You think you need one, but you're not sure. The number of models and combinations
of hardware and software are beyond confusing. So let's cut through the hype and get down to
business of buying tape backup.
What, you don't own a tape backup device? Now's the time to get one. Why bother? Simple:
Without backups, your data is living on borrowed time and your business could suffer.
Remember those customer records that were carefully typed in to some database? What would
happen if this information would disappear tomorrow? If there is any critical data that would
put your company out of business, now is the time to put some backup procedures in place.
Why specifically use magnetic tape for keeping a spare copy of your corporate data? Easy:
tape is the cheapest, most portable and most secure means of data storage. Buying a tape
drive is a relatively simple economic justification, since the price of the equipment is minimal
compared to the value of the data backed up. There are tape drives for any budget, from a
few hundreds to several thousands of dollars. And the procedures for doing backups can be
simple, once you figure out which configuration is suitable and what data you need to copy.
There are several things to consider:
1. What data needs to get backed up and when?
The hardest part about using backups is putting together a solid plan to backup the right kinds
of information at the right times. The goal is "something that is reliable and easy to use," says
Jeffrey Kunce, engineering systems coordinator for the Missouri State Department of
Conservation in Jefferson City, MO (314 751 4115 x 364). The department has a variety of
DOS, Windows and OS/2 computers connected on an IBM LAN Server network, along with
an IBM RS/6000 workstation.
You first need to calculate how much of your data changes over time. If your payroll data is
only touched every other week, then you don't need to make backups more often than that. If
your customer database is being updated every hour, then some sort of daily (or even
twice-daily) backups are called for.
Next you need to match your backup routines to these periods of change. A good general rule
of thumb is to schedule backups of network servers at night, when there is little other activity
on the network. "It is best to have the system backup scheduled for off-hours. That way most
users will be off the system," said Nate Van Der Weide, president of Computer Solutions,
Inc. a systems integrator in Iowa City, IA (319 351 7549). They have designed numerous
networks for many businesses.
"Our network backup typically runs from midnight until 2:00 am, and our operations are such
that no one is working during that time period," said Taylor Horst, information manager for
University of New Mexico Press in Albuquerque, NM (505 277 2346). The press has mostly
Windows PCs on a NetWare network.
Why are the wee hours of the night so desirable? Most backup programs don't get along well
with other network users: they usually skip files that are in use by other users and so the
more users active on a system during a backup, the fewer files that get backed up. This can
be trouble for database and electronic mail programs that tend to have lots of open and active
files all the time. "Cheyenne [Cheyenne Software Inc., Roslyn Heights, NY 516-484-5110]
provides a special option in ArcServe called the "deny none" version which backs up file
sthat are open and does not deny access to other users in the process. We've had to learn
which software and files can and can't be backed up while in use, usually by asking in-depth
questions to developers and through lots of testing," says Bill Lawrence, a network supervisor
at San Onofre Nuclear Generating Station of Southern California Edison, in San Clemente,
CA (714 369 2747). The nuclear plant has close to 3000 DOS and Windows computers
connected to several NetWare and Unix servers.
There are two distinct methods of making backups: incremental and entire system copies. The
former means that you make just a copy of all the data that has changed since the last
backup. This saves time and tapes, but it can be confusing if you need to find a particular file
from the backup that needs to be restored. The latter is easiest to manage (you just copy all
your data onto a set of tapes) but can take more time. "We do nightly incrementals and
weekly full backups, and then keep the tapes for a year," says Lawrence. "I try to stay away
from incremental backups because they are such a pain when attempting a restore. The
additional cost of the complete backup outweighs the effort and potential for a mistake when
attempting a restore from an incremental set of tapes," says Horst.
Finally, you need to calculate how much data (in terms of megabytes and on which servers
and desktops) is actually changing, and match the equipment to this load. "Choosing a backup
system isn't dependent on how many workstations you have, it's dependent on how much data
you have," said Van Der Weide. More on that in a moment.
2. What items do you need to buy?
Tape backup devices have three critical components: hardware, software and tapes. Depending
on what you purchase, your computing life could be easy or hard: different configurations can
be a bear to operate or a piece of cake. "Every system is different. It's difficult to know what
is best for the customer until we've spent some time disucssing their own data," said Van Der
Weide.
Let's first consider the actual tape drive hardware itself. While there are many different drive
manufacturers, you can narrow the field quickly by looking at how much data storage
capacity you'll need.
The less-expensive tape drives start with street prices around $200. These low-end drives,
such as those available from Colorado Memory Systems [Loveland, CO 303-669-8000], use
quarter-inch cartridge (QIC) tapes which can store between 100 to 250 megabytes of data.
