According to Dell best practices, what is the maximum percentage of physical RAM that should be allocated for the hash and file caches combined?

According to Dell best practices for Avamar client performance tuning, the combined memory allocation for the file cache (--filecachemax) and the hash cache (--hashcachemax) should not exceed 25% of the client machine's total physical RAM. These caches improve performance by keeping file metadata and data chunk hashes in memory, reducing disk I/O. Adhering to the 25% limit ensures that the backup process does not consume excessive memory, which could negatively impact the performance of the operating system and other applications running on the client.

A. 15% is lower than the recommended maximum and may not provide optimal backup performance for clients with many files.
C. 30% exceeds the recommended best practice limit and increases the risk of starving the client's operating system of necessary memory.
D. 40% is significantly higher than the recommended maximum and could lead to severe performance degradation or instability on the client machine.

1. Dell EMC Avamar 7.5 Administration Guide, Page 630, "Client cache tuning." The guide states, "As a best practice, the combined size of the file and hash caches should not exceed 25% of the physical RAM on the client."

2. Dell EMC Avamar Client for Windows User Guide (Multiple Versions), Section on "Performance considerations." This guidance is consistently provided as a key tuning parameter for optimizing client-side performance.

3. Dell EMC Avamar Technical Note: "EMC Avamar Windows Client Performance Best Practices," Page 10, "Cache Tuning." This document explicitly provides the 25% recommendation.