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
Mac, $699
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
- VXA-1,
$1,049
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).
