. Virtual pools provide load balancing, high availability capabilities, and sharing of some resources for all members of the pool.

A virtual host refers to Oracle VM Servers that are managed through Enterprise Manager Ops Center. A guest in a virtual pool refers to a logical domain running on an Oracle VM Server.

Virtual pools are resource pools of virtual hosts that share compatible chip architecture, which facilitates actions such as moving guests between hosts. You can also apply resource configurations and policies to them. The policies that you establish for a virtual pool manage many of the CPU utilization and resource balancing functions. Operations to the virtual pool are delegated to the individual virtual hosts in the virtual pool.

To manage the guests within a virtual pool, you can perform warm and live guest migration and you can balance all of the guests' load among the members of the virtual pool. You can configure a policy to balance the load automatically, based on a schedule that you determine, or you can balance the load manually. If a virtual host system shuts down for any reason, such as a hardware failure, you can start the guests on another virtual host in the same pool. All guests in the virtual pool can access the images contained in the virtual pool's storage library.

Each virtual host contains a hypervisor and its local resources and network connections. Virtual hosts in a virtual pool share network and storage libraries and several virtual pools can share the same networks and storage resources.

You can move a virtual host to another virtual pool or add a stand-alone or individually managed virtual host to a virtual pool.

Note:

virtual host can belong to only one virtual pool at a time.

Requirements for a Virtual Pool

To be added to a virtual pool, a virtual host must meet the following requirements:

  • Must have the same chip architecture as the other virtual hosts in the virtual pool to support load balancing and guest migration. Enterprise Manager Ops Center and Oracle VM Server for SPARC support SPARC T-Series chip architectures.

  • Must be running at least the Oracle VM Server for SPARC version 1.2 software.

    Must be running on at least the Solaris 10 10/09 OS and must meet specific patch and firmware requirements.

  • Must be on the same physical network as other virtual hosts in the virtual pool. The virtual hosts can be on several physical networks through multiple NICs, but must have at least one network in common with the other virtual hosts in the virtual pool. A good practice is to use a dedicated physical migration network.

  • The virtual host's guests must have been created using Enterprise Manager Ops Center. Any guests created through the native CLI cannot be managed by Enterprise Manager Ops Center.

  • The virtual host's guests must be in a shutdown state. Shutdown guests are no longer associated with the virtual host. After you add the virtual host to the virtual pool, you can associate the guest with any virtual host in the virtual pool.

Policies for a Virtual Pool

When you create a virtual pool, you define guest placement, and auto balancing polices. When you create guests, you define the guest resource consumption, including physical and virtual CPUs. You can edit the policies at any time.

Placement Policy

The Placement Policy determines the preferred virtual host for new guests within the virtual pool and how the virtual pool is balanced. The placement policy is defined when a virtual pool is created.The following are the placement policy options:

  • Place the guest on the virtual host with the lowest relative load, based on the lowest memory and CPU utilization. The calculation is based on a combination of the average load during one hour, one day and three weeks.

  • Place the guest on the virtual host with the lowest allocated CPU and memory, that is, the total static resource allocation across all guests on the host. The resource allocation is the sum of the number of vCPUs and virtual memory specified for each guest.

  • Place the guest on the virtual host that is consuming the least power.

To change the placement policy for a virtual pool, see Editing the Configuration of a Virtual Pool.

Example 10-1 Example of Least Allocated Virtual Host

A virtual pool has two virtual hosts with different CPU and memory allocations. Virtual Host A has eight available CPUs and 16 GB of memory. Virtual Host B has four available CPUs and 8 GB of memory.

Virtual host A has three guests:

  • Guest X has one vCPU and 1024 MB of memory.

  • Guest Y has two vCPUs and 2048 MB of memory.

  • Guest Z has one vCPU and 1024 MB of memory.

Virtual Host A's total static allocation is four vCPUs and four GB of memory.

Virtual host B has one guest:

  • Guest W has three vCPU and 4096 MB of memory.

Virtual Host B's total static allocation is three vCPUs and four GB of memory.

The allocation percentage for Virtual Host A is: CPU allocation is 4 vCPUs/8 physical CPUs, or 50%. Memory allocation is 4 GB/16 GB or 25%.

The allocation percentage for Virtual Host B is: CPU allocation is 3 vCPUs/4 physical CPUs or 75%. Memory allocation is 4 GB/8 GB or 50%

Therefore, Virtual Host A is the less or least allocated of the virtual hosts.

