Chink in NetApp MetroCluster?

Ok, let me clear the air about the word “Chink” (before I get into trouble), which is not racially offensive unlike the news about ESPN having to fire 2 of their employees for using the word “Chink” on Jeremy Lin.  According to my dictionary (Collins COBUILD), chink is a very narrow crack or opening on a surface and I don’t really know the derogatory meaning of “chink” other than the one in my dictionary.

I have been doing a spot of work for a friend who has just recently proposed NetApp MetroCluster. When I was at NetApp many years ago, I did not have a chance to get to know more about the solution, but I do know of its capability. After 6 years away, coming back to do a bit of NetApp was fun for me, because I was always very comfortable with the NetApp technology. But NetApp MetroCluster, and in this opportunity, NetApp Fabric MetroCluster presented me an opportunity to get closer to the technology.

I have no doubt in my mind, this is one of the highest available storage solutions in the market, and NetApp is not modest about beating its own drums. It touts “No SPOF (Single Point of Failure“, and rightly so, because it has put in all the right plugs for all the points that can fail.

NetApp Fabric MetroCluster is a continuous availability solution that stretches over 100km. It is basically a NetApp Cluster with mirrored storage but with half of  its infrastructure mirror being linked very far apart, over Fibre Channel components and dark fiber. Here’s a diagram of how NetApp Fabric Metrocluster works for a VMware FT (Fault Tolerant) environment.

There’s a lot of simplicity in the design, because when I started explaining it to the prospect, I was amazed how easy it was to articulate about it, without all the fancy technical jargons or fuzz. I just said … “imagine a typical cluster, with an interconnect heartbeat, and the storage are mirrored. Then imagine the 2 halves are being pulled very far apart … That’s NetApp Fabric MetroCluster”. It was simply blissful.

But then there were a lot of FUDs (fear, uncertainty, doubt) thrown in by the competitor, feeding the prospect with plenty of ammunition. Yes, I agree with some of the limitations, such as no SATA support for now. But then again, there is no perfect storage solution. In fact, Chris Mellor of The Register wrote about God’s box, the perfect storage, but to get to that level, be prepared to spend lots and lots of money! Furthermore, once you fix one limitation or bottleneck in one part of the storage, it introduces a few more challenges here and there. It’s never ending!

Side note: The conversation triggered the team to check with NetApp for SATA support in Fabric MetroCluster. Yes, it is already supported in ONTAP 8.1 and the present version is 8.1RC3. Yes, SATA support will be here soon. 

More FUDs as we went along and when I was doing my research, some HP storage guys on the web were hitting at NetApp MetroCluster. Poor HP! If you do a search of NetApp MetroCluster, I am sure you will come across these 2 HP blogs in 2010, deriding the MetroCluster solution. Check out this and the followup on the first blog. What these guys chose to do was to break the MetroCluster apart into 2 single controllers after a network failure, and attack it from that level.

Yes, when you break up the halves, it is basically a NetApp system with several single point of failure (SPOF). But then again, who isn’t? Almost every vendor’s storage will have some SPOFs when you break the mirror.

Well, I can tell you is, the weakness of NetApp MetroCluster is, it’s not continuous data protection (CDP). Once your applications have written garbage on one volume, the garbage is reflected on the mirrored volume. You can’t roll back and you live with the data corruption. That is why storage vendors, including NetApp, offer snapshots – point-in-time copies where you can roll back to the point before the data corruption occurred. That is why CDP gives the complete granularity of recovery in every write I/O and that’s something NetApp does not have. That’s NetApp’s MetroCluster weakness.

But CDP is aimed towards data recovery, NOT data availability. It is focused on customers’ whose requirements are ability to get the data back to some usable state or form after the event of a disaster (big or small), while the MetroCluster solution is focused on having the data available all the time. They are 2 different set of requirements. So, it depends on what the customer’s requirement is.

Then again, come to think of it, NetApp has no CDP technology of their own … isn’t it?

Falconstor – soaring to 7th heaven

I was invited to Falconstor version 7.0 launch to the media this morning at Sunway Resort Hotel.

I must admit that I am a fan of Falconstor from a business perspective because they have nifty solutions. Many big boys OEMed Falconstor’s VTL solutions such as EMC with its CDL (CLARiiON Disk Library) and Sun Microsystems virtual tape library solutions. Things have been changing. There are still OEM partnerships with HDS (with Falconstor VTL and FDS solutions), HP (with Falconstor NSS solution) and a few others, but Falconstor has been taking up a more aggressive stance with their new business model. They are definitely more direct with their approach and hence, it is high time we in the industry recognize Falconstor’s prowess.

The launch today is Falconstor version 7.0 suite of data recovery and storage enhancement solutions. Note that while the topic of their solutions were on data protection, I used data recovery, simply because the true objective of their solutions are on data recovery, doing what matters most to business – RECOVERY.

