ExaGrid's Eye on Deduplication

In part 1 of our “5 Ways Disk Backup Can Help Your Business” blog series, we discussed how a disk-based backup solution helps businesses get faster backups as their data grows and in part 2 of this series, we discussed how to avoid failed tape backups and restores by using a disk backup solution. In part 3, we discuss how a disk backup system with data deduplication provides better, faster offsite disaster recovery.

The need for fast and simple restores to recover data during a site disaster is a business imperative for many companies. With tape-based data protection, the longest delays in recovering from a system or site disaster are often due to the need to acquire, load, and restore data from offsite tapes. Recovering the right tape from offsite can take a day or up to several days. But tapes are often lost, misplaced, or are otherwise faulty – and the time it takes to complete a recovery operation increases considerably if one or more of the backup tapes is found to be corrupted or damaged. When this occurs, older backup tapes must be used, resulting in a longer overall recovery process – and the data finally restored to users and applications may be weeks old.

Fast and Simple Disaster Recovery Using Disk Backup System

With a disk backup system with data deduplication, an optional offsite disk-based backup appliance can replace offsite tape and provide faster, more reliable data recovery. The byte-level changes from backup to backup on a local site system are replicated efficiently to an off-site system. Since it is only these byte-level changes that are replicated, typically only about 2% of the backup traverses the WAN. In the event of a primary site disaster, it takes just a few seconds to initiate a data recovery process at the second site using the existing backup application. 

In addition to facilitating the replacement of offsite tape, certain disk backup with data deduplication systems (such as ExaGrid) also provide proprietary “instant DR” technology for even faster recovery from an outage or disaster.  With “instant DR,” when a new backup at the primary site is replicated to the remote site by sending over just the bytes that have changed, the remote site takes these changed bytes and combines them with previous backups to create a complete copy of the most recent backup on the remote site.  Keeping this most recent backup intact and ready to be restored makes disaster recoveries much faster, giving the customer “instant DR” should the need arise.

ExaGrid provides a disk backup with data deduplication system which enables fast offsite DR. An excellent example of an ExaGrid customer using these DR capabilities is The Coastal Bank. They credit receipt of the highest Possible FDIC regulatory rating of “1” in part to use of ExaGrid’s disk-based backup system. In The Coastal Bank case study, they describe how restores that previously took an hour or more, and much longer if restoring from an offsite storage location, are accomplished in as fast as 5 minutes.

ExaGrid also continues to stay on the cutting edge of offsite disk-based data protection through the support of technologies such as Symantec OpenStorage API. Using ExaGrid disk backup system with Symantec OpenStorage API provides a number of benefits, including unified control and access of backup data stored on both local and remote ExaGrid systems, varied amounts of retention for on-site vs. off-site systems, simplified disaster recovery, and shorter backup windows. For additional information on ExaGrid disk backup with data deduplication system and Symantec OpenStorage API, please visit:

ExaGrid and Symantec Backup Exec 2010 OST Data Sheet

ExaGrid and Symantec NetBackup OST Data Sheet

In part 1 of our “5 Ways Disk Backup Can Help Your Business” blog series, we discussed how a disk-based backup solution helps businesses get faster backups as their data grows. In part 2 of this series, we discuss how disk backup with data deduplication helps reduce or eliminate failed tape backups.

One of the most consistently annoying challenges in backup operations is the prevalence of tape backup failure. Estimates show that 15 to 30% of backups to tape based media fail while 30% or more of restores from tape fail.

The percentage is significantly higher if you broaden the definition of a backup failure.  While most people do not count a backup job that exceeds your backup window as a failure, there is a pretty good argument that it is indeed a failure. Many organizations that I speak to have strict policies that backups cannot run after a certain hour and therefore any that are still running are shut off.  Even if you can allow them to keep running into the business day, no one would advocate that you can sustain that mode of operation, so “failure” is the right label.

