XenDesktop 5 Study – Part 1
Identifying Pre-installation Requirements
Determine the requirements for the SQL (controller) database based on a description of an environment.
Supported Databases:
- SQL Server 2008 R2
- SQL Server 2008 R2 Express (Default for Quick Deploy)
- SQL Server 2008 SP1 or later
HA Approaches
- SQL Mirroring
- Hypervisor HA
- SQL Clustering
Determine desktop storage requirements based on a given environment
5000 Unmanaged Desktops will use approximately 40MB of DB space.
5000 Provisioned (MCS) Desktops will use approximately 59MB of DB space
5000 Desktops can generate approximately 8GB of transaction logs in 24 hours. Recommend using simple backups or frequent full backups for DB maintenance.
Based on a described environment or requirements, determine the optimal write cache location
Device Hard Drive - Stores the write cache on the target device's hard drive. Removes resources load from the Provisioning Server.
Device Hard Drive Persistent - Same as Device Hard Drive, but persists between reboots.
Device RAM - Puts the write cache in the target device RAM, very fast, but may be limited space.
Server Disk - Writes the cache back to the Provisioning Server, puts heavy I/O and network load on the server (this is the default setting for vDisks).
Server Disk Persistent - As above, but persists between reboots. All persistent files are invalidated if the master vDisk is changed.
Based on a description of an environment, determine the number of controllers and/or Provisioning services servers required for a XenDesktop environment
Rules for XenDesktop Controllers:
- N+1 Always ensure there is extra (controller) capacity in event of failure.
- 125-180 Desktop Registration per dedicated CPU Core
- 100-120 Logins per minute per dedicated CPU Core
2 Controller VMs with: 2x vCPU, 4GB of RAM providing Provsioning Services powered desktops can handle 2500 Desktops with an average launch and logon operation of 2.5 seconds.
Assumes resources, especially SQL, are not overcommitted.
Provisioning Services (5.6 SP1)
- Minimum spec is: 2GHz CPU, 2GB of RAM, 100Mbit NIC, Server 2003 SP2.
- Recommended: 3.5GHz DualCore/HT or higher, 4GB or higher, Dual 1GB NIC
- Virtual Provisioning Servers are supported
- Virtual Provisioning Server with 4vCPU, 40GB of RAM and a 10GB NIC can support 1500+ target devices per server with write cache on target device.