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Is tape backup the best option for my small, but growing business?
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It certainly can be, but it depends on what your business uses computers for and what needs to be backed up. It’s possible that using a CD/DVD backup will be more than sufficient to meet your needs unless, of course, you’re looking for something that will handle your backups automatically without any thought or intervention on your part, regardless of the expense.
To better answer this question, you’ll need to spend time planning your backup needs so that they suit your particular business, rather than depending on a general strategy used or suggested by others.
Tape backups can, indeed, be the best option for your business, but you won’t know unless you determine what your needs are and how you want to handle them. Only then can you decide what backup media will work best for your situation.
Windows cannot read tapes natively as easily as it can CD/DVD/Blu-Ray/HDDVD discs. This makes restore time a lot easier when you are not dealing with a tape.
Note: Don’t forget that you’ll need to take at least one tape offsite on a regular basis or you could risk potentially loosing your data in case of a disaster such as theft, fire or flood.
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| Q. |
What are the benefits of tape backup?
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There are several benefits to using tape backups. One
of the main reasons businesses use tape is that it is relatively inexpensive to
maintain, when compared to replacing the entire infrastructure of a legacy
system for a newer backup system.
Businesses also use tapes for the reason that tapes can be used over and over
again, by rewriting over them at backup time. This benefit can also be negative as tapes do have an expiration date which could lead to data corruption
or un-restorable backups. Probably the biggest benifits of tape backups, are that the actual tape can store a high capacity, the data is automatically compressed via hardware compression, and the tape can easily be taken offsite. If there is a fire, and if you remembered to take your tape with you, your data will be safe.
For larger companies, tape libraries can also be purchased which automate the process of using tape drives.
Overall though, tape is not ideal because of the very long restore time, and finding the actual tape that you need can be difficult. A large percentage of tape backups fail to restore when the data is needed.
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| Q. |
What are the downsides of tape backup?
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The typical tape backup is only done once a day. As a
result, more data can be lost depending on when exactly the disaster strikes.
For example, if your computer crashed at the end of the day, you would have
lost all the days work. This reality can be better combated by having an
incremental or continuous backup that runs throughout the day instead of once a
day. Continuous backup is not possible with tape backups.
Another issue that most people aren't familiar with is that tapes actually wear
out and expire in time, due to the continuous writing to them. Tape
expiration can lead to unrecoverable parts of the tape or worse, a totally corrupted
and unreadable backup.
A third downside to lower end tape drives is the lack of automation and high
reliability on human intervention. These tape drives require an actual
person to insert a tape daily and require them to remember to change the actual
tape daily or when the tape has reached its storage limit to complete the
backup. This human interaction is very time consuming and has a high potential for human
error.
The last and maybe biggest downside to tape is the lack of tape indexing.
This means that at restore time, you can’t automatically skip to a particular
point in the backup on tape to get to where the data you need is stored.
This can severely slow down the restore process, as you have to go through the
entire tape to get to each particular data point.
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| Q. |
What is direct attached storage (DAS)?
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Direct Attached Storage (DAS) is a device that connects directly to the server or computer that you are backing
up from. If you are backing up from a different computer from the DAS attached computer, you cannot access the DAS. In this case both computers would need their own DAS.
A common misconception is that you cannot backup LAN computers when using a DAS device. This is possible and very common. You can backup any LAN computer just as long as the data is being pulled onto the computer where the backup client is running from.
A DAS device cannot be accessed from LAN computers, so the backup client on the local machine must be pulling the data (as opposed to the data being pushed by the LAN computers).
DAS is different from network attached storage (NAS) and storage area networks (SAN).
DAS can be a tape backup device, a USB external drive that is not mapped, or any other device that is not accessible on the network. |
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| Q. |
What is an autoloader?
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An autoloader is a multiple tape storage device that
automatically changes tape cartridges using a robotic mechanism. Autoloaders provide a streamlined and
uninterrupted backup using tape. Cartridges can be loaded sequentially or in
any order that you specify.
Autoloaders save IT professionals time by eliminating the hassle of having to
manually remember to load, eject or monitor free space of a tape at backup
time.
Autoloaders are usually expensive and generally contain one tape drive, a
‘robot arm’ (to change tapes), and up to 10 tape cartridge slots.
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| Q. |
What is a tape library?
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In reality, a tape library is a set of multiple autoloaders put together with software to act as one unified backup system. A tape library generally contains multiple tape drives, multiple cartridge storage slots, and multiple ‘robots’ which are used to automatically load/eject tapes.
Tape libraries are generally very large and come at a high price. They can be found in large disaster recovery centers and data warehouses and are typically used by enterprise sized clients. |
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| Q. |
Do I have to change my tape every day?
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This depends on your data retention needs. If you need
to only keep the latest copy of your data then you can overwrite your old data
with new data and keep the same tape in the drive. This method will lead
to degradation though.
If your tape has enough storage capacity, you could use differential or
incremental backups and append the latest data to backups already on the tape.
It's always a good idea to keep your data offsite. For tape
backups, this means taking the tape to another location; therefore, your tape changing policy should take this "offsite concept" into account.
An example of a good policy is to have 3 tapes.
Keep one tape with a full backup of your data (Label this Tape #1).
Then perform differential backups with rotating tapes (Tape #2 and Tape #3) once
a week. Every other week, you would
re-use the other tape (Either Tape # 2 or Tape #3). Your full backup tape (Tape
#1) would not need to be updated very often.
The only time you would do this is if your differential backups are
getting so large that they cannot fit onto a single tape.
In the above example, for your first full backup, you may
have to use several tapes instead of just one.
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