How Power Minimization Policy Works

The power minimization policy can be used only when the virtual host has the capacity to report its power usage. To report power usage, a virtual host must have ILOM version 2.x or 3.x.

This power minimization policy consolidates guests into the optimal set of virtual hosts. The idle virtual hosts are powered off or set to low-power mode on explicit approval.

Automatic Load Balancing Policy

Use the Automatic Load Balancing Policy to schedule load balancing within a virtual pool. You can schedule the automatic balancing to occur weekly, daily, or hourly on a specific day and time of the week. The default is to balance the load on the hosts in the virtual pool every Saturday at midnight according to the defined placement policy.

Note:

The day and time are in the Enterprise Controller's time zone.

If you do not want to balance the virtual pool's load automatically, you can schedule a reminder to rebalance the virtual pool's load manually.

Libraries for a Virtual Pool

Enterprise Manager Ops Center uses storage libraries to store ISO images and guest metadata. Software libraries are also used to provide storage disks for the guest operating systems and for guests' data.

The virtual hosts in a virtual pool can get access to and share any storage and networks associated with the virtual pool. If you add a virtual host to a virtual pool, the libraries associated with that virtual host become available to all the other virtual hosts in the virtual pool.

Networks for a Virtual Pool

Networks enable virtual hosts and guests to communicate with each other or through the Internet. Each network has its own values for parameters such as an IP address, subnet, time server, NIS, and DHCP information. Guests in the network communicate with each other or with the Internet through these hosts.

A managed network depends on the physical network interface card (PNIC) that is available to the virtual host. You can create one managed network for each physical network interface card. If one host has two PNICs, it is a good practice to create two managed networks: a management network and a data network. This configuration lets you place all the guests on the data network, and reserving the management network for access to internal resources of the data center.

When you assign a network to a virtual pool, the network becomes accessible to all virtual hosts in the pool. All virtual hosts in a virtual pool belong to the same set of networks. At least one network must be assigned to a virtual pool to ensure that when you migrate a guest from one virtual host to another virtual host within the pool, the guest can still access the network.

Guests communicate with the networks through their virtual host. When you add a virtual host to a virtual pool, the virtual host is also configured for all the associated networks for the virtual pool. In this way, the virtual host can access all of the networks defined for the pool and be an active member of the pool.

You can associate a network multiple times on the same Oracle VM Server. The multiple connections are made through different switches on the Oracle VM Server. For each network connection, a virtual switch is created for the network that connects to only one NIC at a time. The naming pattern for the switches relies on the Oracle VM Server. If an Oracle VM Server is connected to a network, for example network 1.1.1.0/24, the name of the virtual switches is 1.1.1.0_24, 1.1.1.0_24_1, 1.1.1.0_24_2 and 1.1.1.0_24_3. When a network connection is made to the Oracle VM Server, the virtual switch created is incremented.

You can assign a network multiple times to a virtual pool. The network is deployed the same number of times on each virtual host of the virtual pool. Also, the switches that are created for each network connection are same on the virtual hosts. This ensures that the logical domain can be migrated across the virtual hosts in the virtual pool. To migrate a logical domain, the switch name must be the same on the source and target virtual hosts..

See Managing Networks of a Virtual Pool for detailed information about networks in a virtual pool.

Viewing the Configuration of a Virtual Pool

The Virtual Pool Dashboard displays the characteristics and uses for a virtual pool.

To Display Virtual Pool Details

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool from the All Assets drop-down list.

  3. Select a virtual pool. The Dashboard page for the virtual pool is displayed in the center pane with the following tabs:

    • Summary – Details about the virtual pool, including the policies, attached virtual hosts, guests, and resource load.

    • Associated Libraries – List of libraries for the virtual pool, their sizes, the guests that use each library, and the contents of each library. Library contents include image type, modification date, and size.

    • Available Networks – List of virtual networks for the virtual pool, including network name, IP address, netmask, and description.

    • Charts – Enables you to create CPU, memory, and network usage charts.

    • Logs – Provides a record of recent activity.

Creating a Virtual Pool

You can create a new virtual pool with one or more virtual hosts that share the physical and virtual networks and storage resources.

To add a virtual host to an existing virtual pool, see Adding an Oracle VM Server to a Virtual Pool.

Before You Begin

  • Review Requirements for a Virtual Pool.

  • Decide on the placement policy for this virtual host's guests.

  • Decide on the balancing policy for this virtual host, if any.

