What happens when no free RAM is available with the ‘Cache in device RAM with overflow on hard disk’ write cache option?
What happens when no free RAM is available with the ‘Cache in device RAM with overflow on hard disk’ write cache option?
When no free RAM is available with the ‘Cache in device RAM with overflow on hard disk’ write cache option, the older writes are moved to the overflow disk on the target device. This mechanism ensures that the most recent data remains in the faster RAM cache, while older data that is less likely to be accessed is offloaded to the hard disk for better performance and stability.
“Cache on device RAM with overflow on hard disk represents the newest of the write cache types. Citrix recommends using this cache type for PVS, it combines the best of RAM with the stability of hard disk cache. The cache uses non-paged pool memory for the best performance. When RAM utilization has reached its threshold, the oldest of the RAM cache data will be written to the local hard drive. The local hard disk cache uses a file it creates called vdiskdif.vhdx.” https://support.citrix.com/article/CTX119469
Yes, B. Older writes are moved to the overflow disk on the target device.