Eliminate Tape Failures Without Throwing Your Library Out The Window

Because tape itself is at the heart of a lot of the failures organizations experience, it is hard to see a better future without taking tape out of the equation. However, there are things that can be done to eliminate some of the failures associated with tape without throwing your library out the window:

• Clean the tape drives at least as often as the vendor recommends. Like oil changes, these guidelines represent a minimum amount of care required to keep things running.
• Though costly, perform all required maintenance on the drives and library. Tape systems are highly mechanical and require diligent attention to avoid catastrophic failure.
• Bite the bullet and pay for the vendor technician to come in a replace worn parts.
• When it’s done, it’s done. When the old gray mare just isn’t what she used to be, it’s time to replace the library. 

If all of the above sounds a lot like a trip to the dentist where you hear “Oops, out of novocain”, then perhaps its time to consider disk backup as an alternative to tape. With the advent of lower cost disk technologies combined with data deduplication, you may find that some vendors (though not all) offer disk-based backup appliances that are cost competitive with a tape library replacement. At ExaGrid, we have made it our mission to rival tape library costs with our disk backup appliances.

Enter disk, exit the issues of tape and the associated backup failures. This includes the “failures” where the backup’s jobs are simply not finishing during the window.  Because disk backup is faster than tape and supports greater concurrency, you will not only eliminate media errors, jammed tape drives, and so on, you will see faster backups.

Learn how Gardner Trucking recovered quickly from a system crash after replacing tape and avoided a loss of $200,000 in business and productivity by having made the switch from tape to a disk backup with data deduplication system. Is it time for you to make the switch from tape to disk backup? 
 
 

This post is the first in a series to share with you 5 ways disk backup can help your business:

1. Faster Backup Times
2. Reduce or Eliminate Failed Backups
3. Better, Faster Offsite Disaster Recovery
4. Time and Cost Savings
5. Improved Recovery Time (RTO/RPO)

In this post, we will discuss the first topic--how disk backup enables IT organizations to dramatically reduce their backup times.

1.      Faster Backup Times

While tape backup systems have been in use for many years, the slow speed of tape backup devices is a major reason many organizations have looked for a better, faster way to back up their data.  One of the key reasons many organizations move to a disk backup solution is in fact the inherent advantage of disk for faster backups.  Moving from tape to disk will get you faster backups, but it is also important to choose the correct disk backup approach, and to ensure that you will continue to get faster backup times as your data grows.

Disk vs. Tape

While some might argue that some tape-based approaches might allow for a particular backup job to move at rate on par with disk, the key advantage of disk-based backup over tape is the ability to run a large number of backup jobs in parallel.  The number of backup jobs you can run via tape-based backup is only as high as the number of tape drives in your tape library – at most four simultaneous backup jobs can target a four-drive tape library, for example.  This limit is much higher with disk – a 50TB ExaGrid system can support up to 100 simultaneous backup jobs – and the ability to run this many backup jobs in parallel will allow for much higher backup speeds with disk over tape. Click here for additional discussion of disk backup vs. tape backup performance.

Post-process vs. Inline Deduplication

Once you have decided to move to a disk-based backup system, to achieve fastest backup times, it is important to consider the various deduplication approaches available when deciding which system to choose. This decision typically comes down to a choice between inline deduplication and post-process deduplication.

With inline deduplication, backup data is sent to the disk backup system and is processed and deduplicated as the data comes into the system.  Since all of the data coming into the system is being deduplicated on the fly, this can slow the backup down significantly, potentially creating a bottleneck at the point of entry into the backup system.

Post-process deduplication allows backup data to be written to disk without any processing interfering with the backup flow.  A post-process system compresses and deduplicates the data after the backup job has landed on the disk – not as the data is coming into the system.  This is the approach that the ExaGrid system uses. Since nothing is done to the data as it comes into the ExaGrid system, the data can be written at the highest possible rate, giving you the smallest possible backup window.

Planning for Growth

While it is desirable to strive for as short a backup window as possible today, it is also important to keep that backup window short over time, as your data grows.  After all, what good is a short backup window if it’s just going to get longer as your backup jobs get bigger?

With some of the current appliance architectures, keeping the backup window short while allowing for data growth means replacing your backup appliance with bigger and more powerful models of that appliance.  This occurs because many of these disk backup systems use what is called a controller-disk shelf model, where all of the processing power, memory, and bandwidth are on a single controller system, and expansion occurs by simply adding shelves of disk (with no incremental addition of controller components) to the system.  This is not the best solution, as eventually your data needs eventually outstrip the original controller component, and you end up migrating to a system with a more powerful controller and start the process all over again. The result is greater expense and greater management costs as you migrate your data to ever-larger appliances as your data needs grow. 

