Categories
Backup D2D Restore

Boost vendor lock-in

A couple of weeks ago, I blogged about the benefits of Symantec’s Open Storage Technology (OST). The technology enables accelerated disk-to-disk backups (D2D) primarily over IP connections and additional value-added features. Last week, EMC responded with their announcement of BOOST for NetWorker. Insiders have told me that the BOOST architecture is essentially the same as OST although the go-to-market strategy is very different. Of course a major difference is that OST has been shipping for over 3 years and BOOST will not be available until sometime in the second half of 2010.

As discussed previously, EMC/Data Domain was unable to create a true global deduplication solution so were forced to use OST to do the heavy lifting. Ironically, they could only support Symantec NetBackup and BackupExec with the new feature because NetWorker did not offer an advanced D2D interface. The BOOST announcement addressed the issues, but raises new questions. Specifically, BOOST is positioned as an EMC only solution, and it is unclear if the API will be shared with other vendors. In my opinion, this creates a challenge for EMC/Data Domain and NetWorker. Let’s look at how the situation impacts a variety of interested parties.

Categories
Backup D2D Deduplication Restore Virtual Tape

Streaming LTO-5

Chris Mellor (twitter:@Chris_Mellor) recently posted an article over at The Register about LTO-5 entitled Is LTO-5 the last harrah for tape?.  He makes an interesting point about the future of LTO and whether LTO-5 will be the last generation of the technology.  Most of the comments on the article disagree with Chris’s opinion.

I believe that there is another major issue with LTO-5 that must be addressed.  The challenge with LTO (and most other tape technologies) is its limited ability to throttle performance.  Users must carefully manage their environment to ensure that they stream their drives or else backup performance will decline dramatically.  As drives become faster, the challenge of optimizing your environment for the technology becomes more difficult.  You can read more about this in my blog post entitled The Fallacy of Faster Tape.

Categories
Backup D2D Restore

The Fallacy of Faster Tape

I often talk about disk-based backup and virtual tape libraries (VTL) and wanted to discuss physical tape. While VTLs are popular these days, tape is still in widespread use. LTO tape, the market share leader, continues to highlight increased density and performance. Do not be fooled with these claims. In the real world faster tape often provides little or no improvement in backup and/or restore performance. Ironically, faster tape increases (not decreases) the need for high performance disk devices like VTLs. Let me explain.

Modern tape drives use a linear technology where the tape head is stationary and the tape moves at high speed above it. Through each generation of LTO, the tape speed is largely unchanged while tape density doubles. At the same time, LTO drives have not expanded their ability to vary the speed of tape. Thus if you go from LTO-3 to LTO-4, you have doubled the density of your tape and you must double the throughput of data handled by the drive to keep tape speed unchanged. Why does tape speed matter? Because LTO tapes have a limited ability to throttle tape speeds, your performance will suffer terribly if you cannot meet the drives minimum streaming requirement.

If you are unable to stream enough data to your tape drives as mentioned above, the tape drive will go into a condition called “shoe shining” where it is constantly stopping and starting. It will try to stop when its buffer empties, but the tape is moving so fast that it will overshoot its stopping point and need to slowly stop, rewind to where it stopped writing and begin writing again. The tape moves forward and backward like shoe shine cloth. This process causes a massive reduction in performance and excessive wear on the tape drives and media. The table below comes from a Quantum whitepaper entitled “When to Choose LTO-3” and highlights the real world performance requirements of LTO-2 and LTO-3. I have estimated LTO-4 requirements for completeness.

Categories
Backup D2D Restore Virtual Tape

InformationWeek on NEC HYDRAstor

Howard Marks recently posted an interesting article about NEC’s HYDRAstor over on his blog at InformationWeek. He discusses the product and how the device is targeted at backup and archiving applications. He makes some interesting points and mentions SEPATON. I wanted to respond to some of the points he raised.

…[the system starts with] a 1-accelerator node – 2-storage node system at $180,000…

Categories
D2D Deduplication Virtual Tape

Analyst Commentary on VTL

I am often perusing industry related sites to find what people are saying about disaster recovery and data protection. Most of these sites rely on independent contributors to provide the content. Given the myriad of viewpoints and experience levels, it is not uncommon to see a wide range of commentaries, some consistent with industry trends, and others not. I keep this in mind when reading these articles and generally ignore inconsistencies; however once in a while an article is so egregiously wrong that I feel a response is necessary.

In this case, I am referring to an article appearing in eWeek where the author makes gross generalizations about VTL that are misleading at best. Let’s walk through his key points:

VTLs are complex

I completely disagree. The reason most people purchase VTLs is that they simplify data protection and can be implemented with almost no change in tape policies or procedures. This means that companies do not have relearn new procedures after implementing a VTL and thus the implementation is relatively simple and not complex like he suggests.

He also mentions that most VTLs use separate VTL software and storage. This is true for solutions from some of the big storage vendors, but is not the case with the SEPATON S2100-ES2. We manage the entire appliance including storage provisioning and performance management.

Finally, he complains about the complexity of configuring Fibre Channel (FC). While it is true that FC can be more complex than Ethernet it really depends on how you configure the system. One option is to direct connect the VTL which requires none of the FC complexities he harps on. He also glosses over the fact that FC is much faster than the alternatives which is an important benefit. (My guess is that he is comparing the VTL to Ethernet, but he never clearly states this.)

Categories
D2D Deduplication Virtual Tape

Tape is not dead!

I am amazed when I hear some vendors aggressively promote that tape is dead. It seems that hyping the demise of tape is in vogue these days and the reality is quite different. Even so,  there is no stopping them from sharing their message with anyone who will listen. If you ask large enterprises, many of them are looking at alternatives to tape, but telling them that tape is completely dead and that they should rip out all tape hardware is ludicrous. Ironically, this is the approach of some deduplication vendors.  Jon Toigo states this succinctly in his blog.

The problem with tape is that it has become the whipping boy in many IT shops.
Courtesy: Drunken Data

The simple reality is that tape has been an important component of data protection for years and is likely to maintain a role far into the future. The reader should remember that in today’s highly regulated environments, companies often face strict requirements about data retention. For example, medical institutions can face some of the most stringent requirements:

HIPAA’s Privacy Rule, in effect since 2003 or 2004 depending on the size of the organization, requires confidentiality of patient records on paper and sets retention periods for some kinds of medical information, regardless of media. These retention requirements can stretch from birth to 21 years of age for pediatric records, or beyond the lifetime of the patient for other medical records.
Courtesy: Directory M

With this in mind, let’s look at the evolution of tape: