1. Planning and Implementation of a Provisioning High Availability (HA) Solution Keith T McLaughlin Escalation Engineer

2. Training Agenda Overview of two different High Availability configurations Deeper look at High Availability Architecture Design and Implementation Troubleshooting Tips

3. Two different HA Configurations Distributed HA Centralized HA

4. Distributed HA Provisioning Servers SQL Server vDisks SQL database Target Devices

5. Centralized HA Provisioning Servers Shared Storage vDisks SQL database Target Devices SQL Server

6. High Availability Design Agenda item number 1 Cache’s roll in High Availability The roll of the bootstrap file in failover Re-login Process Load Balancing with High Availability How does failover work?

7. Failover Process 1.1.1.1 1.1.1.2 1.1.1.3 1.1.1.4 Streaming from 1.1.1.4 X Bootstrap 1.1.1.2 1.1.1.1 Login Process Request for vDisk3 PVS Target Device StreamServer 1.1.1.3:vDisk3

8. Bootstrap’s roll in failover The Target Device uses the list of Provisioning Server provided in the bootstrap when initiating failover.

9. Role of the bootstrap Shared Storage vDisks SQL database Target Devices SQL Server PVS3 PVS1 PVS2 PVS6 PVS5 PVS4 Bootstrap PVS1 PVS2 PVS3 PVS4

10. Load balancing with High Availability PVS currently only provides load balancing during the login process. A count of how many devices are booted to each server in the site is kept by the stream service. When a Target Device is shutdown or a new Target Device is booted up the server will update the count and send that information to all other servers in the site.

11. Load balancing with High Availability (cont) Load balancing will not occur dynamically after the login process. PVS2 PVS1

12. Load balancing with High Availability (cont) PVS2 PVS1 X

13. Where to store the cache file in a HA environment Cache on local RAM Cache on Server Disk Cache on Local Disk

14. Cache on Local RAM Shared Storage vDisks SQL database Cache PVS1 PVS2 X

15. Cache on Local Disk Shared Storage vDisks SQL database Cache PVS1 PVS2 X

16. Cache on Server Disk Shared Storage vDisks SQL database Cache PVS1 PVS2 X

17. Cache on Server Disk (incorrect configuration) Shared Storage vDisks SQL database Cache PVS1 PVS2 X

18. Possible single point of failure Shared Storage vDisks SQL database Cache PVS1 PVS2 TFTP DHCP PXE Switch

19. Possible single points of failure TFTP Network Storage Bootstrap Delivery

20. TFTP Redundancy DHCP Option 66 only allows for one TFTP server to be entered. Using TFTP Clustered Servers or PXE Service instead of DHCP options will solve this issue.

21. Network Redundancy PVS Server Target Device Switch PVS Server Target Device

22. Storage Redundancy Type of StorageProsCons CIFS on Windows Server Easy to setup Free with OS Hard drives are cheap Performance due to SMB traffic Lack of scalability HA requires two plus servers CIFS on NAS Device  Easy to setup  Device typically less expensive than SAN device  Built in redundancy for disks (depends on vendor/model)  Various vendors/models Less expensive solutions equal single point of failure Scalability can be an issue depending on vendor/model purchased

23. Storage Redundancy (continued) iSCSI to NAS Device  Moderate to setup  Device typically less expensive than SAN device  Built in redundancy for disks (depends on vendor/model)  Various vendors/models offer resiliency benefits Less expensive solutions equal single point of failure Scalability can be an issue depending on vendor/model purchased Requires cluster file system when sharing LUN across multiple servers iSCSI to SAN Device Highly scalable Built in resiliency Build in features like storage replication and high performance disk arrays Moderate to complex to setup Typically more expensive than NAS devices Requires cluster file system when sharing LUN across multiple servers

24. Storage Redundancy (continued) Fiber to SAN Device Highly scalable Built in resiliency Build in features like storage replication and high performance disk arrays Complex to setup Typically more expensive than NAS devices Requires cluster file system when sharing LUN across multiple servers