A better alternative is a grid-based system.  With a grid-based system, each appliance in the system brings with it not only additional disk, but also additional memory, bandwidth, and processing power – all the elements needed to maintain high backup performance.  With ExaGrid’s grid-based disk backup system, keeping your backup window short as your data grows is simply a matter of adding additional appliances to the grid.  There is no need to replace less powerful appliances with more powerful ones – you simply add more appliances to the grid as suits your needs. You get the shortest possible backup times, with the ability to easily keep those times short as your data grows, over time.

Want to learn more about making the move from tape to disk backup with deduplication? Download '7 Steps for Overcoming Limitations of Tape Backup' here.

Hospital Backups Reduced 75% from 24 to 6 Hours with Data Deduplication Solution

One of the main problems we hear over and over again from customers is the need for them to reduce their backup times.  IT staff backing up with tape will take any of a variety of steps to try and reduce backup times, such as cutting-back the amount of data backed-up nightly, changing rotations, and adding more drives to the tape library, if that is possible.  Eventually there are no more work-arounds. The story of how MemorialCare tackled this problem with disk-based data deduplication--and also provided for better offsite disaster recovery--is one I thought you would find interesting.

MemorialCare is a leading nationally recognized, not-for-profit health system with six hospitals in California. MemorialCare’s IT Operations department was responsible for managing and protecting over 150 servers containing patient and business data. Continuous and around the clock data backups were extremely labor intensive and stressing out the IT staff. Backups ran 12 to 18 hours a day and with data vaulting, the total backup window was nearly 24 hours, consuming 200-300 backup tapes per week. Difficulty restoring data from tape was also causing problems.

MemorialCare’s IT staff decided to look at new ways to protect its data, considering both straight disk and disk-based backup with data deduplication options. “Straight disk without data deduplication simply wasn’t cost-effective. We looked at several different disk-based backup solutions and chose ExaGrid based on its price, performance, manageability, support and reliability,” said Jorge Cepeda, Network Engineer at MemorialCare. “The ExaGrid system enabled us to significantly reduce our backup window and really makes the whole backup process painless. Also, the fact that we could replicate data between two ExaGrid systems was important because we could act as our own disaster recovery center.” MemorialCare installed two ExaGrid disk-based backup with data deduplication systems at two hospital locations, working alongside their backup application, Symantec/Veritas NetBackup. Eventually, MemorialCare plans to place ExaGrid’s data deduplication systems at each of its six hospitals and replicate the data between locations for disaster recovery.

ExaGrid’s byte-level data deduplication technology stores changes from backup to backup instead of storing full file copies. This unique approach reduces the disk space required by a range of 10:1 to 50:1 or more, delivering unparalleled cost savings and performance. MemorialCare now completes its nightly backups in six hours, and no longer needs to vault its data because the backup is replicated onto its second ExaGrid system.

MemorialCare Meets Green Initiative, Streamlines Backup Process with ExaGrid’s Disk-Based Data Deduplication

Many of our customers have Green IT initiatives, and MemorialCare also had one, where they were focusing on reducing data center power requirements and rack space. At just 3U, ExaGrid’s compact size helps maximize rack space and its 120 volt power supply draws less power than other disk-backup solutions that require 220 volts. Additionally, ExaGrid’s GRID computing software makes the system highly scalable, and when plugged into a switch, different sized configurations can be mixed and matched into a single GRID system with capacities of up to 60TB.

“The ExaGrid fits in nicely with our green initiative. Because the ExaGrid is an appliance, we can scale incrementally. Other vendors required us to purchase racks of equipment with greater power and cooling requirements,” said Jorge Cepeda. “We’ve been working closely with ExaGrid’s support team to streamline our backup processes even further. We have a technician assigned to our account that is always accessible, familiar with our environment and is extremely knowledgeable about backups. It’s nice to be able to leverage that expertise.”
  
