Tag Archives: Dell Compellent

Data Deduplication – Dell is first and last

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A very interesting report surfaced in front of me today. It is Information Week’s IT Pro ranking of Data Deduplication vendors, just made available a few weeks ago, and it is the overview of the dedupe market so far.

It surveyed over 400 IT professionals from various industries with companies ranging from less than 50 employees to over 10,000 employees and revenues of less than USD5 million to USD1 billion. Overall, it had a good mix of respondents. But the results were quite interesting.

It surveyed 2 segments

  1. Overall performance – product reliability, product performance, acquisition costs, operations costs etc.
  2. Technical features – replication, VTL, encryption, iSCSI and FCoE support etc.

When I saw the results (shown below), surprise, surprise! Here’s the overall performance survey chart:

Dell/Compellent scored the highest in this survey while EMC/Data Domain ranked the lowest. However, the difference between the first place and the last place vendor is only 4%, and this is to suggest that EMC/Data Domain was about just as good as the Dell/Compellent solution, but it scored poorly in the areas that matters most to the customer. In fact, as we drill down into the requirements of the overall performance one-by-one, as shown below,

there is little difference among the 7 vendors.

However, when it comes to Technical Features, Dell/Compellent is ranked last, the complete opposite. As you can see from the survey chart below, IBM ProtecTier, NetApp and HP are all ranked #1.

The details, as per the technical requirements of the customers, are shown below:

These figures show that the competition between the vendors is very, very stiff, with little edge difference from one to another. But what I was more interested were the following findings, because these figures tell a story.

In the survey, only 34% of the respondents say they have implemented some data deduplication solutions, while the rest are evaluating and plan to evaluation. This means that the overall market is not saturated and there is still a window of opportunity for the vendors. However, the speed of the a maturing data deduplication market, from early adopters perhaps 4-5 years ago to overall market adoption, surprised many, because the storage industry tend to be a bit less trendy than most areas of IT. With the way the rate of data deduplication is going, it will be very much a standard feature of all storage vendors in the very near future.

The second figures that is probably not-so-surprising is, for most of the customers who have already implemented the data deduplication solution, almost 99% are satisfied or somewhat satisfied with their solutions. Therefore, the likelihood of these customer switching vendors and replacing their gear is very low, perhaps partly because of the reliability of the solution as well as those products performing as they should.

The Information Week’s IT Pro survey probably reflected well of where the deduplication market is going and there isn’t much difference in terms of technical and technology features from vendor to vendor. Customer will have to choose beyond the usual technology pitch, and look for other (and perhaps more important) subtleties such as customer service, price and flexibility of doing business with. EMC/Data Domain, being king-of-the-hill, has not been the best of vendor when it comes to price, quality of post-sales support and service innovation. Let’s hope they are not like the EMC sales folks of the past, carrying the “Take it or leave it” tag when they develop their relationship with their future customers. And it will not help if word-of-mouth goes around the industry about EMC’s arrogance of their dominance. It may not be true, and let’s hope it is not true because the EMC of today has changed plenty compared to the Symmetrix days. EMC/Data Domain is now part of their Backup Recovery Service (BRS) team, and I have good friends there at EMC Malaysia and Singapore. They are good guys but remember guys, customer is still king!

Dell, new with their acquisition of Compellent and Ocarina Networks, seems very eager to win the business and kudos to them as well. In fact, I heard from a little birdie that Dell is “giving away” several units of Compellents to selected customers in Malaysia. I did not and cannot ascertain if this is true or not but if it is, that’s what I call thinking-out-of-the-box, given Dell as a late comer into the storage game. Well done!

One thing to note is that the survey took in 17 vendors, including Exagrid, Falconstor, Quantum, Sepaton and so on, but only the top-7 shown in the charts qualified.

In the end, I believe the deduplication vendors had better scramble to grab as much as they can in the coming months, because this market will be going, going, gone pretty soon with nothing much to grab after that, unless there is a disruptive innovation to the deduplication technology

Storage Tiering – Responsible and Prudent

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Does your IT have bottomless budget? If not, storage tiering is likely to be considered as one of IT’s weapons to combat the ever growing need for storage capacity.

Storage tiering is not new and in the past, features such as HSM (Hierarchical Storage Management) and ILM (Information Lifecycle Management) addresses storage tiering in different capacities, ranging for simple aging files movement and migration, to data objects being moved within the data infrastructure of an organization with some kind of workflow and searching capabilities.

Lately, storage tiering, and especially automated storage tiering, has been gaining prominence, thanks to the 2 high profile acquisitions – HP 3PAR and Dell Compellent. According to Wikibon,

Tiered storage is a system of assigning applications to different
types of storage media based on application requirements. Factors
considered in the allocation of storage type include the level of
protection needed, performance requirements, speed of recovery,
and many other considerations.Since assigning application data to
specific media may be complex, some vendors provide software for
automatically managing the process.

For the sake of simplicity, this blog talks about automated storage tiering within the storage array itself, where different data blocks are moved within several tiers to achieve just-right storage provisioning. Why do we need to achieve this “just-right provisioning”? Rather than discussing this from an IT, technical angle, the just-right storage provisioning should be addressed from a business and operational angle, and more rightly so, costs and benefits.