  • Identify the virtual host to be added to the new virtual pool:

    • Be a managed virtual host or a pooled host.

    • Have no guests.

    • Be in a healthy state.

    • Cannot be the only virtual host in another virtual pool.

    • Have a compatible chip architecture with the other virtual hosts that you wan to add to the virtual pool.

    • Be compatible with the CPU frequency of other Oracle VM Server

To Create a Virtual Pool

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool from the drop-down list.

  3. Click Create Virtual Pool in the Actions pane.

  4. Provide a name and description for the new virtual pool, and assign tags. Tags are keywords that you can use to help identify the virtual pool. Click Next.

  5. Select how new guests are allocated to a virtual host in the virtual pool, according to one of the following policies:

    • Lowest relative load

    • Least allocated CPU and memory resources

    • Least power consumption

  6. Select how loads are balanced within the virtual pool according to one of the following policies:

    • Manual balancing, the default

    • Automatic balancing, which reviews the load on the host for the interval and day that you request and migrates the guests, as needed, to balance the load. You can require administrator approval before the guests are moved.

  7. Assign one or more networks to the virtual pool from the list of available networks.

  8. Specify the number of connections for the selected network. The number of connections is also the number of virtual switches.

  9. To allow guests to move between virtual hosts, click the Migration check box to designate the network as a Migration Network. Migration networks enable you to isolate guest migration traffic to a subset of the Networks in the pool. You can designate more than one network as a migration network.

  10. Select an Oracle VM Server from the list to define the architecture of the virtual pool. Click Next.

  11. Select one or more Oracle VM Servers from the list of virtual hosts that match the chip architecture to add to virtual pool. Click Next.

    Note:

    If the Oracle VM Server you select is already in another virtual pool, the server moves from its current virtual pool to the new virtual pool. An Oracle VM Server can belong to only one virtual pool.
  12. For each network connection requested in Step8, specify the NIC and IP address to create the virtual switch.

  13. For each IP address, select either Use Static IP and provide the IP address or select Assign by DHCP to obtain the IP address from the DHCP server as needed. Click Next.

  14. From the list of available storage libraries, select ast least one NAS storage library to associate with the virtual pool. Click Next.

  15. Review the summary and details of the new virtual pool. Click Finish to submit a job that creates the new virtual pool.

Editing the Configuration of a Virtual Pool

You can edit the following virtual pool attributes:

  • Name

  • Description

  • Tags

  • Placement Policy

  • Auto Balancing Policy

  • Load Balancing Schedule

Before you change a policy for a virtual pool, review the relationship between the physical and virtual CPUs, that is, its placement policy. Each virtual pool has a placement policy that defines how guests are placed:

  • Place the guest on the virtual host with the lowest relative load.

  • Place the guest on the virtual host with the lowest allocated CPU and memory.

  • Place the guest on the virtual host which is consuming the least power.

Auto-balancing changes the allocation of resources defined by the placement policy. The load is balanced by migrating a guest to a different virtual host in the same virtual pool

You can choose to balance the load on a schedule that you define, or you can balance the load manually. The Auto Balance policy is set for each virtual pool.

To Edit Virtual Pool Attributes

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool from the All Assets drop-down list.

  3. Select a virtual pool. The Dashboard page for the virtual pool is displayed in the center pane.

  4. Click Edit Virtual Pool Attributes in the Actions pane.

  5. To change the name or description of the virtual pool or to change its tags, enter new text in the text box.

  6. To change the Placement Policy or Auto Balancing Policy, select the new policy. Select the date interval, time interval, and time of day to change the auto balance or to send a reminder to balance the load manually.

  7. Click Save

Adding an Oracle VM Server to a Virtual Pool

An Oracle VM Server can belong to only one virtual pool. You can add an Oracle VM Server to a virtual pool at any time if it meets the following requirements:

  • A stand-alone Oracle VM Server, that is, an individually managed virtual host

  • Does not have running or suspended logical domains.

  • In a healthy state

  • Cannot be the only Oracle VM Server in another virtual pool

  • Has a compatible chip architecture with the other virtual hosts in the virtual pool

  • Compatible with the CPU frequency of other Oracle VM Servers in the virtual pool.

Note:

If the Oracle VM Server you add to the virtual pool has network connections that are not available to the virtual pool, those connections are broken and no longer available to the Oracle VM Server.