Yet another customer whose backups were made better by switching from tape to disk-backup with data deduplication.

Disk-Based Data Deduplication Reduces Bank’s Backup Window

American National Bank and Trust Company is a Mid-Atlantic regional bank with a rich history reaching back to 1909. When nightly tape backups reached 12-hours along with requiring runners back and forth between locations to restore corrupt tapes, American National Bank and Trust began looking for a more secure and reliable data backup system.  

American National Bank and Trust was going through as many as 35 tapes every two weeks, which were stored offsite. While eliminating tape and reducing the 12-hour backup window were primary deciding factors, they were looking for solutions that would address increased auditing requirements, compliance and improve security with faster and more reliable restores and backups.

American National Bank and Trust's Network Administrator and IT staff looked at several solutions including virtual tape library (VLT), disk repository systems without data compression, straight SATA and disk-based data deduplication. Their Network Administrator stated, “Cost was an important factor for us. We looked at VTL systems and found them cost-prohibitive. Also, we considered adding straight disk to our SAN, but it would have been expensive and more complex because we would have had to configure and manage it on our own.” Disk repository systems were also evaluated but proved expensive. They did not offer compression, and would have needed a larger capacity and more expensive appliance.

ExaGrid Data Deduplication Proved Best for Reducing Backup Window and Disk Space

American National Bank and Trust chose ExaGrid’s disk-based data deduplication for their cost benefits, combined with the ability to put so much data on a smaller system. This made the ExaGrid data deduplication system much more feasible than the other solutions. They have seen their backup window drop from 12 hours to 6 and has seen the amount of backup data stored reduced significantly, even though data retention periods have remained consistent.

ExaGrid’s data deduplication solution combines standard data compression for the most recent backups, along with byte-level delta data reduction for all previous backups. This byte-level delta data reduction technology stores changes from backup to backup instead of storing full file copies. This means ExaGrid appliances implement target-based data deduplication and carry out deduplication post-process. This allows long-term backup history to be cost-effectively stored on disk.

Intelligent, Cost-Effective Data Protection                                                    

ExaGrid provided a cost-effective and scalable data backup system solution for American National Bank and Trust that combined high quality SATA drives, compression, and data reduction through data deduplication for fast and reliable backups and restores that seamlessly integrated with their existing backup system, Symantec Backup Exec. “Setting up the ExaGrid was really simple. There were only a few steps – even a beginner could set it up,” said American National Bank and Trust's Network Administrator. “All we had to do was set up a file share on the ExaGrid, and then point Backup Exec to it. ExaGrid takes care of everything else. We never have to touch it.”

After 3 years deployment, American National Bank and Trust continues to benefit from using ExaGrid’s disk-based data deduplication system.

As the amount of data that businesses depend on grows, the need for faster and more reliable data backup becomes even more crucial. When your backup system begins to drain time and resources, it can affect a firm’s ability to deliver time-sensitive information that drives revenue. Bird & Bird, an international law firm, recognized that their tape backup system was slowly eating away at their ability to protect their data and respond to clients efficiently. Bird & Bird focuses on telecoms, multimedia, information technology and intellectual property legal issues through 21 offices worldwide. Their clients include some of the most innovative, technology advanced global companies, and in the legal industry… time is crucial. Accessing legal documents quickly is paramount in delivering legal advice that meets their client’s business objectives.

The Data Backup Problem

Bird & Bird consolidated much of their data management to a central London location four years ago. As their business and client roster grew, so did their quantity of data. Finding a solution to manage data backup effectively became a priority. Jon Spencer, Infrastructure Manager at Bird & Bird stated, “A full backup that started on Friday was filling about 20 LTO-3 tapes with 12 TB at 1.5:1 compression and often ran into Monday or Tuesday.” As tape backup was conducted at a separate facility for security issues, it could take hours for users who often needed to recall documents from the backup tapes. Another concern was the time and resources consumed by tape backup. Because of the amount of time Bird & Bird’s weekly tape backup was taking, if the tape was still in use, they could not restore files from their media.

