For a couple of months now, I've wanted to write the story of my adventures setting up a backup and restore infrastructure for my small network of three servers and four clients. But I had hoped to be further along with my project. Thus, this column is part 1 of the story. I began the work in late spring. For some time, I've recognized that although I give my clients good advice—back up, back up, back up—I hadn't taken that advice seriously enough. So far, I'd been lucky. I hadn't experienced a significant disk-related failure or a major virus outbreak. However, knowing that my luck might run out, I decided to remedy the situation. My goal is to create an inexpensive backup and restore system with reasonable performance that can support all kinds of Windows computers.
I was attracted to helical-scan tape drives because of their capacity. Last year, some systems featured 35GB tape drives, this year some feature 50GB tape drives, and next year apparently we'll see 75GB tape drives. I got a tape drive with a 50GB capacity—enough to back up my entire network. I also got a demonstration version of Computer Associates' ARCserve to try as the backup software. Although I found ARCserve feature rich, it didn't seem optimized for the small tape unit I was trying. On the tape vendor's advice, I switched to Dantz's Retrospect.
Retrospect is an old friend from my Macintosh days. Dantz has totally rewritten the program. Retrospect is also feature rich, and although it isn't well-known in the Windows storage community, it's well worth a look.
With the tape drive attached to one of my servers, Voyager (a Dell PowerEdge 2400 system), I backed up my network—although with a little difficulty. Voyager runs Windows 2000 Server. The tape drive had a beta driver that kept losing its place on the tape and freezing (not something that builds confidence in a system that is supposed to be there when all else fails). So I abandoned that tape drive and got another. (You've probably noticed that I haven't mentioned the first tape drive's vendor or model number. I suspect that the drive works fine on Windows NT Server 4.0, and I'm sure the vendor will fix any driver problems.)
The second tape drive is an Ecrix VXA-1 with a 60GB tape capacity (for more information, see the link listed at the end of the column). Ecrix's technology writes data in packets to the tape with cyclical redundancy check (CRC) code that addresses each 64-byte packet of user information. This error correction makes the tape drive highly reliable. (The tape drive is also rugged: In one demonstration, Ecrix boils its tape drive in water—and it still functions.) In addition, the tape drive's speed is variable; the tape drive can match its tape speed to the rate of the incoming data. Variable tape drive speed means that Ecrix tape drives can be built without the mechanics required for backstreaming, which simplifies the mechanism and reduces the cost.
With the Ecrix tape drive, I achieve speeds of 50MB to 75MB per minute on a 100 Mbps Ethernet network. Compared to the DLT 7000, which is somewhat of an industry standard for enterprise tape backup, the Ecrix tape drive offers about 80 percent of DLT 7000's capacity and speed at about 25 percent of the cost. (See John Green's Lab Reviews, Ecrix VXA-1, Windows NT Magazine, December 1999.)
Let me preview the second part of the project. In the next few months, I will replace my Small Business Server (SBS) server on Reliant (a 366MHz clone system) with SBS 2000. I've decided to use a bunch of disks in the PowerEdge 2400 server to create mirrored volumes on that RAID setup. I'll back up the RAID drive to my tape setup. (No more network backups for me.) The system will give me two backup levels, one mirrored (or nearly so) for immediate problems and another in historical/archival format on tape.
My next search is for software that will let me mirror my drives on the backup server. If any of you can suggest software that will let me do this with a Windows system, let me know.