As president and founder of Integrated Technology Systems, Stephen focuses on small and medium business solutions. Stephen earned a Computer Science degree from New York University and lectures extensively on computer technology subjects.
Backups are more than tape copies of your hard drive; they are a regular procedure, and a company must have an effective backup policy to ensure protection against data loss. The old adage that your data is only as good as your last backup is certainly true to a point. You could back up onto the same tape every night and have a copy of your hard-drive contents. However, not all data losses are the result of a catastrophe. If someone accidentally deletes a file and doesn’t notice it for several days or weeks, there will be no copy of the file on your backup tape because the tape contains only the image of your server’s files from the preceding day.
Rotation, rotation, rotation
Implementing a policy of rotating backups is the key to safeguarding data in the long term. A rotation of five tapes gives you one week’s worth of data while nine tapes give you one month’s worth of data (four dailies from Monday through Thursday and one for each Friday of the month). Twenty-one tapes give you one full year’s worth of backups and is generally considered the safest. This includes four dailies and five weeklies plus 12 monthlies. Any file that is deleted or corrupted in the last year could be recovered from one of these backup tapes.
There are three factors to consider when determining which Hewlett-Packard backup is the best for your server: price, capacity, and window of opportunity. The last item is often overlooked. You want your backup to begin and end in a 12- to 16-hour period and occur during the period of lowest network activity, which is usually at night. (Backup software uses a great deal of server capacity, so users will find the system very slow if the backup is still running the next morning.) At 6GB per hour, you can reasonably expect to back up 80GB per night.
There are at least three widely used tape backup systems on the market. These are the three major types:
Digital Audio Tape (DAT) technology was created in 1987 but is still in use today. DAT uses a small tape in a 4mm-tape format and is probably the most widely used in file servers. At the high end, HP offers a DDS-4/DAT40 system, which can store 20GB natively and up to 40GB using compression.
Digital Linear Tape drives (DLT) are also very popular, but considerably more expensive. DLT is a relatively new technology that stores 40GB of uncompressed data and 80GB of compressed data. The advantage of using DLT technology is speed. While a DAT drive can back up six gigabytes per hour, a DLT drive can back up twice as fast.
Travan technology, originally developed by 3M and Colorado Systems (which is now a division of Hewlett-Packard), is an entirely new format. The development of this system broke the price barrier of DAT drives and has been very popular for workstations and smaller-capacity file servers. Up until very recently, this system was limited to 8GB of capacity, but a recent innovation has brought the capacity up to 10GB of storage natively and 20GB using compression. HP does not sell the Travan tape drive.
If you are on a tight budget, the Travan unit is the best choice. Many people buy servers with a much greater storage capacity than planned. If you think you will be storing 8-18GB, get a DAT unit for its price and performance. If you are going to store substantially more data on the server (and you have room to expand by adding hard drives), invest in the DLT drive. The speed alone will guarantee that the backup will finish in a just a few hours.
If your total capacity exceeds 40GB but is less 6,400GB, you should consider the hp surestore dlt autoloader 818. This system is based on an eight-slot magazine, which will supply backups that span multiple tapes with a sustained transfer rate of 12MB per second. You can easily back up 80GB overnight and get the advantage of producing multiple backups during the week without having to change tapes. To help select the right product for your needs, develop a backup strategy that considers the following:
- Degree of backup: determine what should be a part of the backup -- work files, applications, or the entire system of each employee.
- Capacity required: measure the total size of the backup to determine the overall volume to be stored.
- Timing: find out when you will set up your backup schedule. Do you have only a few hours or can it be done overnight?
Once you have your backup system in place, make sure you establish a regular backup schedule. In addition, test your backups to make sure they are successful and that the restore process works.
A catastrophic disaster can be as small as water spilled on a computer. Don't delay.
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