Evaluate Multiple Disk Backup Vendors

Spencer concluded that adding more tape backup would not solve his problems and decided to explore disk-backup systems. After researching multiple vendors, Bird & Bird decided to evaluate five industry leaders and the firm borrowed disk backup appliances from Data Domain, ExaGrid Systems, FalconStor Software, Quantum as well as Symantec’s NetBackup PureDisk software product to begin an evaluation process.

Bird & Bird set-up these five products  interfaced with their media server and then ran a series of data backups and restores using the same Exchange backups and flat-file data each time. Spencer said, “Evaluations are important to me as you get an indication as to the efficiency of the organization and you get to meet the techie guys too.” Knowing the level and commitment of customer service during and after the sale can be a decisive factor. Although Spencer concluded from the testing that there was little difference between the five manufacturers in terms of backup/restore speed, several products were eliminated because of scalability issues or because the product would have required changing the backup application. Spencer also decided not to go with a source data deduplication product because of concerns about the effect on host systems of a source-based dedupe product.

Bird & Bird narrowed down the original five vendors to two, ExaGrid Systems and Data Domain. In the end, Bird & Bird went with ExaGrid Systems based on its ability to centrally manage geographically dispersed units and its user interface. Spencer also liked ExaGrid’s smaller organization as he concluded ExaGrid was more adaptable to Bird & Bird’s specific needs and provides proactive customer service support.

In Data Backup, Look at What Approach Best Solves Your Needs

Bird & Bird achieved their backup objectives with ExaGrid systems offering 20TB of capacity in London and 1TB in Hong Kong.  The law firm runs daily incremental and weekly full backups through the ExaGrid devices and archives to a tape library once a month.

Unlike other devices, the ExaGrid devices implement target-based data deduplication and carry out data deduplication post-process. This process means data deduplication is done after data has been sent to the device and is held in a landing area. According to Spencer, the post-process data deduplication holds no disadvantage. "I don't take too much notice of what the ExaGrids are doing once the backup is finished. As soon as the job has completed, it is available for restore if required and that is all we care about.”  Bird & Bird has achieved a data deduplication ratio of 14:1.

Bird & Bird has almost immediate availability of restores, which now take minutes rather than hours. They keep between three weeks and eight weeks of backups on the ExaGrid machines. The backup window has been reduced by a third and is carried out with seven or eight backup streams instead of the two or three it could manage with tape.

Are your backups draining time and resources?

Just like Bird & Bird did, seek out alternative disk backup solutions, evaluate the capabilities and find a system that delivers the best value for your business.

An increasing number of organizations are making the move from tape to disk backup with deduplication, so we're pleased to share lessons learned from our customer base of 2,400+ installations with you. Below are 7 tips and best practices that will help you assess the potential fit and steps you might take for moving from tape to disk backup.

Tip 1: Realistically assess the shortcomings of tape and potential consequences 

Everyone knows that tape can be cumbersome and require a considerable amount of manual intervention to successfully perform regular backups. Tape backups must be monitored, equipment needs to be maintained and heads must be cleaned for backups to run properly. Tapes must be loaded and changed, labeled correctly, and physically transported off-site for disaster recovery. In virtualized server environments, many backup applications do not support tape, and tape does not allow use of advanced options in backup software.

As an organization's data grows, many organizations face long nightly backup windows, and in many cases, backups can't always be completed within the allotted timeframe. That means backups are often aborted, leaving incomplete data that may be unusable in the event of an emergency. And even if a tape backup is performed successfully, the data isn't always available for a number of reasons.

Here are some sobering tape backup statistics to consider:

Business Impact of Failed Tape Backups

The downsides of using tape can affect virtually every person who works within an organization or who does business with it. Users and customers are negatively impacted, not to mention the IT department. Below are a few examples:

According to the National Computer Security Association, without adequate backup, it takes 21 days and $19,000 to recreate 20MB of lost accounting data, and 42 days and $98,000 to recreate 20MB of lost engineering data.

When a major U.S. trucking company suffered a recent crash, they achieved significant savings with a quick recovery that resulted from using disk with deduplication instead of tape. They avoided two days of system downtime and a loss of $200,000 in business and productivity that would have resulted if they had to restore their database from their previous tape backup system.

