Scenario: A Citrix Architect is assessing a Provisioning Services farm. The farm has access to one Store; the vDisks in the Store are shown in the Exhibit.
Click the Exhibit button to view the vDisks.
How much RAM should the architect allocate to each of the Provisioning Services servers to optimally cache existing vDisk data while NOT over-provisioning resources?
To determine the optimal RAM allocation for the Provisioning Services servers, we need to use a baseline formula for RAM sizing that is commonly recommended. The formula is 2GB + (number of vDisks * 2GB) for single-session OS vDisks, such as server operating systems like those listed. Given that there are three vDisks (Windows-Server-2008R2, Windows-Server-2012R2, and Windows-Server-2016) all presumably single-session OS, the calculation would be 2GB + (3 * 2GB) + 15% buffer. This results in a total of approximately 8.7GB, rounded up to the nearest value provided in the options, which is 9GB. However, for multi-session OS vDisks, the calculation would require more RAM, potentially 4GB per vDisk. Given the presence of potentially different formulas from various sources and considerations of buffer, allocating 17GB (option B) is a reasonable choice to ensure optimal performance without over-provisioning resources.
Answer: B A baseline RAM sizing formula to use for testing is 2GB + (XA_vDisk * 4GB) + (XD_vDisk * 2GB) + 15% Buffer = 16.1Gb
What is the source for this formula? I would say D as suggested by @ijhoojhisdojihoij stated.
Correct B, source CWS-415-2I-en-StudentManual-v01.pdf, p.317: Cache in Provisioning Server Memory • Baseline RAM sizing formula to use for testing: • 2GB + (#CVA_vDisk * 4GB) + (#CVD_vDisk * 2GB) + 15% (Buffer) • #CVA_vDisk = number of vDisks for Multi-session OS • #CVD_vDisk = number of vDisks for Single-session OS • This caching type is built into Citrix Provisioning. • Primary design consideration is sizing RAM on the Provisioning Servers based on the type and number of vDisks in the environment. Our vDisks must be server type as said its names)
Answer D is correct. Total Server RAM = 2GB + (# of vdisk * 2 GB) https://docs.citrix.com/en-us/xenapp-and-xendesktop/7-15-ltsr/citrix-vdi-best-practices/design/design-userlayer4.html
The right formula to use: 2 GB + ( CVA_vDisk * 4GB + ( # CVA vDisk * 2GB ). Explanation: CVA_vDisk = number of vDisk for Multi-Session OS. CVA means: Citirx Virtual Apps. Requires: 4 GB RAM for each vDisk. CVD_vDisk = number of vDisk for Single-Session OS. CVD means: Citrix Virtual Desktop. Requires: 2 GB RAM for each vDisk. The questions only thing the question/scenario doesn't mentions. If the vDisks are Single or Multi Session OS. My gues is they use Server-OS. Therefor i go for Citirx Virtual Apps and Multi-Sessions OS. My source is Citirx Training and docs.citirx.com. The right answer would be 3 vDisk with Multi-Session-OS * 4 GB = 12 GB RAM. 2 GB standard. +15% equals 16.1 GB RAM Formula: 2 GB + 3 times a CVD_vDisk * 4GB + 15% = 16.1 GB RAM. Best regards.
Interstingly in the newer version - 715 ltsr which is not new anymore, the formula is differnt as ijhoojhisdojihoij mentioned. So which one is to be used?!
Correct B, source CWS-415-2I-en-StudentManual-v01.pdf, p.317: Cache in Provisioning Server Memory • Baseline RAM sizing formula to use for testing: • 2GB + (#CVA_vDisk * 4GB) + (#CVD_vDisk * 2GB) + 15% (Buffer) • #CVA_vDisk = number of vDisks for Multi-session OS • #CVD_vDisk = number of vDisks for Single-session OS • This caching type is built into Citrix Provisioning. • Primary design consideration is sizing RAM on the Provisioning Servers based on the type and number of vDisks in the environment. Our vDisks must be server type as said its names)