The Linux VDA streaming feature is provided as a technical preview at this release of Provisioning Services. Citrix recommends that use of this feature be limited to non-production environments.
To install the Linux Streaming feature, you must be logged in as an administrator. When installing, consider that the following commands must be issued in a root shell, or with sudo privileges.
Consider the following when using this feature:
- Ensure that the time stamp on the PVS server and the golden image match.
- If you enable RAM cache for the Linux device, set the cache size to 8MB (the minimum value). Linux uses as much RAM as necessary, including all available memory, for the write cache. The amount specified in the console is the amount reserved up front; Citrix recommends that you reserve as little as posssible, which effectively allows Linux to manage memory usage.
- The target device name in the PVS imager UI typically defaults to im_localhost which must be changed if you create more than one vDisk. Note that using the same target device name could cause the PVS imager command to fail.
- Installation (and subsequent updates) must be done in super user mode. There are two ways to accomplish this:
- Enter user mode in a terminal using the su command. You must do this once for a terminal session.
- Enter sudo before the command. For example, sudo yum install tdb-tools; do this for every command.
- Linux is case sensitive.
- After booting a Linux target device, a warning message may appear indicating a SE Linux Alert Browser.
SELinux is not supported on streaming Linux targets.
For RedHat/CentOS distributions:
yum --nogpgcheck localinstall pvs_RED_HAT_<package version>.rpm
Installation is accomplished using a GUI or through the command line. To use the GUI, you must install PyQT4 using your preferred method for installing 3rd party Python modules.
Refer to the Python Wiki for more information on PyQT4 bindings.
Creating self-signed certificate for streaming PVS Linux target devices
When using the Linux Streaming feature, consider that the link from a Linux target device to the PVS Soap server uses a SSL connection which requires that you configure an X.509 Certificate on the Soap server. The certificate’s CA certificate must also be present on the PVS server and the Linux target device.
Use the information in this section to access the configuration wizard for selecting the appropriate certificate used for the connection.
The CA and X.509 certificate can be created on Windows using the makecert command.
To create a self-signed certificate for Linux VDA streaming:
1. Download and install the Windows SDK for your PVS Server operating system.
2. Open a command prompt and navigate to the bin folder of the SDK. By default: C:\Program Files (x86)\Windows Kits\SDK_Version\bin\x64>.
3. Run the following commands:
makecert -n "CN=PVSRootCA" -r -sv PVSRootCA.pvk PVSRootCA.cer
makecert -sk PVSSoap -iv PVSRootCA.pvk -n "CN=FQDN of the PVS Server" -ic PVSRootCA.cer -sr localMachine -ss my -sky exchange -pe
4. Install the PVS console and PVS server.
5. Run configuration wizard. On the Soap SSL Configuration page, optionally select the certificate created:
When the Soap SSL Configuration screen first loads the certificate is highlighted (in grey) which gives the appearance that it is selected. Ensure that the certiticate is selected; it should turn blue to indicate that it has been chosen.
6. Finish the configuration wizard to create the PVS farm.
Using the GUI to create a Linux golden image
To invoke the GUI to install this feature:
- Log in as an administrator.
- Execute the following:
If the pvs-imager command fails due to a hostame issue, verify that your network configuration is correct. The system's hostname should not be set to localhost.
After executing the command, the UI screen appears:
Using the CLI to install the Linux streaming feature
To invoke the command line to install this feature:
- Log in as an administrator.
- Execute the following command:
The command line installation includes two options:
- -C allows you to create a new vDisk
- -U allows you to update an existing vDisk
The image below illustrates non-GUI related installation options for the Linux Streaming feature:
Supported file systems for imaging are ext4, xfs, or btrfs.
Log files related to PVS can be found in /run/pvs/pvsvdd.log.
If you are not using the XenDesktop Setup Wizard, in order to use hard disk caching or hard disk overflow caching, the target device must have a disk with a formatted partition with the label ‘PVS_Cache.’ This object can be created by using the mkfs –L ‘PVS_Cache’ command on the target device. Any case sensitive file system can be used for the cache, but XFS is recommended.
An administrator can create any cache disk selection logic for their environment by writing a bash script that runs at boot time. The script would look for a cache device candidate by whatever mechanism is best suited to the environment, running mkfs on it, and rebooting.