In one highly-publicized incident, a 2007 data backup failure by the Alaska Department of Revenue wiped out data on a $38 billion account and cost the state $200,000 to restore the data.

 

Tip 2: Determine your key drivers and align them with budgetary priorities

Projects to replace tape are invariably tied to a failure of existing systems to execute reliable backups, a need for better IT productivity or cost savings, or a new business initiative. Below are six of the most common drivers for replacing tape with disk.

1. Backup times exceed the available backup window (and everything practical to bring backup times back in the window has been tried)
   
2. Tape library is dying or dead, or the IT maintenance burden or costs have become excessive
3. Project to improve offsite disaster recovery, and need something better than tape for RPO and RTO
4. Currently writing to straight disk, and the amount of disk is growing and getting expensive
5. VMware/virtualization backup project, and you want to go all disk and shut off tape
6. Data center consolidation project

Tip 3: Take a side-by-side comparison of tape headaches and disk benefits

Fortunately, it's now possible to significantly streamline the backup process with disk. Disk provides numerous benefits over tape, so that backups are painless and successfully completed each night.

Tip 4: Understand how data deduplication and compression technologies are putting disk-based backup within reach.

Disk-based backup systems combine low-cost SATA disk, data compression, and data deduplication to provide fast and reliable disk-based backups and restores at about the price of tape. Utilizing data deduplication and compression, backup data can be stored in anywhere between 1/10th to 1/50th the storage space, greatly reducing the disk needed for backup and therefore cutting the overall cost. Using these systems, organizations can reduce or eliminate tape and shorten backup windows by as much as 30 to 80 percent with the small footprint of disk.

Consider the case of an organization that keeps 12 full backups on-site or off-site. Without data deduplication, 60TB of disk would be required to backup 5TB of data, at a total cost which would make disk backup impractical. Using disk backup with deduplication to backup the same 60TB of data is far less expensive. Only the bytes that have changed are stored for each previous backup, and since just two percent of bytes typically change from backup to backup, the result is that only the 100GB that change at the byte-level per week (out of the original 5TB) need be stored. Taking it one step further, the most recent backup (compressed to 2.5TB) plus 11 weeks of byte-level deltas at 100GB gives you a total of 3.6TB (2.5TB + 11 x 100GB). Instead of taking 60TB, the use of compression and deduplication brings the total down to 3.6TB.

Tip 5: Define functional requirements to meet business goals

Once it has been determined that tape is going to be replaced by disk backup with data deduplication, the following essential capabilities should be considered:

1. Storage efficiency ranging from 10:1 to 50:1 via byte-level data deduplicatio
2. Quick installation with a turnkey plug-and-play appliance
   
3. No change to your existing backup application via NAS interface
4. Shortest backup window, using post-process deduplication
5. Fastest restore and tape copy by storing a full recent backup copy
6. No performance degradation or forklift upgrades as data grows via GRID scalability
7. Scalability from 1TB to 100TBs (over 1 Petabyte logical)
   
8. Fast disaster recovery via WAN-efficient replication and rapid restore of last full copy
9. Deduplication and replication status via job-level reporting
10. Low price and IT operational costs through architecture purpose-built for backup

Tip 6: Eliminate tape and cost-effectively replace it with disk

Organizations use disk backup with deduplication to cost-effectively eliminate tape on-site, and optionally to also eliminate tape entirely for both on-site backup and long-term off-site retention. Disk backup with deduplication is extremely economical for a second site because the data deduplication technology only moves changes, so minimal WAN bandwidth is required. In a typical scenario where only two percent of the data has changed, disk backup with deduplication delivers as much as a 50:1 data efficiency over the WAN. Once the first backup is sent to the remote site, only the bytes that change are sent. And the software on most systems is intelligent enough to merge those bytes that change into the off-site backup, so that both backup copies are entirely up to date with the most recent backup. The systems can also cross-protect, so two sites can act as disaster recovery sites for each other. A combined on-site and off-site system would completely eliminate tape, provide significantly faster backups and restores, and reduce IT intervention, management and maintenance. It also ensures superior security, since the system and its data sits in a data center environment.

