Howdy – I am the publisher of the above title and I like to hold virtual book readings. (Also – my SBS 2008 book is now here!)
So here is a passage:
Betting on Backup
I’m preaching to the choir here, but it bears repeating that your server, no matter how robust, needs to be backed up on a regular basis. Traditionally, most servers have included some sort of tape backup for archiving information nightly. But the rapid evolution of optical technology has witnessed a spirited adoption of single-layer and dual-layer DVD writers, and the proliferation of inexpensive hard drives has also encouraged high-capacity external drives that connect over USB 2.0 or IEEE 1394 buses. What backup device you choose should depend on your storage needs.
Note that backup matters are discussed further in Chapter 15 of this book (including discussion of advanced disaster recovery). The introductory SBS book of this series, Windows Small Business Server 2003 Best Practices, discusses the basic SBS 2003 backup routine in Chapter 11. You can purchase that volume at www.smbnation.com.
Sticking to Tape
While groundbreaking advancements in tape backup devices are few and far between, tape remains one of the most convenient mediums for storing valuable information. It costs less per gigabyte than optical discs and removable hard drives, and it often stores more data to boot.
The most economical tape drives are of the Direct Attached Storage (DAS)
variety; as opposed to LAN-based solutions, they physically connect to your
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server. DAS devices are characterized by simple manageability, broad software support, economical acquisition, and peak utility in smaller offices.
Within the family of DAS tape drives there are a number of tape technologies, spanning a broad array of performance and price points. One of the most popular technologies, with capacities up to 40 GB, is the Digital Audio Tape (DAT) format. Unfortunately, DAT drives interface exclusively with SCSI controllers, a factor that adds to their cost. They also top out at a data rate of 4.8 MB per second, which is relatively slow next to other more advanced designs. For example, the Digital Linear Tape (DLT) format is characterized by more capacity, faster transfer rates, and enhanced reliability. In its most advanced form, DLT is able to hold 70 GB of compressed data moving at 20 MB per second. But like DAT, DLT is limited to use with a SCSI controller.
Perhaps a more attractive solution is an external USB 2.0 Advanced Intelligent Tape (AIT) drive that balances reasonable capacity (90 GB, compressed) with moderate performance (roughly 4 MB per second) and a price tag under $1,000. Just remember that tape is almost exclusively an archival medium, so pay particular attention to specifications such as access times, which often range right up to 30 seconds. Compare that to the millisecond ratings for external hard drives and it quickly becomes apparent why the two mediums each excel in their own different respects.
CD and DVD writers don’t boast the flexibility of a tape drive, but they do facilitate quick and easy backup for document folders and multimedia files. Due to the extreme rotational velocity of 52x CD-R drives (the fastest available), CD writing technology probably won’t evolve much beyond its current speed. DVD±R/RW drives continue to accelerate however, managing to write 4.7 GB of information in just over five minutes. If you’re looking for a versatile medium that enjoys compatibility with an array of other devices (try plugging that tape cartridge into your laptop or a client’s workstation), a DVD writer might be the most economical backup solution.
BEST PRACTICE: If you’re looking for true portability and aren’t
necessarily concerned with capacity, invest in a USB flash drive—
one of those little keychain devices that hold between 32 MB and
CHAPTER Chaper 2 1 ☛ So Understanding You Want to Hardwre Be an in SMB the SBS Consultant?!?! Environment
1 GB of data. I carry one with me everywhere; it’s great for storing documents, music, and the latest driver updates. While it isn’t an answer to your SBS backup problem, you never know when the extra storage might come in handy.
The freshest idea in the optical drive market is the dual-layer DVD. Capable of storing 8.5 GB of information, many of the dual-layer drives are priced under $100. Unfortunately, media is still rare and prohibitively expensive, though proliferation of DVD+R DL hardware should help drive the price down over time. Don’t count on using a series of dual-layer discs for running a complete backup; rather, it’s a technology to keep your eye on for now.
External Hard Drives
The championing of high-speed peripheral-to-PC interconnects, such as USB 2.0 and IEEE 1394, has enabled an impressive array of external hard drives that feature excellent performance, massive capacity, availability through random access (for when you need to find just one file), respectable portability, and best of all, a reasonable price tag.
A number of tape drives have also made the jump to USB connectivity, which is convenient for servers that don’t have SCSI controllers, especially entry-level servers. However, I maintain that an external hard drive together with flexible backup software is a good alternative to tape. I use Seagate’s 160 GB external repository for weekly backups of a 146 GB Cheetah 10K.6 SCSI drive. Using Dantz Retrospect 6.5, I’m able to run automated, incremental backups of all files, including those that are in use. Even the network clients I select are monitored and protected by Retrospect’s network support. The large capacity means that the backups all run unattended and without the need to rotate media, as I’d have to do with a tape drive. Further, at the greater than 50 MB per second transfer rate, incremental backups only take a few minutes.
Harry Brelsford, CEO at SMB Nation (www.smbnation.com)
MBA, MCSE, CNE, CLSE, CNP, MCP, MCT, SBSC (Microsoft Small Business Specialist)
PS – my Small Business Server 2008 (SBS 2008) book is now here!