To Add an Oracle VM Server to a Virtual Pool

  1. Click Virtual Pools in the Assets view of the Navigation pane.

  2. Select the Virtual Pool to which you want to add the Oracle VM Server.

  3. Click Add Oracle VM Server in the Actions pane.

  4. Select one Oracle VM Server from the list of eligible Oracle VM Servers in the table. Click Next.

  5. Review the summary of the virtual pool and the new virtual host. Click Finish to submit a job that adds the Oracle VM Server to the virtual pool.

Removing an Oracle VM Server From a Virtual Pool

You cannot remove an Oracle VM Server from a virtual pool if it is the only virtual host in the virtual pool or if it has any running or suspended guests.

When you remove an Oracle VM Server from a virtual pool, the server becomes an individually managed server. The virtual pool's libraries and networks are no longer available to the server. Instead, the Oracle VM Server uses the default local library and management network.

Before You Begin

  • Shut down all the guests associated with a virtul pool.

  • If the Oracle VM Server's state is unknown, you can force the removal of the server from the virtual pool. A forced removal shuts down and disassociates all guests from the server.

To Remove an Oracle VM Server From a Virtual Pool

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool in the drop-down list.

  3. Select the virtual pool.

  4. Select the Summary tab in the center pane. The list of Oracle VM Servers in the virtual pool are listed.

  5. Select an Oracle VM Server from the list.

  6. Click the Remove from Virtual Pool icon.

  7. In the window, click Remove from Virtual Pool to start a job that removes the Oracle VM Server from the virtual pool . If the host state is unknown, click Force Remove Virtual Host in the dialog box.

Managing Storage Libraries of a Virtual Pool

When you create a new NAS storage library, you can also associate it with a virtual pool. Use the following procedure to associate an existing storage library with a virtual pool.

To Associate a Storage Library With a Virtual Pool

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool from the drop-down list. All the virtual pools are listed.

  3. Select a virtual pool.

  4. Click Associate Libraries from the Actions pane. The Associate Library window is displayed.

  5. Select the libraries from the list.

  6. Click Associate Library. The selected libraries are associated with the virtual pool.

To Disassociate a Library from Virtual Pool

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool from the drop-down list.

  3. Select the virtual pool from the list.

  4. Select the Libraries tab in the center pane. The libraries that are associated with the virtual pool are listed.

  5. Select the library that you want to disassociate from the virtual pool. Check the usage and contents of the library before disassociating it.

  6. Click the Disassociate Library icon. The Disassociate Library window is displayed.

  7. Click Disassociate Library to confirm unmounting the library.

Managing Networks of a Virtual Pool

You can assign networks to virtual pool and define the number of connections for each network. For each network connection, a virtual switch is created. You need to define the NIC and the IP address for each network connection.

To Assign a Network to a Virtual Pool

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool from the drop-down list.

  3. Select the virtual pool.

  4. Select Attach Network from the Actions pane. The Assign Network wizard is displayed.

  5. Select a network from the list and enter the number of connections for the network. You can add more than one network. Click Next.

  6. Select a NIC from the list and specify how it connects to the network. The list of NICs includes NICs that are not used by other networks and NICs that are bound to other networks, identified by the network's VLAN tag. You can select a NIC bound to a network if the network has a different VLAN tag. Select NICs so that all the virtual hosts have the same virtual switch name. The attach network job fails if the switch names.

  7. For each network connection, choose the Static IP Adress option and provide an IP address, or select the Assign to DHCP option to allocate the IP address as needed. Enter the IP address in the DHCP Client ID field. Click Next.

  8. Review the selections you have maded. Click Finish to assign the networks. The networks are assigned to the virtual pool and are available to all the guests of all the virtual hosts in the pool.

To Unbind a Network From a Virtual Pool

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool from the drop-down list..

  3. Select the virtual pool.

  4. Select the Networks tab in the center pane. The networks for the virtual pool are listed.

  5. Select the network that you want unbind.

  6. Click the Unbind Network From Virtual Pool icon.

  7. Click Unbind to confirm disassociating the network.

Deleting a Virtual Pool

Deleting a virtual pool removesthe association among the virtual hosts and removes all pool-specific library and network connections. The virtual hosts in the virtual pool become individual virtul servers relying on default network connections..

To Delete a Virtual Pool

  1. Select Assets from the Navigation pane.

  2. Select Virtual Pool in thedrop-down list.

  3. Select the virtual pool.

  4. Click Delete Virtual Pool in the Actions pane.

  5. Click Delete Virtual Pool to confirm action.