Another of the companies that presented at Tech Field Day was Avere Systems, a startup from Pittsburgh focussing on optimized storage tiering. After spending a good chunk of time with NetApp, another approach to storage was somewhat refreshing. Avere uses an appliance to handle the storage tiering and optimization before the data is stored. If you don’t write the extra bits to a disk, there is no dedupe or manage extra data.
Tiering or Caching… that appears to be one of the questions
Some storage vendors use a flash cache (which should be spelled flache cache in the spirit of things, but oh well) to ensure that performance and decent (or blazingly fast) IOps occur. This approach is fine because hot, or frequently accessed, data is kept in the cache for speedier access.
Other strategies involve tiering, or storing less needed data on slower and cheaper disks while keeping the hot and very active data on solid state disks or other much faster disks to allow for fast access to these items. I am not sure which approach is best (or nearest perfect) because it seems each method has an issue the other one claims to solve. The Great Taste/Less Filling approach to storage if you will.
If a cache made of primarily SSD media allows data that is frequently accessed to be stored in a way that makes access to it much faster than other, less frequently accessed data, someone (or some algorithm) has to be able to decide by some reasonable method which data is “hot”.
On the other hand, a tiered system uses algorithms to decide which data is hot and which data is cold also, but moves this data between tiers of spindle/disk types as it becomes more frequently used.
Where does Avere fit into this picture?
Right out front. Avere provides an appliance that makes the tiering decisions for the stored data before it ever gets stored, then writes it to the disk. When the information is needed, the appliance gets the information and caches a copy of the data to ensure immediate response and delivery to the users or machines needing the data.
This is a benefit because the appliance out front is handling the caching and tiering, keeping the cost of the mass storage down and allowing great response times when reading and writing information.
More than just storage aiding devices
When I watched the presentation that Ron gave at Tech Field Day, I was quite impressed with his enthusiasm for the things his company is working on. Explaining why storage is constantly growing and the disk performance is not keeping up with the needs of organizations was a particularly interesting portion of this presentation. Because disk speeds (in IOPS) arent keeping up with user requirements (or organizational requirements) of immediate data access, IT departments would typically have to throw more disks at the problem to improve performance. This happens because the more spindles you have available to handle your data, the better performance you can achieve.
Many storage vendors sell more disks to improve the performance of storage, but because Avere uses an appliance containing its own file system and decide which data should be sent to which section (or tier) the storage array simply serves up disk for the Avere appliance to send data toward. This allows the back end storage to be commodity, moderate performance spindles which come at a cheaper price.
When a user requests a file, the Avere appliance caches a copy of that file pulled from the storage array and serves it to the user. Multiple requests are served from the front end and the information is only written back to storage on an as needed, but regular basis.
If there are multiple locations, additional appliances can be added to improve the performance for the users against stored data and to allow items to be striped across multiple avere appliances, improving failover for the users as well as overall performance.
Scaling… does it scale?
The Avere approach scales in both directions (out and up) because you can add more spindles to provide storage depth in addition to adding more avere appliances to scale out and provide breadth of storage and greater accessibility and speed of access to users across your environment.
I am certainly interested in testing this appliance in a real environment and will be working with Avere to see if this is possible. Because storage is coming soon to my organization, it might be a great time to do some testing (and of course more blogging and digging into how things work where allowed).
