This is the list of the most frequently asked questions about Power and Capacity Management released for XenApp 5 Feature Pack on Windows Server 2003.

Q: Are there any plans on localizing the Management Console to a language other than English?

A: No. The Power and Capacity Management Console in the Cache release is only available in English. And currently there are no plans to localize the Parra version.

Q. Can the Power and Capacity Management agent be installed by using a Group Policy Object (GPO)?

A: This is not tested, but there should be no reason why it cannot work.

Q. How does a combination of XenServer with virtual XenApp work? Therefore, is it possible to first shut down the unnecessary XenApp servers and then the unnecessary physical servers running XenServer?

A: Power and Capacity Management does not manage the XenServers. It only manages XenApp servers. Therefore, if you have no virtual XenApp servers running on a XenServer it is still powered on. You might still have non-XenApp workloads running, such as Web servers or e-mail servers. But you can use other management tools to power manage the hypervisor.

Q. Is it possible to install the Power and Capacity Management agent in a "standard" Provisioning Server image?

A: Yes. Power and Capacity Management works with Wake on LAN option, which is how Provisioning Server works to deliver images to bare metal. Wake on LAN option is supported in addition to virtual machines for Power and Capacity Management.

Q. Can I provision the XenApp servers with provisioning server, and if it can, is there a special configuration required to configure the Wake on LAN option?

A: Yes. The system first tries to determine whether the machine to wake is a virtual machine, by querying the configured machine managers. If no match is found, then the Concentrator simply broadcasts the Wake on LAN packet. Therefore, there is no specific Wake on LAN configuration in Power and Capacity Management. However, for Wake on LAN to work, the target devices must be Wake on LAN enabled and exist on the same subnet as the Concentrator.

Q. Must I also choose the Wake on LAN option if the provisioned XenApp server is a virtual server on XenServer?

A: You can have a single Provisioning Services image to work across physical or virtual deployments. Even when using Provisioning Services, if you are booting servers by using the XenServer, then you must choose XenServer. If you are booting by using Wake on LAN option on the physical hardware, then you must choose Wake on LAN.

Q. Can Power and Capacity Management and SCOM work together?

A: Out of the box, we are not planning any integration with operations manager. However, everything being done through the GUI can be done through WMI, so this can be customized.

Q. Should you install the Concentrator on a XenApp server?

A: No. You must not install the Concentrator on a XenApp server that host users sessions. You cannot power manage it if you do. Also, Concentrators can manage servers across farms. Therefore, you must have a farm-independent server if you can do so.

Q. Instead of number of sessions, is there a way to set the Capacity by percentage of Server resource utilization such as, CPU, RAM, or Page File Usage?

A: Yes. Power and Capacity Management provides a feature called dynamic capacity estimation. The remaining capacity of each server is continually being recalculated based on a combination of the typical session capacity value set by the administrator and the load as determined by the XenApp load evaluators.

Q. In terms of new session distribution, what takes precedence, the XenApp load evaluator or the Power and Capacity Management evaluator?

A: Power and Capacity Management takes precedence for server power on or off and consolidation only. For load distribution, the XenApp load evaluators are used.

Note that Power and Capacity Management adjusts the load evaluation for servers that are not selected to receive sessions. Power and Capacity Management keeps up to "Minimum Available Servers" available for logon. Other server load evaluators are set to 20,000.
Note: You can see that if you run QFARM /load command.

Q. How do you modify server monitoring to allow servers to shut down and suppress alerts?

A: EdgeSight already differentiates between planned and unplanned restarts. Because restarts initiated by Power and Capacity Management are planned restarts, you should be able to create alerts only for unplanned reboots.

Q. What is the process of draining a server? Some users stay logged in for more than 8 hours if you have published a desktop. Some users also work in shifts.

A: Power and Capacity Management selects up to "Minimum Available Servers" to accept logons. All other servers have the LE values set to 20,000 and therefore cannot select to host applications or desktops. When an available server reaches the optimal load, the server with highest load but under optimal load is chosen to receive logons. Draining is a side-effect of this model. As shift workers start to log on, they log on to the highest loaded servers under optimal load policy. As the previous shift logoff, the servers automatically drain until empty. The new shift only consumes enough servers to meet its demand.

Q. If you provision server through Provisioning Services with the agent already installed and configured for a workload called "office 2003", and if you want to change the workload to "office 2007" do you need to change or create a new Provisioning Services image to reflect this change?

