Is there a lot disparity between flash caching software products available today? For example, how does flash caching software from companies like Velobit and Nevex compare to flash cache products from major storage vendors like EMC and NetApp?
Yes, there are huge differences. The majority of caching software is block-based (such as Velobit), meaning it is used with SAN storage. It caches blocks based on an algorithm. That algorithm can be based on frequency of access where it puts the data into the cache when it meets certain frequency levels and takes it out when those levels drop.
Some algorithms are based on data age. New data is always placed in the cache. As it ages, it's purged. Some caching software even allows specific data to be "pinned" in the cache so that it is always there. The only file-level caching software is Nevex (recently acquired by Intel).
Dig Deeper on Flash storage for applications
Related Q&A from Marc Staimer
Network File System and Common Internet File System/Server Message Block were designed to work with any operating system, but NFS remains dominant in... Continue Reading
Object storage has unique features, including erasure coding and multi-copy mirroring, which may make it better suited to data protection than more ... Continue Reading
Why would you attach NAND flash storage directly to the memory channel? Isn't RAM much faster than NAND? Marc Staimer discusses this and more in this... Continue Reading