Merge pull request #292567 from flang-msft/fxl---Update-memory-reservation-docs--ado--30324187

fxl---Updated with numbers from engineering

Author: prmerger-automator[bot]

articles/azure-cache-for-redis/cache-best-practices-memory-management.md

@@ -37,7 +37,7 @@ Configure your [maxmemory-reserved setting](cache-configure.md#memory-policies)
 
 - The `maxfragmentationmemory-reserved` setting configures the amount of memory, in MB per instance in a cluster, that is reserved to accommodate for memory fragmentation. When you set this value, the Redis server experience is more consistent when the cache is full or close to full and the fragmentation ratio is high. When memory is reserved for such operations, it's unavailable for storage of cached data. The allowed range for `maxfragmentationmemory-reserved` is 10% - 60% of `maxmemory`. If you try to set these values lower than 10% or higher than 60%, they are re-evaluated and set to the 10% minimum and 60% maximum. The values are rendered in megabytes.
 
-- One thing to consider when choosing a new memory reservation value (`maxmemory-reserved` or `maxfragmentationmemory-reserved`) is how this change might affect a cache with large amounts of data in it that is already running. For instance, if you have a 53-GB cache with 49 GB of data and then change the reservation value to 8 GB, the max available memory for the system will drop to 45 GB. If either your current `used_memory` or your `used_memory_rss` values are higher than the new limit of 45 GB, then the system must evict data until both `used_memory` and `used_memory_rss` are below 45 GB. Eviction can increase server load and memory fragmentation. For more information on cache metrics such as `used_memory` and `used_memory_rss`, see [Create your own metrics](monitor-cache.md#create-your-own-metrics).
+- One thing to consider when choosing a memory reservation value (`maxmemory-reserved` or `maxfragmentationmemory-reserved`) is how this change might affect a cache with large amounts of data in it that is already running. For instance, if you have a 53-GB cache with with the reserved values set to the minimum of 10 GB, the max available memory for the system is approximately 42 GB. If either your current `used_memory` or your `used_memory_rss` values are higher than the limit of 42 GB, then the system must evict data until both `used_memory` and `used_memory_rss` are below 42 GB. Eviction can increase server load and memory fragmentation. For more information on cache metrics such as `used_memory` and `used_memory_rss`, see [Create your own metrics](monitor-cache.md#create-your-own-metrics).
 
 > [!NOTE]
 > When you scale a cache up or down, both `maxmemory-reserved` and `maxfragmentationmemory-reserved` settings automatically scale in proportion to the cache size. For example, if `maxmemory-reserved` is set to 3 GB on a 6-GB cache, and you scale to 12-GB cache, the settings automatically get updated to 6 GB during scaling. When you scale down, the reverse happens.