In a nutshell…

Marc, I am in agreement with Chris’s point about abstraction of service levels.

What I suggest is that we collectively work toward improving communication between information management and storage applications, just as we need to improve communication between information stewards (business) and custodians (IT). Until then we’ll continue to create systems in which the left hand hasn’t a clue what the right hand is doing.

Didn’t want you to think I forgot about you. I’ll address your response later this week, partly here for those who may be following this thread and more thoroughly on our blog.

Tiering will happen because different data has different SLA requirements. Commonly accessed data will live on flash. Infrequently accessed data will live on cheap disks. Never accessed data will live on spun down disks. Further, the most successful tiering will be automatic and spun down disks will spin up on demand.

Check out Compellent. Been doing that for some time now and getting super high customer sat on the reality of that technology.

I think that Marc did great academic job trying to identify the terms ILM, HSM and tiering and the differences between them.

When it comes to engineering we need to identify our new feature and emphasize our intention that this feature is a function of IOPs, and yes it can help you to save money if you use your resources wisely.

Steve said that he agree with Marc but when it comes to the “real world” sales persons introduce tiering as HSM.

I think the source of the confusion is because generally, unused data or “cold data” requires less IOPs and this is the cross-road between tiering and HSM.

Sales persons not always understand all the technical details and they are generally driven by the new buzzword in market, and maybe they do understand but they don’t really care,as far as it answer the ‘right’ questions:

Can it help the customer to decrease costs, can it helps him to better utilize his resources (or shell I ask , can it helps me to sell the product?) and the answers to all questions is YES.

I would like to quote a joke:
An engineer, a physicist, and a mathematician were on a train heading north, and had just crossed the border into Scotland.
• The engineer looked out of the window and said “Look!
Scottish sheep are black!”
• The physicist said, “No, no. Some Scottish sheep are
black.”
• The mathematician looked irritated. “There is at least
one field, containing at least one sheep, of which at
least one side is black.”
________________________________________
variants:
•The statistician : “It’s not significant. We only know there’s one black sheep”
•The computer ‘scientist’ : “Oh, no! A special case!”

Mark is the mathematician (all in a good spirit)

To make the distinction better Marc said the wonderful sentence:
“Storage tiering can assume all data should be located on lower performance storage until activity levels demand that it be moved to higher performance storage.”

This is the theory, now to reality, do you have free high performance storage (which generally is very expensive) and you don’t use it.

And when it needs to be copied into the high performance storage, what then Marc? How do you identify that activity levels demand it to be moved to higher performance storage? just because at that specific day someone used the data intensively?
You don’t mean to monitor it at real time and copy the data at the background,do you? And what if the user will never use it again is it going to stay at the high performance storage? or copies back to the lower level?

What you are suggesting in that sentence is called cache and what you are actually saying I putting the cache on the high performance storage.

In any way that you look at it: Storage administration needs planning!

Because it is a technical discussion I would like to bring my point of view:
The administrator should locate/manage his storage according to the organization ILM paradigm.
Yes, it has nothing with Storage product, but teh storage products should give him the capability to do so.

I don’t believe that fully automated tiering will be acceptable in the market, people wants to know where the data is located and don’t like that ‘someone’ change the location behind their back (even if it is for good purposes). However, static tiering and semi automated tiering can and should be part of the view.

I will explain:
In the storage world today almost all the players talks about virtualization , user generally create Pools of the same tiering and locate applications and data accordingly.
As a rule of thumb, high transactional DB that hold the core of the buisness will be located at the high performance storage pools – this is what I called Static tiering.
BTW: even if the database taht manage teh “workers gaming zone” requiers better IOPs rate then the DB that manage the core of the buisness , we will still locate the core of the buisness on the higher we have. so it is not all about IOPs.

No one would like that the storage management tool will move data from one pool to another automatically.
Now regarding semi automated tiering:
According to policy based rules the user can define that the storage allocation for snapshots or backups for example, will be automatically taken from Pools which are defined as tier B.
That’s it:
It might be that tiering automation will be acceptable only if it will be marketing as cache level solution (remember teh L1 , L2).
Dror

You seem to think that storage products should also be ILM products. WAKE UP! Storage and ILM are different and people should think hard about how much overlap there should be.

Chris makes the point, “Ultimately, service levels and service catalog should be abstracted from the technology used to deliver them.” I think you agreed with that, but I’m not sure.

The costs of managing storage and managing data are related, but different. The key to running a cost effective operation is understanding which ways to turn the dials for each without screwing up the other. Storage tiering is certainly not for everybody, but it can certainly give IT organizations great options for reducing the cost of storage performance – without impacting ILM goals at all.

NAS inherently has a lot more overlap between storage and ILM than SAN does because NAS manages files, directories and their metadata. It is a lot of lifting – and the way I see it – the biggest strength and weakness of NAS.

What are a few of the things that they want? They want…

* to store information in a way that makes sense to them.
* to hold onto it for as long as they require.
* to preserve and protect not just the information assets, but also any defined relationships between them.
* to find and retrieve it in a way that makes sense to them.
* to retrieve it with speed appropriate to the asset’s importance.
* for it to be usable/viewable/reusable once retrieved. (this is one of the ticking time bombs of storage)
* for the system to “watch their backs” and alert them when something is amiss, out of whack, out of compliance, or at risk.
* to automate that which can be safely automated without fear of failures that might lead to harsh penalties.
* and to do all of this affordably over the lifetime of their assets. (ahhh, the mythical holy grail)

Steve, we know how people operate in the real world once they brush problems under the rug. Out of sight, out of mind. Leave it for the next guy to clean up. Compression (at list intra-file compression) may save space today by brushing the issues under the rug for now, but eventually some other poor schmuck who inherits the mess is going to have to clean it up. And millions of compressed assets MAY make his/her job a lot more difficult and resource intensive.

I prefer to shame the companies into making change sooner rather than later by explaining that the problem is only going to get more expensive as time passes and open them up to even more risk. Sadly, even that strategy can fail. If only their customers knew what goes on behind the scenes.

There’s a reason every single one of my presentations end with a slide that says “Pay me now or pay me later”. Eventually, they all pay the piper.

Chris

Thanks for the response. As far as disagreeing with Marc, well, I guess that is fine, but he hits on some important points. To your point, You are actually making my point. Tiering is a about service levels and who decides these levels? IT? No, lines of business managers do and they can’t agree on anything other than – make my storage costs go down. I spent some time with some of these practitioners this weekend, and the only thing they did agree on was storage is too expensive.

So, in the vane of sounding self serving, compress it all and ALL of this goes away. (Well at least for a few years.)

Thanks again for your comments.

There’s no point in talking about a storage strategy until you understand what’s going on at the business level with information and the way that information is managed, consumed and put out to pasture. Most of the storage types I have met understand bits, bytes, blocks, volumes and LUNs like nobody’s business, but they know VERY little about the way information is created, shared and consumed. Which explains why many of their products have proven to be inefficient or inadequate in the context of modern information management.

I STRONGLY disagree with most of Marc’s response. Hell I don’t even know where to begin explaining my issues with it. I could spend all day writing a detailed response, but I’m not going to bother.

I will write this…

Tiering is about service levels. On that much I would think we would all agree. Understand, however, that there is a direct and inextricable relationship between information stewards (in business) and information custodians (in IT) and the bond is storage real estate. Establishing realistic, sustainable, manageable storage service levels requires collaboration and a knowledge of corporate information assets that goes well beyond monitoring I/O levels in an array.

Should any storage industry pundits wish to debate the topic, I’d love to participate along with some practitioners from the information management side of the house. Any takers?