Month: November 2008

Categories
General

10 Things I Am Thankful For

The Thanksgiving holiday is a time to reflect on things that you are thankful for and so I figured that this would be a great topic for my one blog post this week.

1. That the Somali pirates have not hijacked SEPATON although Bloomberg suggests in a humorous press release that Citibank may be in their sights.
2. That the backup guy is no longer treated like an ugly step child and locked in the tape silo when naughty.
3. That data retention requirements are likely to get even stricter thanks to our friends on Wall Street.
4. I have a job.
5. My job is not selling Rube Goldberg contraptions.
6. Data Domain has spent millions educating the market on why dedupe matters but only offers solutions for SMBs.
7. That all those cubicle gophers are still jacking up their company’s capacity requirements by downloading, sharing and storing all of their personal MP3s, videos and photos.
8. That gas prices have declined so I no longer have to skateboard to work.
9. Our VTL is so easy to install and operate that a consultant with no SEPATON experience set it up and got it running in 15 minutes.
10. That the loud CS guy who sat across from me was relocated to the broom closet. 🙂

Feel free to post what you are thankful for in the comments. Have a great Thanksgiving.

Categories
Deduplication Virtual Tape

Choosing a Data Protection Solution in a Down Economy

I hate to turn on the TV these days because it is full of bad news. There always seems to be some pundit talking about troubles in the housing market, credit markets, automotive industry, consumer confidence and so many other areas. It does not take a rocket scientist to recognize that the economy is in tough shape right now. As a reader of this blog, you are likely feeling some of the pain in your budget. This obviously brings up an important question: how do I justify IT purchases in these environments.

In situations like these, IT departments must go back to the basics. Purchases must be all about ROI. You must look beyond just acquisition cost and consider how a given solution can save your organization money both upon acquisition and into the future.

Continue reading “Choosing a Data Protection Solution in a Down Economy”
Categories
Backup Restore

SEPATON S2100-ES2 Performance

The SEPATON S2100-ES2 was designed for speed. Our solution is based around the concept of a unified appliance which provides one GUI for managing and monitoring all embedded hardware. We also automate the disk provisioning and configuration to provide consistent scalability and performance. The result is an appliance that can easily be managed by an administrator who understands tape and wants to avoid the traditional complexities of disk.

Our performance is quite simple to understand. We use a grid architecture which means that all nodes can see all storage and can access the same deduplication repository; you can backup and restore from any node. Today we support five nodes with DeltaStor while the VTL supports 16. We will be adding support for larger node counts in the near future. Each node provides an additional 2.2 TB/hr ingest and 25 TB/day deduplication performance. The appliance deduplicates data concurrently that means that backups and dedupe occur simultaneously with no performance impact. Let’s look at the actual numbers.

Continue reading “SEPATON S2100-ES2 Performance”
Categories
Deduplication Restore

Deduplication, Restore Performance and the A-Team

I have posted in the past about the challenges of restoring data from a reverse referenced deduplication solution. In short, the impact can be substantial. You might wonder whether I am the only one pointing out this issue, and what the impact really is.

An EMC blogger recently posted on this topic and provided insights on the reduction in restore performance he sees from both the DL3D and Data Domain.  He said, “I will have to rely on what customers tell me: data reads from a DD [Data Domain] system are typically 25-33% of the speed of data writes.” He then goes on to confirm that “…the DL3D performs very similarly to a Data Domain box”. He is referring to restore performance on deduplicated data in reverse referenced environment. (Both Data Domain and EMC/Quantum rely on reverse referencing.) He recommends that you maintain a cache of undeduplicated on the DL3D to avoid this penalty. Of course, this brings up a range of additional questions such as how much extra storage will the holding area require, how many days should you retain and what does this do to deduplication ratios?

The simplest solution to the above problem is to use forward referencing, but neither DD nor EMC/Quantum support this technology. EMC’s workaround is to force the customer to use more disk to store undeduplicated data which adds to the management burden and cost.

This reminds me of a classic quote from John “Hannibal” Smith from the A-Team:

I love it when a plan comes together!

What more confirmation do you need?

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.

Continue reading “The Fallacy of Faster Tape”

Categories
Backup Deduplication Restore

Trials and Tribble-lations of Deduplication

One of my favorite episodes from Star Trek was “Trouble with Tribbles.” In the episode, Uhura adopted a creature called a tribble only to find that it immediately started to reproduce uncontrollably, resulting in an infestation in the Enterprise’s critical business err spaceship systems. You can read a synopsis of the episode here or even better, watch it here. What does this have to do with restoration and deduplication? I’m glad you asked.

As I previously posted, the key driver in sizing deduplication environments and solutions is performance. This is because most solutions are performance constrained by deduplication. Like the tribbles from Star Trek, the risk end-users run is rapid growth in the number of deduplication appliances. It may seem easy to size the environment initially, but what happens if your data growth is faster than expected or stricter SLAs require you to reduce your backup and/or restore windows? The inevitable answer in most cases is more deduplication appliances. All of a sudden what seemed like one cute tribble (err, deduplication appliance) becomes a massive quantity of independent devices with different capacity and performance metrics. This large growth in machines will add complexity to your environment and will dramatically reduce any cost savings that you may have originally expected.

To avoid the above issues, you need to think about your needs not just today but into the future. The ideal solution is to purchase a system today that can meet your needs going forward. This stresses the importance of performance scalability and you must understand how this applies to any given solution.

In the world of Star Trek, Scotty easily beamed the excess tribbles to a nearby Klingon vessel. In the world of the data center, we are not so lucky. Besides who would be the unwilling recipient? Perhaps you could beam them to Data Domain?