SSD as a cache

Content Software for File User Guide

Part Number

Recently accessed or modified data is stored on SSDs, and most read operations are of such data and served from SSDs. This is based on a single, significant LRU clearing policy for the cache that ensures optimal read performance.

Note: On a tiered filesystem, the total capacity determines the maximum capacity that can be used to store data. It could be that all data reside in the object store due to the SSD uses above and the time-based policies below.

For instance, consider a 100 TB filesystem (total capacity) with a 10 TB SSD capacity for this filesystem. All the data reside in the object store; no new writing is allowed. However, the SSD space is only partially used (until files are deleted or the filesystem's total size is increased), leaving the SSD for metadata and cache only.