Falconstor version 7.0 family of products is divided into 3 pillars

  • Storage Virtualization – with Falconstor Network Storage Server (NSS)
  • Backup & Recovery – with Falconstor Continuous Data Protector (CDP)
  • Deduplication – with Falconstor Virtual Tape Library (VTL) and File-Interface Deduplication System (FDS)

NSS virtualizes heterogeneous storage platforms and sits in between the application servers, or virtualized servers. It simplifies disparate storage platforms by consolidating volumes and provides features such as thin provisioning and snapshots. In the new version, NSS now supports up to 1,000 snapshots per volume from the previous number of 255 snapshots. That is a 4x increase as the demand for data protection is greater than ever. This allows the protection granularity to be in the minutes, well meeting the RPO (Recovery Point Objectives) standard of the most demanding customers.

The NSS also replicates the snapshots to a secondary NSS platform at a DR to extend the company’s data resiliency and improves the business continuance factor for the organization.

In a revamp new algorithm in version 7.0, the Microscan technology used in the replication technology is now more potent and higher in performance. For the uninformed, Microscan, as quoted in the datasheet is:

MicroScan™, a patented FalconStor technology, minimizes the
amount of data transmitted by eliminating redundancies at the
application and file system layers. Rather than arbitrarily
transmitting entire blocks or pages (as is typical of other
replication solutions), MicroScan technology maps, identifies, and
transmits only unique disk drive sectors (512 bytes), reducing
network traffic by as much as 95%, in turn reducing remote
bandwidth requirements.

Another very strong feature of the NSS is the RecoverTrac, which is an automated DR technology. In business, business continuity and disaster recovery usually go hand-in-hand. Unfortunately, triggering either BC or DR or both is an expensive and resource-consuming exercise. But organizations have to prepare and therefore, a proper DR process must be tested and tested again.

I am a certified Business Continuity Planner, so I am fully aware of the beauty RecoverTrac brings to the organization. The ability to test non-intrusive, simulated DR, and find out the weak points of recovery is crucial and RecoverTrac brings that confidence of DR testing to the table. Furthermore, well-tested automated DR processes also eliminates human errors in DR recovery. And RecoverTrac also has the ability to track the logical relationships between different applications and computing resource, making this technology an invaluable tool in the DR coordinator’s arsenal.

The diagram below shows the NSS solution:


And NSS touts to be one true any storage platform to any storage platform over any protocol replication solution. Most vendors will have either FC or iSCSI or NAS protocols but I believe so far, only Falconstor offers all protocols in one solution.

Item #2 in the upgrade list is Falconstor’s CDP solution. Continuous Data Protection (CDP) is a very interesting area in data protection. CDP provides almost near-zero RTO/RPO solution on disk, and yet not many people are aware of the power of CDP.

About 5-6 years ago, CDP was hot and there were many start-ups in this area. Companies such Kashya (bought by EMC to become RecoverPoint), Mendocino, Revivio (gobbled up by Symantec) and StoneFly have either gone belly up or gobbled up by bigger boys in the industry. Only a few remained, and Falconstor CDP is one of the true survivors in this area.

CDP should be given more credit because there are always demand for very granular data protection. In fact, I sincerely believe that both CDP, snapshots and snapshot replication are the real flagships of data protection today and the future because data protection using the traditional backup method, in a periodic and less frequent manner, is no longer adequate. And the fact that backup is generating more and more data to keep is truly not helping.

Falconstor CDP has the HyperTrac™ Backup Accelerator (HyperTrac) works in conjunction with FalconStor Continuous Data Protector (CDP) and FalconStor Network Storage Server (NSS) to increase tape backup speed, eliminate backup windows, and offload processing from application servers. A quick glimpse of HyperTrac technology is shown below:


In the Deduplication pillar, there were upgrades to both Falconstor VTL and Falconstor FDS. As I said earlier, CDP, snapshots and replication of the snapshot are already becoming the data protection of this new generation of storage solutions. Coupled with deduplication, data protection is made more significant because it makes smart noodles to keep one copy of the same old files, over and over again.

Falconstor File-Interface Deduplication Systems (FDS) addresses the requirement to storage more effectively, efficiently, economically. Its Single Instance Repository (SIR) technology has now been enhanced as a global deduplication repository, giving it the ability to truly store a single copy of the object. Previously, FDS was not able to recognize duplicated objects in a different controller. FDS also has improved its algorithms, driving performance up to 30TB/hour and is able to deliver a higher deduplication ratio.


In addition to the NAS interface, the FDS solution now has a tighter integration with the Symantec Open Storage Technology (OST) protocol.

The Falconstor VTL is widely OEM by many partners and remains one of the most popular VTL solutions in the market. VTL is also enhanced significantly in this upgrade and not surprisingly, the VTL solution from Falconstor is strengthened by its near-seamless integration with the other solutions in their stable. The VTL solution now supports up to 1 petabyte usable capacity.


Falconstor has always been very focused in the backup and data recovery space and has done well favourably with Gartner. In January of 2011, Gartner has release their Magic Quadrant report for Enterprise Disk-based Backup and Recovery, and Falconstor was positioned as one of the Visionaries in this space. Below is the magic quadrant:


As their business model changes to a more direct approach, it won’t be long before you seen Falconstor move into the Leader quadrant. They will be soaring, like a Falcon.