Home and Small Network Backup Solutions
Dan Knight - 2000.02.11
I've preached it regularly: Backup is a crucial part of safe computing. It makes you ready in case your drive crashes, you get a nasty virus that trashes important files, your computer is destroyed in a fire or natural disaster, or you inadvertently make a real mess of a crucial file.
The best backup solution depends on your needs. Specifically, the most important questions is this: How much data do you have to back up right now?
At home, I have about 4 GB on my primary computer and maybe 1 GB on my server. My oldest son has pretty well filled his 2.1 GB drive. The other three have fairly full 230-270 MB drives on their 6100s. And then there's my wife's PowerBook 150 with less than 120 MB of data.
Add it all up. I've got somewhere around 8 GB of data to backup immediately - and that will only grow. My rule of thumb* is that your backup set (one or more tapes or disks) should be able to store twice as much data as you have to back up. In this case, I'd be looking at something with 14-16 GB total storage.
Here's where you need to pay attention: Some people quote tape capacity assuming 2:1 compression, while others quote native (uncompressed) capacity. Don't trust those 2:1 figures; they tend to be overly optimistic.
Years of running backup show that compression increases media capacity by perhaps 30-40% on average (35% is a safe figure to work from). This means a basic storage set for use on my home network should have at least 10 GB native capacity, which will provide 13-14 GB.
Why so much capacity? Because you should back up regularly, and it's much more efficient to back up only files that have changed and append them to an existing backup set than it is to do a full backup every day, week, or month.
Because of the amount of data I'll be backing up, it's easy to rule out Zip drives - we'd be working with 100 disks using my current Zip drive ($800 in media!) or 40 disks if I upgraded to Zip 250. That's too much disk shuffling. The same goes for anything with under 2 GB native capacity.
At the bottom end for drive price are the Jaz, ORB, and DVD-RAM drives. The following prices are from the APS catalog when possible, since I have several copies readily available. Exact prices will vary by vendor. Total cost is for drive and enough media for two 10 GB (native capacity) storage sets.
- ORB, $230
media $40, 2.1 GB native capacity
total cost: $520
average rated throughput: 732 MB/min.???
- APS DVD-RAM, $500
media $25, 5.2 GB native capacity (2.6 GB per side)
total cost: $600
average rated throughput: 80 MB/min
pro: random access for fast restores
con: must flip disk every 2.6 GB
- Iomega Jaz, $350 w/ one disk
media: $100 in quantity, 2 GB capacity
total cost: $1,250
average rated throughput: 444 MB/min.
Tape drives provide much higher media capacity, some up to 30 GB per cartridge. Here I am only considering sub-$1,000 solutions that store at least 10 GB (native) on a single tape.
- NS-20, $500
media $45, 10 GB native capacity, Travan
total cost: $590
average rated throughput: 50 MB/min
con: I've heard Travan is noisy
- ECHO30 for
media, $40, 15 GB native capacity
total cost: $779
average rated throughput: 120 MB/min
- APS HyperDAT III, $850
media $23, 12 GB native
total cost: $898
average rated throughput: 60 MB/min
media: $30, 12 GB native capacity
total cost: $1,109
average rated throughput: 360 MB/min
Three of these options are very affordable - ORB at $520, DVD-RAM at $600, and NS-20 at $590 total cost - so these are the three I'll concentrate on.
Much as I like the idea of a double-duty removable media drive, and nice as it would be to use DVD-RAM to move files between home and work machines, the simple fact is that I would grow to hate backup while swapping disks as they fill up. It happened in the era of floppies. More recently, it happened with Zip 100 disks. With 2.1-2.6 GB native capacity, I don't think it would be too long before I grew to hate it with ORB and DVD-RAM, too.
Which brings me to NS-20, a tape backup solution that uses Travan quarter-inch cartridges with 10 GB native capacity and has hardware data compression. These are available from several sources for about $500, so it comfortably fits my budget, so unless I can find a standout price, I'll probably buy from APS, a company I've been dealing with for years and years.
Your mileage may vary. If you have a few older Macs with smaller hard drives, another solution may better fit your needs. And if you're backing up a large network with lots of data, look at DLT and AIT, which have positively huge tape capacity.
Most of all, if you're backing up a network, you'll want to have Retrospect backup software along with a copy of their client control panel for each remote machine. There may be easier backup solutions for a single computer, but nearly eight years of using Retrospect has convinced me it's the best thing going for Mac network backup (and it can even back up Windows computers on the network).
* As an information systems manager by day, I've been overseeing backup for over seven years. Always buy more capacity than you need today. Always.
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