Business and operations are about managing costs and increasing profits. In the past, many storage administrators employ a single storage tier architecture. Using the same type of disks, for example, 146G 10,000RPM Fibre Channel disks, there was usually 1 or 2 RAID levels for the entire data storage requirement. Usually RAID 1+0 volumes/LUNs are for the applications that require the highest performance and availability but they come with a big cost. So, the rest of the data are kept in RAID-5 volumes/LUNs. The introduction of enterprise SATA hard disk drives basically changed the rules of the ball game, giving storage administrators another option, a cheaper alternative to store their data. Obviously, storage vendors saw the great need to address this requirement, and hence created automated storage tiering as part of their offerings.

There are quite a few storage solutions that offers the storage tiering feature, and most of them are automated as well, meaning that the data blocks are moved between the different tiers of storage within the array itself automatically. 3PAR, long before they were acquired by HP, had their Dynamic Autonomic Tiering. Today, with HP, 3PAR offers 2 key strengths in their Autonomic Tiering offering.

  • Adaptive Optimization
  • Dynamic Optimization

As HP puts it,

 

Not to be outdone, Compellent (also long before its acquisition by Dell) had the Data Progression feature as part of the Automated Storage Tiering offering. In a nutshell, their solution (which is basically similar from a 10,000 feet view with most of the competitors) is shown below.

 

The idea is to put the most frequently accessed data blocks to the most expensive, fastest, storage tier and then dynamically move the lesser accessed data block to the least expensive, most economical tier.

I have had the privilege to learn more about Compellent (before Dell) technology about 2.5 years ago, thanks to my friends Chyr and Winston, the bosses at Impact Business Solutions. And what Compellent has was pretty cool stuff and I would like to share what I have picked up about Dell Compellent storage solution. But some of the information could be a little out of date.

The foundation of Dell Compellent automated storage tiering feature, called Data Progression, is their Dynamic Block Architecture (as shown below)

 

From a high level, all data blocks are bunched together into a logical data structure called a page. A page is by default 2MB but can be configured between 512KB and 4MB. The page is the granular unit required to initiate and implement the Data Progression feature in Compellent’s automated storage tiering solution. Every page comes with attached metadata about the page such as

  • When was this page created
  • When was this page last accessed
  • Which RAID level is it currently in (RAID 1+0, RAID-59, RAID-55 and so on)
  • Which Tier does it currently reside (Tier 1, 2 or 3)
  • Which kind of disk track does it live in (Fast or Standard)

Meanwhile, there are different storage Tiers and notably, Tier 1, 2 or 3 where different disk profiles reside. Typically, the SSDs or the 15K RPM disk drives will be in Tier 1, the 10K RPM disk drives will be in Tier 2 and the slowest 7200 RPM disks will be in Tier 3.  Each of the 3 tiers are further divided into the outer Fast disk cylinders (where the platters spin the fastest) and the Standard disk cylinders (running in the inner tracks and slower).

As data chunks or blocks are accessed, their frequency of access and their data movement statistics are gathered in real-time, giving the Compellent solution a fairly good intelligence of how the pages should be laid out on the most relevant tiers. As the pages become more stale, and less relevant, the pages of data chunks are progressively relegated to the lower tiers, while the more active, and most relevant pages relative to importance of access, is progressively promoted to the higher tiers.

Different policies can also be configured to ensure that some important pages stay where they are regardless of their frequency of access or their relevance.

There is a very nice whitepaper from Dell detailing their Data Progression technology.

Another big automated storage tiering player is HP 3PAR. I admit that I don’t know the inner details of the HP 3PAR Dynamic Tiering solution, though I had some glossy lessons from a 3PAR Systems Engineer called Nathan Boeger (thanks to my friends at PTC Singapore, the 3PAR distributor back then) about the same time I learned about Dell Compellent. I hope HP can offer to introduce more in depth of how the 3PAR technology works, now that I have gotten cosy with some of the HP Malaysia’s folks.

Similarly, the other big boys are offering the automated storage tiering solution as well. IBM has been offering Easy Tier for almost 18 months and EMC has its FAST2 for about the same time.

Funnily, the odd one out in this automated storage tiering game is NetApp. I was in a partner conference call about 1 year ago and there were questions asking NetApp about their views of automated storage tiering. At that time of the concall, NetApp did not believe in automated storage tiering, preferring to market their FlashCache PCIe (previously called the PAM card) solution. Take note that the FlashCache is a Read-Only “extension” to their NVRAM, and used to accelerate read operations of WAFL. And also take note that NetApp, at the time of writing, does not have an “engine” that performs automated storage tiering, regardless of how they spin it.

There are also host-based file tiering solutions as well.Since I am familiar with the NetApp universe, Arkivio and Enigma Data Solutions are 2 of the main partners that NetApp works with. Recently NetApp also resells StorNext from Quantum. But note that these host-based solutions are file-based, making them less granular, less dynamic and less efficient. They are usually marketed as file archiving solutions, and the host-based license are usually charged by per TB. In large enterprises, this might make sense but for the everyday Joes (with tight IT budgets), host-based file archiving solutions are expensive. And it is nowhere close to the efficiencies of automated storage tiering.

Overall, automated storage tiering, when applied, should help the IT operations and the organization’s business reduce costs. There is no longer a one-size-fit-all model and associating the right storage tier to the relevance and importance of the data at a very granular sub-LUN/sub-volume level will help any organization define a more prudent approach in managing their data actively and more importantly their cost of operations.

This is called Responsible IT. 😀