More expensive models can cost a thousand dollars or more such as those from Exabyte
[Boulder, CO 303-442-4333]. These use digital audio tape or 8mm tapes that can hold up to
ten gigabytes' worth of data.
"For less than 300 megabytes, we recommend Mountain's FS8500 {Mountain Network
Solutions, Scotts Valley, CA 408-438-6650] drives. For backups between 300 to 800
megabytes, we recommend Colorado Memory System's PowerTape. And for anything more
than a gigabyte, we recommend Hewlett Packard's JetStore [Palo Alto, Cal. 415-857-1501]
digital audio tape drives," said Van Der Weide.
Tape drives can be connected to computers in a variety of ways: via the parallel port (as with
the Backpack), a special controller card that comes with the tape drive itself, or with standard
small computer systems interface (SCSI) controller cards. "For reliable performance, we stick
with name-brand controller cards such as Adaptec's," [Milpitas, CA 408-945-8600] said Van
Der Weide.
Besides the tape drive, a second item is the tape backup software itself. Sometimes this comes
included with the tape drive (such as those from Colorado Memory Systems), sometimes it is
a separate purchase. Software is probably the most important piece of the puzzle: all of our
corporate sources agreed that ease of use and reliable operations were two critical factors in
picking the right backup software.
Again, you can simplify your search by deciding which of two backup strategies you'll
persue: servers-only, or servers-plus-desktops.
Some corporations disavow some or even all of their desktop data in their backup strategy
and require users to store critical data on their network servers: "We currently backup hard
drives on some critical individual's desktops," said David Goodman, network systems manager
for the Solomon R. Guggenheim Musem in New York, NY (212 423 3658). The museum has
150 computers connected to four Novell NetWare servers. "However, we do provide our users
with network directories which are backed up nightly as well as a variety of utilities which
they can use at their own discretion." This means that the burden is on individual users to
move the data themselves, which doesn't always happen. "We provide each user with network
disk space for the storage of important files, and we backup these areas nightly," said
Lawrence.
Others have developed some kind of routine to backup some desktop data: "Critical data from
individual desktops is automatically copied daily to the servers, where it is backed up," said
Kunce. "For about half of our users, we move a portable Backpack [Micro Solutions, DeKalb,
Ill. (815) 756-3411] tape drive around to each machine on a rotating basis to do an entire
backup of their hard disk. This machine plugs into the parallel port on their desktop and takes
on average two hours," said Horst. Another solution is to load special software on each
desktop that works in conjunction with the network-based backup routines. "Cheyenne's
Arcserve has the ability to backup workstation disk drives from the network," said Van Der
Weide.
Some desktops can be difficult to backup, such as those running OS/2. "Many backup
products don't work with OS/2, but we've been using Christie Electronics Backup Software
for PSS successfully," [LOCO, ID TK] said Kunce. "It allows us to make a complete backup
of our OS/2 systems, including extended attributes and system files."
Other desktops can be easier, but require some clever programming. "I've developed several
programs that work with Central Point's PC Tools backup software," said Steve Eppley, an
independent microcomputer consultant in Pasadena CA (818 577 0365). Eppley has designed
a variety of networks for small businesses mainly using Artisoft's LANtastic operating system.
The four largest tape backup software vendors are Cheyenne, Maynard (now a division of
Conner Storage, Lake Mary, FL 407-263-3500], Palindrome Corporation [Naperville, Ill. 708
505 3300], and Mountain's FileSafe. Each offers both server-only backups and backup
software that also copies desktop data to a network-attached backup device.
How you do pick which product will work in your situation? Our users recommend reading
the trade publications and talking to your local dealers. "Maynard was recommended by our
local Computerland dealer," said Horst. "We read volumes of reviews from industry
periodicals. If something looks interesting, we install it in our office first, and then we can
feel comfortable recommending it to our clients," says Van Der Weide.
"We selected Cheyenne after lots of testing and vendor interviews. We knew what we wanted
and needed," said Lawrence. "However, Arcserve's documentation was bad to the point of
being humorous when we first bought the product."
The third item in the backup trilogy is the actual tapes themselves. Most of our sources
agreed on this issue: follow the tape drive manufacturer's recommendations strictly. "Hewlett
Packard recommends Sony tapes. We also use 3M for some applications. We haven't had any
problems with either manufactuer, so we haven't tried anything else," said Van Der Weide.
"We used a variety of tapes early on, but found that the tapes sold by Exabyte seemed to
work best for the longest period of time, and so we now use them exclusively," said Horst.
Lawrence in San Onofre also uses Exabyte tapes exclusively as well.