Despite the clear operational advantages of shorter backup and recovery times, greater reliability, reduced risk of failure, increased data retention, and enhanced IT productivity, improving backup via disk-based backup with deduplication requires an investment whose payback can be difficult to quantify. Fortunately for IT managers, significant performance and productivity gains are achievable at a cost comparable to tape, and some customers report paybacks in as fast as several days to 6 months. Check out the complete guide for more information on this.

Tip 7: Entrust your backup to vendors and value-added resellers with a track record of success

Customers looking to replace tape with disk will typically turn to vendors or value-added resellers with whom they already have a trusted relationship. Be aware that many larger IT vendors do not offer a best-of-breed disk backup with deduplication solution that satisfies the requirements of Step 5.

As you look to partners and vendors, make sure you can verify the track record of successful deployments for the specific disk backup product you are considering. While some tape-drive providers are introducing new disk-based solutions, they may not have a track record of successful deployments with the new technology, leaving your investment and data protection at risk. As older tape backup technologies need to be replaced, organizations should look for customer success stories with other similar users, and also perform a cost/benefit analysis to evaluate which backup technology best meets their budget and functional needs.

To get more details, click here to get the complete 7-Step tape replacement guide.

One of the blogs I most frequently read is the Mr. Backup Blog, written by Curtis Preston.   He continues his valuable role as a customer watchdog for our industry.   Most recently, he observes that vendors who supply disk-based backup with deduplication appliances which employ post-processing deduplication publish only their ingest rates and not the rates at which they post-process (i.e. deduplicate and replicate data).

Curtis raises a good point about publishing these numbers.  At ExaGrid, as we dialogue with our prospective partners and customers, we have always talked about the following:

• Product ingest rate - this is the speed at which data lands to disk during backup and defines the customer's backup window. ExaGrid's current maximum rate here for a customer with 100 TB of primary data is 18 TB/hour with Symantec OST (both Backup Exec and NetBackup), and 12.6 TB/hour without OST. As a result, we provide the shortest backup window in the market.
• Post-processing rate - this is the speed at which we deduplicate and replicate the data.  Here, we achieve a rate of 7.2 TB/hour for the configuration described above.  This rate is among the fastest for deduplication engines in our market including both post-processing and in-line implementations.

However, we typically have not displayed this prominently on our web site. Our upcoming web site updates will change this.

As always, the goals of ExaGrid's advanced post-processing deduplication approach are to:

• Deliver the customer the shortest possible backup window by landing backups as quickly as possible with no in-flight processing to slow backups.
• Retain a full copy of the most recent backup set to provide the fastest restores without incurring the overhead or reading deduplicated data. Customers will often say that 95% of restores are from that most recent backup, so this approach avoids deduplication overhead for 95% of all restores.
• Get the data offsite as rapidly as possible to protect against disaster.
• Offer the customer the ability to tune the product so that they can balance the size of the local backup window with the time it takes to replicate the data off site by allowing them to select the timing of deduplication/replication.

Obviously, there will be those that try to create myths about post-processing deduplication.  Here are my favorites:

• Myth 1 - Post-processing systems require more complex management
• Truth: ExaGrid's software does it all. You point your backups at a NAS share, we do the rest automatically in our software.
• Myth 2 - Backups cannot run while post-process deduplication is running
• Truth #1: ExaGrid's deduplication engine automatically allows for backups to flow simultaneously if and when necessary. In fact, if a customer environment cannot take full advantage or our ingest rate, we will automatically kick off deduplication and replication during the backups.
• Truth #2: When sensible, a customer can actually configure the ExaGrid product to land backups and deduplicate simultaneously.
• Myth 3 - Restores cannot be performed while deduplication is running
• Truth: Restores can be run at any time after a backup job is complete, whether deduplication is running or not.
• Myth 4 - With limited hours during the day, post-processing has to run a race to keep up.
• Truth #1: This is simple. As ExaGrid sizes a system for prospective customers, we take into account how much data they backup per day, per week, etc. In fact, about 95% of our customers do a full backup on the weekend and backup a sub-set of their data on week days (incremental on files, fulls on databases and e-mails). So the largest backup is done on the weekend when our rapid post-processing is complete long before Monday's backups.
• Truth #2: As stated before, deduplication can run during backups if and when necessary, so there is no backup failure if the processes overlap.
• Truth #3: All systems, regardless of how and when deduplication is done, have to be sized appropriately to handle daily backup amounts.