A: Workloads can be assigned by using GPO. It is possible to use the same Provisioning Services image for more than one Power and Capacity Management workload. In this example, if Office is virtualized by using App-V or Streaming, then the same image could be used.

Q. Is Windows Server 2008 supported?

A: No. There is no plan to support Power and Capacity Management on Windows Server 2008.

Q. Can you install the agent on each XenApp server? Instead of changing the workload on each physical server, can you change it from the Management console?

A: The workload associated with an Agent cannot be changed from the management console. It must be changed on each individual XenApp server that you like to modify.

Q. What are the configuration steps, if you decide to implement Wake on LAN, and the XenApp servers are spread across several subnets and you decide to put a Concentrator in each subnet? How would you configure each Concentrator to point to the same SQL database? Do you need to have a separate farm for each Concentrator?

A: Each Power and Capacity Management farm is managed by one Master Concentrator, with multiple slaves for High Availability purposes. You cannot configure multiple Concentrator Masters to point to same Power and Capacity Management Database. So there is no support for Wake on LAN across subnets. You need a separate Power and Capacity Management farm for each subnet, if you want to support Wake on LAN for servers in different subnets.

Q. Does Power and Capacity Management have a way to backup its database in case of a failure?

A: No. Power and Capacity Management does not have a backup mechanism to backup or restore a database. Alternatively, if you have a database configured on an SQL server, you can use the SQL backup and restore functionality.

Q. If I have several concentrators configured in my environment can I view them all in one console?

A: Yes. You can use the Microsoft MMC snap-in to aggregate the consoles all in one place.

Q. How does load balancing work in Power and Capacity Management?

A: Load balancing works the same way as before; only now load consolidation removes various servers from the pool so that load balancing only works on a selected few server designated to take the load. If you have five servers, and load consolidation wants to load consolidate to only two servers. Power and Capacity Management disables three servers from taking new logons, indicating that the remaining two servers share the load. Standard XenApp load balancing starts and the server that has the lowest load index takes the next session. How the load index is calculated is exactly the same as before.

Q. Does Power and Capacity Management support SQL authentication?

A: No. Power and Capacity Management uses Windows authentication only in SQL Server. Power and Capacity Management does not use SQL authentication because the security model is weak and is really only used by legacy database applications.

Q. How many Power and Capacity Management farms can you have? Is there a limit? When can you suggest the use of multiple farms?

A: There is no said limit on Power and Capacity Management farms. Like XenApp, you might want to use multiple farms to reflect some distinguishing factor of the XenApp servers, or to make administration of many servers simpler by reducing the number of server in any one farm.

Q. Do you need another Concentrator if the XenApp server is located in another XenServer pool or if you want one Concentrator to span across several other pools?

A: That restriction was in Tech Preview. In the Cache release, a Xen virtual machine can be in any XenServer pool, provided that you have configured the new Machine Manager with the details of XenServer ‘manager’ of each pool.

Q. How does Wake on LAN work with Power and Capacity Management?

A: Power and Capacity Management uses broadcast Wake on LAN on port 9 (UDP 255.255.255.255:9), which implies routers must forward this traffic to bridge networks. Essentially, all physical machines to be powered on must exist on the same subnet. The alternative Wake on LAN methods you considered were unicast and subnet-directed broadcast. Unfortunately unicast Wake on LAN option is not support by all NIC hardware manufacturers and subnet-directed suffers the same problem as broadcast; nothing routes it.

Q. How many farms and workload can the SQL and SQL Express hold?

A: Database size is going to strongly depend on the data retention policy of metric data recorded by the Concentrator (see Configuration settings in Console). SQL Express 2008 has a 4 GB limit per instance, which is more than enough space to store the static data for thousands of servers and workloads. For dynamic metric data, assume about a few hundred bytes per server every 5 minutes; likewise for per workload. SQL Express could be used where High Availability and manageability of the database are low priorities. Definitely if deploying a cluster of Concentrators, a SQL Server cluster is recommended to ensure end-to-end availability.

Q. Does Power and Capacity Management require Active Directory integration and service connection points (SCP)?

A: Yes. The reason for Power and Capacity Management not using the ZDC is to intentionally remain loosely coupled with XenApp. By remaining independent from the XenApp codebase, Power and Capacity Management was developed rapidly and helps us develop the additions we have planned. The architecture also considered that Power and Capacity Management might monitor or control workloads other than XenApp in future.