3. Where do you locate the tape backup device?
The tape backup unit usually has to be attached to some computer system. You have two
choices here: the tape drive itself goes either on an individual workstation or is connected to
one or more of your network servers. The difference is generally a trade-off between
performance and convenience. Workstation backups are slower but more flexible, since you
can move the backup device around. Server-based backups can be faster but more
troublesome if the server fails: "Problems with the server itself would mean you couldn't do
a restore without much hardware swapping and reloading software," said Horst. And, "if you
need to replace a cable or upgrade firmware on the controller card, you'll have to bring down
your server," accoding to Goodman.
Intel [Hillsboro, Ore. 800 538 3373] has an interesting twist on this: they manufacture a
complete tape-drive server that comes with its own computer system that includes the tape
drive, backup software from Cheyenne, and network card. Storage Express is expensive,
however (there are various models, beginning around $8,000). You merely attach it to your
network and load the appropriate tapes. "It is a stable product and all of its components are
integrated into one unit. Intel also takes full responsibility for supporting all the various
components," said Goodman.
4. What about service and support?
You would expect your tape backup device to work reliably, but that isn't always the
situation. Our users interviewed mentioned many problems that they had getting their tape
backup devices to function consistenly. "When we encountered a problem with backing up
one particular machine with our Backpack, Microsolutions shipping us a fix that we were able
to install and fix the problem. Turns out we were running an older unit," says Horst.
UNM Press had to go without their Conner/Maynard tape drive two weeks while the vendor
tried to fix it. "for whatever reason, they couldn't fix our unit, and instead of a refurbished
unit we got a brand new one. This was after our warranty had expired. I believe they were
honest and did the best they could," said Horst.
Missouri's Kunce has had a different experience with Maynard, however. "Our DAT drives
from them have been nothing but trouble. Something goes wrong at least once a week. We
tried moving the backup unit from the workstation to the server, using tapes by different
manufacturers, and finally were told to change our interrupt setting on the controller card.
After making this last change things seemed to go more smoothly. But I don't know why we
had to go through four months of grief for such a simple solution," said Kunce. He contrasts
this experience with the backup device on his Unix workstations: "Our 8mm tape drives that
came with our IBM RS/6000 workstations don't have much support, but not much goes wrong
with them either," says Kunce.
The Guggenheim Musem had all sorts of problems with their Gigatrend/Cheyenne system and
was continually calling Gigatrend for support. "I would like to think that any technical
support department would be able to see a 'red flag' when the same organization was calling
week after week with the same problem. Gigatrend never did," said Goodman. As a result, the
museum switched to Intel's Storage Express system for their backups.
Getting technical help can often be an issue, and Cheyenne has become infamous in the
computer industry for clogged support lines. "A call to Cheyenne has the requisite half hour
wait on hold," said Lawrence. One method is to try alternative paths to the telephone: "We
have the best luck contacting Cheyenne through Compuserve," said Van Der Weide. "The
Colorado Memory System electronic bulletin board is a good source of tips," said Eppley.
5. How do you test your backups?
The best backup systems in the world include some form of testing the tapes to make sure
that the data is actually written to the tape correctly. This is called a test restore: "Every 30
days try to restore some files
from your tape drive to verify its operation. If you have a hard time
remembering to test a restore, try it after every cleaning," says Van Der Weide. "
The biggest problems we've had with data loss is not that the files couldn't
be restored from tape, it's that they weren't backed up in the first
place--mostly due to user errors."
One simple aid is to use an option on most backup software that verifies data written to tape.
While this can increase the amount of time that a backup takes, "I have found that if the
verify pass shows no errors then the tapes are readable," says Eppley.
At one of my former employers, we used the verify option but didn't really pay careful
enough attention to what we were backing up. Turns out due to a software bug (we were
using Maynard's software), several tens of megabytes of files were being skipped for several
months' worth of backups. Only when we tried to do a restore from this particular void was
the bug discovered.
Cleaning? Tape drives are delicate machines and develop dirt over time. "Follow the
manufacturer's recommendations for cleaning your
tape drive. This is very important. Tape drive cleaning kits are available
and will save a lot of future problems," said Van Der Weide. "Some high-end tape drives
eliminate this guesswork by automatically notifying you when a cleaning is needed," said
Lawrence.
6. Where do you store the tapes?
Once the backup tapes are created, you also need to figure how they will be stored. "Off-site
storage must be a part of any organization's disaster recovery plan. You should build it in as
part of any managed tape rotation scheme," says Goodman. This means that you put in place
a plan to move tapes off premises in case of fire or natural disasters, so that you'll still be
able to recover your data in the worst of circumstances.
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David Strom
Port Washington, NY 11050 USA
US TEL: 1 (516) 944-3407