You've been hearing a lot of talk in the industry about this new technology that allows you to realistically eliminate your dependence on tape-based backups and go completely to a disk-based system. But you're unsure of what that means to you. Your sentimental side sees those tape backup systems that you have grown and nurtured into their senior years: they are hard-working and reliable; they come to work each day and do exactly what they are designed to do. Even though they are not the fastest performers, they just keep chugging along. You also have a lot of history with them that you want (or have) to maintain. Maybe you should look at that new tapeless technology and just get rid of them, but you cannot bring yourself to do it just yet.

With each passing day, you know the decision has to be made, so you finally pick up the stack of trade journals on your desk and start looking at Virtual Tape Library (VTL) technology. You close the door to your office so your collection of tape libraries that have performed so well for you through the years do not see you researching how you can replace them. You are amazed by the different versions of VTLs that are out there and the many options available.

Fear not! You have the advantage of being in a market where the technology is advancing faster than in any other market, and VTL devices are becoming more and more accommodating for use in enterprise data centers with a variety of systems.

I'll talk about some of the most common and most effective strategies for the implementation of VTL technology in your data center so that your entire environment can realize the many advantages a VTL has to offer.

VTL Advantages

First, you get the opportunity to choose how much or how little you want to utilize tape for a backup and, more importantly, a recovery media. You should keep in mind that a tape-based backup and recovery process has a high probability of failure in the backup process or, worse, during a recovery.

Second, disk is simply faster. As for backing up to disk, the speed of tape (LTO3) can be comparable to disk, but nothing compares to the speed of data recovery from disk. Because the recovery process is critical to getting your company back in business, your focus should be on this capability first; then you can worry about the recovery.

Third, did I mention that you could eliminate tape?

Depending upon the VTL technology you choose, you get a variety of other options from which you should choose wisely; a wrong decision now could cost you more in the future. You want to choose a solution that provides a solid foundation you can build on as your organization grows.

Implementation in the System i Data Center

Since your data center is a picture of growth, where you likely have systems that have been acquired to serve specific purposes, the variety of connection technologies can range from SCSI to fibre on your System i and from SCSI to fibre and even iSCSI on the open systems environments. Since you also want to realize the benefit of the VTL technology across your other platforms, you may be concerned about how the technology you choose can fit without a heavy investment in network conversion devices or replacement technology.

As mentioned, the VTL technology is advancing. VTL vendors know that they need to be accommodating of heterogeneous environments, and some have risen to the challenge. You should look for vendors that work closely with the System i backup application vendors so that you know that ensuring integration with the System i is being done with some specific System i expertise.

Implementation Scenario

One of the best things about VTL technology is that the quality vendors have designed their solutions to essentially be a plug-and-play device you place it into your backup network, and away you go. The better VTL vendors can have you installed and operational within a few hours. You will, however, have to invest time in configuring the system for your specific use, and you should look to a vendor or a vendor partner that can assist you in that effort.

Do you remember your beloved tape devices that you were so afraid of offending by considering a VTL? Well, you have something for them also. A few of the VTL vendors in the marketplace offer the ability to continue the utilization of these pieces of equipment by having the ability to do a true disk-to-disk-to-tape process. You gain the VTL advantages and still have the ability to retrieve data on the old media. Every CIO out there knows that this is required by law and that the inability to do this could result in fines and/or jail time.

At the beginning of your design, you must first think about what is driving your decision: cost or productivity. Depending upon your answer, you can go a couple different directions.

If your System i is currently utilizing a SCSI connection to your tape device and you still know that your gradual progression will lead you to a fibre or even iSCSI technology, there are VTL vendors that supply this capability. With the leading VTL vendors, the implementation is as easy as plugging your System i into the VTL along with any other devices necessary. You can then also utilize your tape devices after the VTL device is installed.

An important note here is to ensure that your backup application has been proven to work well with the VTL technology and will still control the virtual device along with the physical devices.

This implementation allows you to avoid the cost of converting your System i to a fibre tape controller.

If you are lucky enough either to have fibre connectivity to your iSeries already or to be able to afford the cost of conversion to fibre, you can implement quickly and in conjunction with iSCSI systems. This configuration gives you tremendous advantage because the VTL can perform at its top-rated speed and provide you the best return on performance possible.

In both of the above implementations, no matter what the connection technology requirements are, a VTL can be implemented so that your data center can benefit from the technology.

Other Important Points Regarding VTL Technology

The ability to connect into your environment is one critical feature for defining a VTL purchase, but other features need to be considered and deserve to be mentioned.

• Integration with a System i backup application—Very few VTL vendors actually integrate well with the System i, so it is critical to have a configuration that has been tested and proven with the System i.
• Scalability—What is your growth plan for backup data growth? You need a system that can offer you ease of growth and preferably incremental, worry-free expansion of disk capacity.
• Encryption—VTL technology exists that offers the ability to encrypt the data going to tape or being replicated to another VTL device.
• De-duplication—This technology is one to watch, and anyone not preparing for an implementation is possibly overlooking a very valuable capability. In some VTL technology, a 10:1 and up to 25:1 data storage reduction ratio can be realized through the removal of duplicate data. You will want to make sure this is a post-backup process so you do not interfere with the backup window.
• Data Replication over IP—In today's world of disaster recovery, this capability a critical. If the desire is to eliminate tape, data replication over IP is a necessity.

The Best of Both Worlds

In summary, don't worry about hurting those old, dependable tape device's feelings; you can continue to get value from them even if the new VTL technology is implemented. It is, however, key to ensure that the connectivity capabilities exist with a VTL product and that both the VTL supplier and the provider of the backup and recovery application being utilized have a history with the System i.

Lon Gretillat is the Vice President of Business Development for LXI Enterprise Storage in Mason City, Iowa. LXI is the premier provider of enterprise backup and recovery solutions for the System i marketplace. LXI is a strategic partner of FalconStor Software and distributes the FalconStor VTL with the LXI Media Management System.

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