|< Day Day Up >|| |
Backing up the data on your network is a chore that everyone knows is important but which all too many ignore or don’t take seriously. Microsoft Windows Small Business Server 2003 includes a dedicated backup utility that makes the task simple and straightforward. Although businesses at the upper end of the range covered by Windows Small Business Server might find they need a more full-featured backup program with all the bells and whistles, most businesses will find the included Backup Utility quite adequate, especially given the integration into the Server Management console.
You’ll need to understand a number of different terms when dealing with backups. Here’s a short list of the most important ones:
Backup device The hardware device on which backups are saved.
Backup media The actual tape, disk, or DVD on which the backup is stored.
Full backup What it says—this backup includes all files in a given selection set.
Incremental backup All the files in a given selection set that have changed since the last full or incremental backup. To restore, you need the last full backup and all the incremental backups since then.
Differential backup All the files in a given selection set that have changed since the last full backup. To restore, you need the last full backup and the latest differential backup.
Windows Small Business Server supports writing to either a tape device or a hard drive. The hard-drive backup option includes both fixed and removable hard drives. There is no support, however, for using a CD or DVD writer as a backup device. In theory, you could use a CD or DVD device by using third-party software that makes them appear to be just another hard drive, albeit a removable one.
Windows Small Business Server 2003 does not directly support using writeable CD or DVD drives as backup devices. Using these drives as backup devices requires third-party software that is designed for consumer use to make the CD or DVD drive appear as a hard drive, allowing the Backup Utility to use it. Using consumer-grade software for your backup strategy is not tested on Windows Small Business Server 2003 and is not a supported scenario. You should carefully assess the risks to your business and make an informed decision before using a solution based on CDs or DVDs.
The preferred backup device has always been tape of one variety or another. Tape drives are not cheap; and large, fast tape drives are very definitely not cheap. But tape is a proven technology that has many advantages, including portability, easy off site storage, and a predictable life span. It does, however, have some very real disadvantages—probably the most important is that it is slower than the alternatives. This can create a problem with the length of time a backup takes, as well as the time to recover a specific file or files.
The alternatives to tape have their own problems, however. Extra hard drives, even removable ones, are not ideal for off site storage, and if you use any sort of rotation, they aren’t exactly cheap, either. CDs simply don’t hold enough any more. And even writeable DVDs really don’t hold enough for most backups without having to span multiple DVDs, and, most importantly, they are not a supported solution.
Although CDs and DVDs seem like the sort of backup media that should last forever, recent studies show that their actual data-integrity life is really quite short. They should not be used for long-term archival storage. They have sufficient life for ordinary backups that will be rotated and replaced on a regular schedule, but they are best not depended on for longer than a year.
Whatever backup device you choose, you will need to have sufficient media for it to manage a full schedule of backups. Don’t stint here. If the price for a batch of DDS4 or DLT tapes seems too good to be true, it probably is.
Once you’ve decided on your backup strategy, you’ll have a good idea of the number of media you’ll need to support it, whether tapes or disks. Keep in mind that media does fail, and there will be times you want or need to do something special, so order accordingly. If your backup strategy calls for 25 tapes used in rotation, you’ll probably want 30 or 35, plus a couple of cleaning tapes. Backup strategies are covered in the next section, “Designing a Backup Strategy.”
Before you spend your money on a batch of tapes, buy one of the brand you are considering and test it. And test it some more. Some brands of tapes do have problems with some tape drives. You want to make sure there aren’t any incompatibilities before you spend your money on a bunch of tapes.
|< Day Day Up >|| |