ExaGrid typically relies on our installed customers to validate our story.  With over 2400 systems installed at over 600 unique organizations, we have a large population of customers who will attest to the benefits our approach brings.  You can see 160 of them and read their stories at:

http://www.exagrid.com/why_exagrid/customer_success_stories.asp

The short answer to the question is yes. However, to really understand why, read on. In fact, there are multiple reasons that disk is faster than tape for backups and one of the reasons is the BIG reason.

Sometimes I will be approached by someone who will cite the LTO4 speeds with compression over a fibre network as they try to convince me that disk is actually slower or at best equal to tape. They cite the fact that most disk-based backup appliances connect over Ethernet and utilize a NAS interface. Therefore, there are bottlenecks that do not exist with tape.

Let's make this easy. Let's not even debate whether a single backup job to tape is slower than a single backup job to disk. For this moment in this blog post, let's call it a tie. Or better yet, for arguments sake let's allow just for this moment that tape could be faster (gasp!). Even in the rare case when this could true, this is not at all the horse race you care about. The key thing in backup is to complete all of your backups in the shortest time possible, specifically within your allowed backup window.

Disk gains a lot of its speed advantage through concurrency-the ability to run a lot of backup jobs in parallel. With tape, the number of backup jobs you can run simultaneously is limited by the number of tape drives in your tape library. With a 4 drive tape library, you can run 4 backup jobs simultaneously. The fifth, sixth, seventh, and eighth jobs patiently wait for a drive to be free. With disk, you do not have this limitation. For example, each ExaGrid appliance can handle between 6 and 20 concurrent backup jobs. A 60 TB ExaGrid System can support 120 concurrent backup jobs or streams whereas other systems may support as little as 18 for that amount of data.

A good comparison for this is draining a swimming pool. Imagine a swimming pool with 100 gallons of water in it. Let's assume I install two drains in the pool, each capable of draining 1 gallon per hour. Obviously, it will take 50 hours to drain the pool (100 gallons divided by 2 gallons/hour = 50 hours).

Now imagine the same pool but instead of two drains, I install 10 drains each capable of draining ½ gallon per hour. Even though each individual drain can only drain at half the rate of the drains in the other example, the pool will drain faster. The 10 drains will drain the pool at a rate of 5 gallons per hour versus 2 gallons per hour or more than twice as fast. The pool will drain in 20 hours versus 50 hours.
So, before you upgrade your tape library to the blazing fast speeds seen with LTO4, remember you will always be limited by the number of tape drives.

Folks, its time for disk-based backup. And with data deduplication in a plug-and-play appliance, it fits within even some of the tightest IT budgets.

Last week we were at Symantec's Vision Conference in Las Vegas along with thousands of Symantec's customers and dozens of other partners.  There were a number of interesting presentations on the topic of backup and deduplication.  We'd like to just share a few highlights for you. 

First, here are two short video interviews. Our VP of Product Management, Marc Crespi, was interviewed and talks about our joint disk backup product solutions with Symantec's Backup Exec and NetBackup Open Storage including customer successes.  In addition, I was interviewed and talked about benefits of our partnership with Symantec to partners and to customers, and how the product just works to replace tape in the nightly backup process. 

In the session, "Deduplication Everywhere," Symantec discussed the role of disk backup appliances in their ecosystem.  Here are a couple of points from their presentation on the Benefits of Appliance-Based Deduplication:

• OST advanced management and backup application integrated management provided by the appliance vendor
• Allows NetBackup and Backup Exec to track data and move data between appliances
• OST increased data movement performance efficiency
• Minimal changes to backup environment
• Faster restores from appliances than using that device natively (not a CIFS restore)

In addition to the above, you have fast offsite disaster recovery from disk via WAN-efficient replication, retention of weeks up to years, and GRID scalability to support high rates of data growth where performance and scalability are required.  Symantec's "Deduplication Everywhere" strategy and framework has a place for deduplication to meet the needs of all customers, and the role is a disk-based appliance is an important one.