Backup Options

In this section, the different types of backup options will be explored, and we’ll discuss the advantages and disadvantages of each backup option.

Tape

Tape backups are historically the method of backup. Tape drives have been in heavy use since the 1960s, and they are still around today. The main advantage of tape is that it is fairly durable, and tapes have the most space of any type of removable media. Tape backups have been on the way out, though, and there are many reasons for that.

Disadvantages of using Tape:

• Tapes are expensive for the amount of storage they provide. Historically, tapes were relatively huge when compared to hard drives, and tapes were cheap on a $ to GB basis. Now, they are one of the more expensive options. The main reasons they are still in use is momentum and the fact that most other alternatives top out at 10 GB per disk.


• Tapes are slow. The fastest drives (and these drives are typically $1500+) write at about 16 MB/s, but most of the low-end drives are 1-5 MB/s, which is like 1-4x DVD-R write speeds.


• No random access. This means that it is slow to just grab a file or two off the tape. The drive may spend a minute or two seeking to the part of the tape where the files you want are.


• Tape drives can only realistically be used for backup. No one uses tape to transfer files from one place to another, and most computers don’t have tape drives anyway. So the money you spend on tape can’t be used for anything else.


• Special software is required. Either you must use whatever comes with the drive you buy, or you’ll have to buy additional 3rd-party software. You usually will have to use that same software to write to and read from the tape.

One thing to note about tape is that manufacturers always report the compressed storage space, which is double the actual storage space. An example of this is the DAT 72 format. Manufacturers tout the 72 GB storage space, but in reality, there is only 36 GB of storage space on the tape. They assume that compression will average to double the amount of data you can store, but that just isn’t the case any more. Movies, music, pictures, and zip downloads are already compressed so the tape software can’t compress them further.
Because tape drives have begun falling out of use with the average home/SOHO user, the cheapest options have been dwindling. DDS3, DDS4, and DAT 72 are the most common formats for the low/mid range market.

• DDS3: 12 GB uncompressed space. $5 tapes, $200-300 drives, 1 MB/s


• DDS4: 20 GB uncompressed space. $7 tapes, $300-400 drives, 3 MB/s


• DAT 72: 36 GB uncompressed space. $25 tapes, $400-700 drives, 3 MB/s
  

CD/DVD

CD writers can still be used for backup, but since DVD is nearly a perfect drop-in replacement that gives much more storage space (650 MB vs. 4.5-8 GB) and speed (7 MB/s vs. 10-20 MB/s) for basically the same amount of money. There just isn’t much reason to back up to CD any more if you are willing to plunk down the $50 or less for a DVD+/-R/RW drive.
DVD is the most cost-effective form of backup, depending on how fast your data changes. Single-layer 4.5 GB discs are about $30 for a 100-pack, so that is 450 GB of storage for $30. Dual-layer 8 GB discs are still much more expensive (about $2-5 per disc), but the price has continued to drop. If you have between 4.5 GB and 8 GB of data, it can be worth it to back up to a single dual-layer disc rather than having to juggle 2 single-layer discs.

DVD Advantages

• Cheap. The drives are only $50, and the media is also cheap. If you want to use rewritable RW discs instead of write-once R discs, they can be had for no more than a few dollars per disc. Dual-layer discs are more expensive, but the price is expected to keep dropping.


• Fairly fast. 16x DVD writes at more than 20 MB/s. That will burn 4.5 GB in 4-5 minutes.


• Random Access. You can quickly get any data you want.


• DVD drives are becoming present everywhere. So you can read your backup on more than just your computer, and your DVD writer can be used for many more things than just backup. Not only can you use it to move large amounts of data from one computer to another, but you can burn home movies and audio to DVD and play it in other computers and set-top DVD boxes.
  

DVD Disadvantages

• Application support could be a problem. While CD writing is supported by just about any major piece of software, DVD writing is still new enough that support isn’t widespread.


• Fairly small storage space. When considering backing up 300 GB hard drives for $150, it takes a lot of 4.5 GB DVDs to make that happen. So that means a lot of disc shuffling. However, if you don’t have much data (and many individuals do not), then that’s not a problem.


• Write-only media means that you have to keep buying discs, and rewritable media has to be erased before it can be written to again. That’s just one more step that has to be done for every disc of every backup.

DVD tends to work best for an archive backup (say, of your 100 GB of movies and mp3s) that remains basically the same for long periods of time. and for data that will fit on one or two discs. If you have many GBs of new content being created and changed that you need to continuously back up, then you’ll be spending a lot of time on shuffling discs.

USB Flash Memory Key

I’m including this because it is a very popular removable storage medium that is extremely flexible and easy to use, and it has effectively killed the floppy drive.

Memory key advantages

• Tiny size. No storage medium is physically smaller than the USB key.


• Easy to use. It just doesn’t get easier than connecting to a USB port and copying over files in Windows Explorer. And if you want, you can still use pretty much any 3rd party backup software.


• Works everywhere. Every computer made in the past 6+ years has at least one USB port built-in (however, older Operating Systems often require drivers).
  

Memory key disadvantages

• Extremely Expensive $$ to GB ratio


• Small storage space. You can get 2 GB memory keys for about $100. The largest current USB flash is 8 GB, which costs several hundred dollars.


• Questionable durability. Flash hasn’t yet proven itself to be a long-term archival medium, and USB keys absorb a great deal of punishment when carried everywhere.
  The price and size are the limiting factor with the USB key for backup. They are just too pricey to use for anything but your most important and most mobile data. However, if you have very little data (less than 1-2 GB) and want the easiest possible backup, the USB key is the winner.

Hard Drive

This is a backup approach that has just recently started appearing due to the fact that hard drives have grown much larger than any other form of storage. When CD writers arrived, hard drives were about 3 GB so the entirety of one drive would fit on 5 CDs. Now that hard drives are 200-500 GB, it takes far more removable media to back it up, which is quite a headache.

So the thinking goes, “Why bother with the hassle of 20 tapes for one backup when I can just buy a second cheap hard drive and copy everything over occasionally?” It is indeed a realistic option.

Hard drive advantages

• Inexpensive. $100 will buy you 200-300 GB of storage


• Very Fast. Hard drives have transfer rates from 30-60 MB/s


• Easy to backup. While the setup is a little harder, it’s as easy to use as a USB memory key. Either just copy the files over using Explorer or use a 3rd party backup program


• Largest amount of storage. There are no worries about splitting data between multiple drives. Just buy a drive the same size as the one you are backing up.
  

Hard drive disadvantages

• Removability is a problem. If the backup hard drive is in the same computer/building, then damage that comes from outside could damage both the main hard drive and backup hard drive, rendering the backup useless. There is the additional risk that the backed up data on the backup hard drive could be damaged accidentally by the computer user. This problem is solvable, but it will require more hardware.


• Similarly, restoration of backed up data can be more difficult due to physical connection issues.


• Durability. Hard drives are the most fragile devices that we are considering. While they don’t typically break when dropped, their limit is typically lower than others. Longevity is also a concern, especially if the drive is always on. Hard drives are powered by an electric motor, and motors will eventually fail. Also, since hard drives haven’t historically been used for data archival, it is somewhat unknown how trustworthy the data will be over the span of years.