Tuesday, March 30, 2010

Not-so-Autonomic Storage Tiering

Autonomic is a word that is increasing being used to describe the ultimate in ease of use of data storage equipment with “autonomic tiering” having recently come into vogue. However, despite there being a plethora of tiering solutions available not all of them are as autonomic as they claim.

My first recollection of the use of the word in an IT context was IBM’s Self-Managing Autonomic Technology which they describe as enabling a fluid response to change like having the ability to manage themselves and dynamically adapt to change such as identifying and correcting problems often before they are noticed by IT personnel. In the context of a tiered storage solution this means the transparent movement of data between tiers with little or no human intervention.

To the purist (read non-marketer) many of the big name solutions lack the ability to perform truly autonomic data movement. Though they have the ability to move data programmatically or via a policy based process according to a data classification which is certainly a large step forward in the quest to optimize a storage environment, they cannot transparently (autonomically) move that data to the appropriate tier. In short they have not eliminated much of the management complexity that commonly accompanies tiered storage management.

These not-so-autonomic solutions require the administrator to define a policy as to when data should be moved (batch processing). If this policy based approach sounds eerily similar to the traditional HSM's of the past you are in good company. The value of an autonomic solution lies in its ability to be proactive instead of reactive. Without the power to perform data movement in conjunction with real time access patterns, a solution becomes purely reactive.

When an administrator is forced to make a best guess as to the most advantageous time to move data from Tier 1 to Tier 0, the placement of aged data is inevitable. This aged data may not be relevant to current access demands leading to cache misses, and latency issues. It is true that data with a predictable access pattern can be pre-loaded and available on SSD when required but this is far from autonomic.

These less than autonomic companies will tell customer that by requiring policy based batch processing, they are really giving administrators much needed control over their environment. The opinion of at least one company Atrato Inc, is that administrators should have the choice as to whether data should be manually or autonomically managed on an application/LUN specific basis. With data centers expanding into the petabytes, the storage model simply cannot support the do-it-yourself approach. Intelligent, transparent movement is, after all, the whole point of implementing a so called "autonomic solution".

The following list is of companies that offer a flavor of tiered storage management. It is not intended to be an exclusive list by any definition simply a sample. Atrato Inc, HP, EMC, Compellent, 3PAR, HDS, BluArc, and Avere.


Anonymous said...
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TT said...

Having worked in the storage industry since 1979, I've heard the word "automomic" many times. From my understanding of 3PAR's implementation, it is autonomic. Having said that, Atrato appears to be making some exciting head-way into this space. I also expect IBM to use the automomic word as they go sub-Lun - and of course they have a long history of sub-volume management with Data Set placement and management on zOS. Could they cross the chasm and bring that wealth of knowledge and experience into the sub-Lun management arena? Could be.

BillM said...

Anonymous: Thanks for your comment. Obviously are a 3PAR employee, my regards to my friends at 3PAR.

Just a couple of points. Do a bit digging on competitive products and you will see the use of autonomic pre-dates the 3PAR announcement. Not a big issue but as you claimed the first mover position I felt obligated to correct.

I take nothing away from the cleverness of the 3PAR’s Adaptive Optimization software implementation; it is impressive and certainly appears to be leading many of the currently available offerings. However what I have gleaned from my reading is that it does require intervention by the administrator to establish the customizable policies that will then automatically rebalance workloads across storage tiers. Apparently there is also the selection of QoS gradients that determines when specific data is moved, another administrator task. These requirements would I suggest disqualify or at least put in serious question the use of the word autonomic.

BillM said...

TT: Thanks for your comments. I agree that it is only a matter of time before IBM applies their wealth of autonomic expertise to their storage solutions. However it is not guarenteed.

Joshua Smith said...

For businesses it needs to stay updated by using actual software applications. Some solutions could be developed by outsourced company that provides Microsoft .Net development for business companies.

Joshua Smith said...
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