Caching inside the host
Originally written by
- Others (sometimes - the same people) attempt to put the cache inside the
- Full use of the low-latency of SSD storage.
- Allows doing the caching at the file-system level.
- No flexibility in assigning SSD space to servers - needs careful
planning and on-going management.
- PCI-e SSDs (which are faster then SAS SSDs) are not hot-swappable -
any need for upgrade means downtime.
- Not manageable without proper software support (e.g. the storage
snapshots won't include data freshly written to the SSD cache).
- Requires a whole new software stack to really become useful.
- Example: EMC's VFCache ("project lightning"): http://www.emc.com/about/news/press/2012/20120206-01.htm