25. Bootstrap Delivery Redundancy SolutionProsCons DHCP Clustering Less traffic on the network Moderate to setup Multiple servers needed More expensive Multiple PXE Servers  Easy to setup  Less hardware needed. More broadcast traffic on the network

26. Troubleshooting Tips Stream Logs

27. PVS Logging Log files and the stream_log.config files can be found in C:\Documents and Settings\All Users\Application Data\Citrix\Provisioning Server To increase the logging level edit the level value line in the stream_config to TRACE

28. PVS Logging [0x000 00188]TRACECStreamDbImpl::DoDeviceGetByMac - In DoDeviceGetByMac for mac = E27AE23D9F48 [0x000 00188]TRACECSqlCommand::CSqlCommand - new CSqlCommand commandText: [0x000 00188]TRACECClientDeviceInstanceDbAccess::DoGetOne - In CClientDeviceInstanceDbAccess::DoGetOne [0x000 00188]DEBUGCClientDeviceInstanceDbAccess::DoGetOne - got device record, name = WinXp, mac = E27AE23D9F48 [0x000 00188]DEBUGCStreamDbImpl::DoDiskLocatorGetByDeviceId - In DoDiskLocatorGetByDeviceId for id = 1 [0x000 00188]TRACECDiskLocatorInstanceDbAccess::DoGetByDeviceId - In CDiskLocatorInstanceDbAccess::DoGetByDeviceId [0x000 00188]TRACECSqlCommand::CSqlCommand - new CSqlCommand commandText: [0x000 00188]DEBUG CDiskLocatorInstanceDbAccess::DoGetByDeviceId - harvested diskLocator info, diskLocatorId = 26fd6469-a761-4d0f- ae65-0288508fe93c, name =, id = 3 [0x000 00188] TRACE CStreamDbImpl::DoDeviceBootstrapGetByGuid - In DoDeviceBootstrapGetByGuid for deviceId = 3b5be104-86c3-4862- 8c3a-d4019fa8d5a1 [0x000 00188]TRACECStreamDbImpl::DoDeviceGetByMac - In DoDeviceGetByMac for mac = E27AE23D9F48 [0x000 00188]DEBUGCClientDeviceInstanceDbAccess::DoGetOne - got device record, name = WinXp, mac = E27AE23D9F48 [0x000 00188]DEBUG CDiskLocatorInstanceDbAccess::DoGetByDeviceId - harvested diskLocator info, diskLocatorId = 26fd6469-a761-4d0f- ae65-0288508fe93c, name =, id = 3

29. PVS Logging Continued [0x0000018 8]TRACE CServerInstanceDbAccess::DoChooseLeastBusyServerForDiskLocator - In DoChooseLeastBusyServerForDiskLocator [0x0000018 8]DEBUG CServerInstanceDbAccess::RoundRobinChooseLeastBusyServerForDiskLocator - found at least one leastBusy server, setting minDeviceCount = 0 [0x0000018 8]DEBUG CServerInstanceDbAccess::RoundRobinChooseLeastBusyServerForDiskLocator - harvested leastBusyServer contact info, serverId = f5d9dab3-6f72-42b0-aae7-320f91c837eb, serverName = PVS2KEITH, deviceCount = 0 [0x0000018 8]DEBUG CServerInstanceDbAccess::RoundRobinChooseLeastBusyServerForDiskLocator - choosing the first/only server, numLeastBusyServers = 1, target = 0 [0x0000018 8]DEBUG CServerInstanceDbAccess::RoundRobinChooseLeastBusyServerForDiskLocator - found at least one leastBusy server, setting minDeviceCount = 0 [0x0000018 8]DEBUG CServerInstanceDbAccess::RoundRobinChooseLeastBusyServerForDiskLocator - harvested leastBusyServer contact info, serverId = f5d9dab3-6f72-42b0-aae7-320f91c837eb, serverName = PVS2KEITH, deviceCount = 0

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