What’s new in 7.18
Version 7.18 of the Linux VDA includes the following new features and enhancements:
DTLS encryption for secure user sessions
Previously available as an experimental feature, DTLS encryption is a fully supported feature in this release. For more information, see Secure user sessions using DTLS.
Pass-through authentication by using smart cards
Users can use a smart card connected to the client device for authentication when logging on to a Linux virtual desktop session. Users can also use the smart card within the session. Use cases include adding a digital signature to a document, encrypting or decrypting an email, or authenticating to a website that requires smart card authentication. For more information, see Pass-through authentication by using smart cards.
This feature is available starting with the 7.17 release. From the 7.18 release, more smart cards are supported, such as PIVKey C910 PKI and Gemalto Instant IP10 smart cards.
Support for Citrix Machine Creation Services
Starting with the 7.18 release, you can use Citrix Machine Creation Services (MCS) to create Linux VMs. For more information, see Use MCS to create Linux VMs.
Support for Federated Authentication Service
The Citrix Federated Authentication Service is a privileged component designed to integrate with Active Directory Certificate Services. It dynamically issues certificates for users, allowing them to log on to an Active Directory environment as if they had a smart card. This allows StoreFront to use a broader range of authentication options, such as Security Assertion Markup Language (SAML) assertions. For more information, see Federated Authentication Service.
Client IME user interface synchronization
To date, the client IME user interface (including the composition window and candidate window) was positioned in the upper left corner of the screen. It did not follow the cursor and sometimes was located far from the cursor in the text input area. Starting with this release, Citrix enhances usability and further improves the seamless experience with the client IME. For more information, see Client IME user interface synchronization.
Support for H.265 video codec
The Linux VDA now supports the H.265 video codec for hardware acceleration of remote graphics and videos. You can use this feature on Citrix Receiver for Windows 4.10 and later. To benefit from this feature, enable it on both the Linux VDA and on Citrix Receiver. If the GPU at the endpoint does not support H.265 decoding using the DXVA interface, the H.265 Decoding for graphics policy setting is ignored and the session falls back to using the H.264 video codec. For more information, see H.265 video encoding and Configure graphics.
Selective use of the H.264 video codec to compress graphics
This feature enables HDX Thinwire to detect and encode parts of the screen that are frequently updated using the H.264 video codec, for example, video content. Still image compression (JPEG, RLE) and bitmap caching continue to be used for the rest of the screen, including text and photographic imagery. Users get the benefit of lower bandwidth and better quality for video content combined with lossless text or high quality imagery elsewhere. To enable this feature, change the policy setting Use video codec for compression to Use when preferred (default) or For actively changing regions. For more information, see Graphics policy settings and Configure graphics.
Use H.264 for Build to Lossless in Thinwire
By default, the Build to Lossless preference of the Visual quality policy setting is now H.264 instead of JPEG for moving images. H.264 encoding offers superior image quality. The Use video codec for compression policy controls that preference, with the default being Use when preferred. To force Build to Lossless to use JPEG, set the Use video codec for compression policy to Do not use video codec. If Citrix Receiver does not support Selective H.264, Build to Lossless falls back to JPEG regardless of the policy settings. Citrix Receiver for Windows 4.9 and Citrix Receiver for Linux 13.5 and later support Selective H.264. For more information about the Visual quality and Use video codec for compression policy settings, see Visual display policy settings and Graphics policy settings.
Thinwire progressive display
This release introduces a progressive update mode to help improve screen interactivity in poor network scenarios. When low bandwidth (<2 Mbps) or high latency (> 200 ms) conditions are detected, images are heavily compressed and text quality is reduced. The quality gradually builds to lossless after user activity ceases. For more information, see Thinwire progressive display.
Enhanced HDX 3D Pro for multi-monitor sessions
Previously, hardware encoding by using NVIDIA cards could support only a limited number of monitors with the overall resolution not to exceed 4096 x 4096. This release introduces an experimental feature to resolve this limitation.
The xdlcollect script integrated into the Linux VDA software
The xdlcollect Bash script is used to collect logs. Previously, you had to download, unzip, and copy the script to the desired Linux VDA. For more information, see the Knowledge Center article CTX202252.
Starting with the 7.18 release, xdlcollect is integrated into the Linux VDA software and located under /opt/Citrix/VDA/bin. After yon install the Linux VDA, you can run the bash /opt/Citrix/VDA/bin/xdlcollect.sh command to collect logs. After log collection completes, a compressed log file is generated in the same folder as the script. Xdlcollect can ask you whether or not to upload the compressed log file to Citrix Insight Services (CIS). If you agree, xdlcollect returns an upload_id after the upload completes. The upload does not remove the compressed log file from your local machine. Other users can use the upload_id to access the log file in CIS.
System requirement changes
- In this release, RHEL 7.4 and CentOS 7.4 are supported while RHEL 7.3 and CentOS 7.3 are not. For more information, see System requirements.
- To prevent your software packages from updating to the corresponding versions in RHEL 7.5, run the echo ‘7.4’ > /etc/yum/vars/releasever command on the Linux VDA.