Exclusive: Maxxan rides the virtual tape

SVT200 VTL blade brings new flexibility to backups

Maxxan Systems, a relatively new storage company, is pioneering the field of intelligent director-class switches with its flexible MXV320. (See InfoWorld's review of the MXV320). A master of adaptability, the MXV320 can load in its capacious chassis a variety of blades and offer storage services such as data mirroring, file serving, and virtualization. (To read more about the Maxxan SANe architecture, see "Complex, ergo simpler.")

Among the MXV320’s application-focused blades are the SA200f blade, the centerpiece of the system’s storage provisioning and disaster recovery, running IPStor software from FalconStor, and NetBackup DataCenter from Veritas. There’s also the SG210m blade, which is Maxxan’s NAS gateway, running Windows Storage Server 2003.

Recently, Maxxan unsheathed yet another blade: the SVT200. The focus is virtualization but this time targeting tape drives, specifically a VTL (virtual tape library), rather than disk volumes. (Maxxan also offers a standalone appliance with similar functionality, called the SVT100.)

A VTL is exactly what the name implies: a software-generated object that simulates the behavior of a tape library, including robotics, cartridge slots, and tape drives for the benefit of OSes and backup apps. Because it emulates a real library, deploying a VTL has a negligible impact on existing job scripts and procedure and usually offers tools to automate moving data to real media.

The SVT200 exemplifies how the total can be more than the sum of its parts. Merging the excellent Virtual Tape Library software from FalconStor and the flexible architecture of the MXV320, Maxxan has put together a VTL solution that competing products will struggle to match.

The synergy between appliance and blade solution makes possible centralized, tapeless data protection for remote sites. As far as I know, no other vendor can make that boast. Unfortunately, there are some limitations, the most severe being that it supports only Windows servers, and Solaris on a limited basis.

The SVT200 has two RJ45 management ports and 10 2Gbps FC (Fibre Channel) ports, more than enough to connect the real tape library, the backup server, and the storage arrays used for staging the virtual library. I also noticed two GbE ports that are unused at the moment because this release supports only FC connections.

I was first struck by the ease of deploying the blade: I slid the card in one of the free slots of the MXV320, made the physical connections, set the FC zoning, and I was ready to go.

It was time to define my virtual library using the VTLC (VTL Console), the VTL software’s GUI. The software provides functionality such as creating the simulated tape library, allocating disk space for tapes, and assigning the library to the backup server.

Virtual Library Setup

If you wonder what tape libraries the SVT200 can emulate, think big ADIC, IBM, Quantum, and StorageTek models mounting major tape drives. My real library was a StorageTek L20 with two Quantum SDLT 320 tape drives, so I chose the same model and same drives for my virtual library.

Interestingly, you can create a virtual library choosing any model, even if you don’t have a consistent physical library. This option comes in handy to centralize backup operations. For example, you can back up to virtual tape at a remote branch, then transfer those images via the WAN to a central location.

Back to creating my virtual library, I cheated on the number of drives, adding six instead of two. Why cheat? Having more virtual tape drives, you can run multiple backups at the same time or generate multiple streams for the same backup. Either way, backups finish faster.

My next step was to define virtual tape media to use for backups. Appropriately, the GUI let me choose how much disk space to allocate for each reel which facilitates adjusting their size to actual backup requirements.

In addition, I was able to define an increment factor for each reel and to set a maximum size. The VTLC has these and numerous other options to help ensure that virtual tapes will be consistent with real tapes.

For example, I assigned a bar code range to my virtual reels, which helps in making error-proof transfers to actual media. Moreover, those transfers can be triggered manually or, if your backup software supports it, automated with the auto-archive option.

Managing Disk Space

The comprehensive and well-thought-out features of the VTLC GUI impressed me. They should cover the requirements of most datacenters and help make a transition to the world of virtual tapes easy.

Lastly, I was able to decide where to store the tape images, choosing from the disk devices available to my zone, which helps in managing disk space and selecting faster disk devices for backups.

The final step was to assign my newly minted library to my Windows 2000 backup server, which can be accomplished easily by typing the name of the server into a VTLC screen.

Next, I moved to the Windows 2000 backup server, where I had Veritas NetBackup already installed. Whatever your choice of backup app, on a Windows server you should be fine: Maxxan’s supported list covers them all. However, you have sensibly fewer choices for Solaris backup servers.

A quick check of Windows Device Manager showed the library and my six SDLT 320 tapes. I started NetBackup that also recognized library and tapes without problems.

Backups and restores ran faster, without a glitch, on my virtual library, but actual rates depend on what kind of disk drives you use.

Choosing which disk drives will simulate virtual tapes is a critical decision. Faster disk drives mean faster backups, but you will also need plenty of capacity.

For my virtual tapes, I had an array of eight, very fast Seagate drives that I thought were probably overkill for simulating tape drives. In a production environment, I would probably use multiple slower and larger drives in parallel, speeding up my backups over multiple virtual tapes.

Therefore, I was surprised when my initial backups would not go faster that 12MBps to 13MBps. I suspected the configuration of the array hosting the virtual tape was the cause.

Adding another array, this one configured as just a bunch of disks, confirmed my suspicion. After creating a new VTL on that array, I saw the backup speed jump to 42MBps on a single virtual tape — without compression, which more than doubles the maximum transfer rate expected for a Quantum SDLT 320.

Actual performance obviously depends on what disk drives you use to support the virtual library, but one advantage the Maxxan solution has over some competitors is that you have full control over that.

By the end of my evaluation, I found there was only one thing that I did not like about the SVT200: little  support for UNIX although you can run it with Solaris backup servers. Maxxan will probably correct that limitation in future versions. If you can work around that, the SVT200 can dramatically cut your backup windows, making your data protection jobs faster and more reliable.

InfoWorld Scorecard
Scalability (20.0%)
Performance (20.0%)
Management (20.0%)
Ease of use (10.0%)
Value (10.0%)
Setup (10.0%)
Interoperability (10.0%)
Overall Score (100%)
Maxxan SVT200 9.0 9.0 8.0 9.0 9.0 8.0 6.0 8.4

Copyright © 2004 IDG Communications, Inc.

InfoWorld Technology of the Year Awards 2023. Now open for entries!