Practically everyone who works in the computer business has heard the phrase "perform a complete backup" before running a long complicated procedure that modifies the system. In my experience, however, I've found that most administrators are rather lax about developing and implementing an effective backup solution—you shouldn't be.
How often does a company need to back up its data? Does a company need to protect critical changes that personnel make throughout the day? Can you afford the downtime you would need to reconstruct the data? You need to carry over the care with which you handle your data to the care and diligence with which you back up your data.
Backup Considerations
Because backup strategies are specific to a particular company, you need to know the value of your data to your business’s operation. Most businesses running Microsoft BackOffice Server store their company-vital data on a central server. The key to developing a backup plan that sufficiently protects a company's data assets lies in evaluating the time and money it would cost to recover from a catastrophic data-deletion accident.
Another major point to consider when examining possible backup solutions is how often the company creates, modifies, and deletes data items. For example, an e-shop could lose a lot of money if the company loses even an hour's worth of data, whereas a mid-sized business that works only on documents might not modify its data as often and, thus, might not have the same backup needs.
Other primary concerns include a backup device’s capacity and speed. Most corporate servers have lots of storage capacity. Consider how much data you need to back up. For example, my main server contains 19GB of data, but much of that data is convenience data. About 500MB of data needs daily backing up; weekly is sufficient for the rest. Select a backup drive and method consistent with the amount of dynamic data on the disk. I’ve found the OnStream ADR50 drives to be appropriate for most environments. These drives hold 50GB of compressed data and are very reliable. (I'll get into specifics on drives and software in the next column.) Speed is also an important concern. Most backups run at night and on the weekends when the system has minimal to no user load. However, if the device is too slow, you might find backups still running in the morning when users begin work.
Data Security and Integrity
Although backing up essential data is the first step toward protecting computing assets, that effort is meaningless if you don’t also take steps to protect the integrity of those backups. You need to investigate the write-protection features of the drive, media, and software, especially if you intend the backups to be long-term archives. Make sure that you keep all backup media—blank and used—secure on the premises, and explore the possibility of keeping backup copies in a secure place off the premises. This precaution protects you from fire, theft, and other unpredictable events.
A Backup Plan
The following items are potential elements of a well-rounded backup plan that you need to consider when planning a company's data protection:
- Scheduling. Full backups and modified (i.e., differential or incremental) backups are the two primary types of backups. A full backup backs up everything on your disk. Although a full backup requires more time and media than a modified backup, you should perform a full backup at regular intervals (weekly, monthly). A modified backup doesn't require as much time or space, but a modified backup backs up only those files that the system has created or changed since the previous full backup. IT departments typically perform modified backups daily.
- Labeling. Although labeling might seem to be an elementary and self-explanatory topic, IT departments often overlook clear labeling of backup media. In the days of unmarked floppy disks, users might remember what was on a disk by its envelope color. Unfortunately, remembering isn’t so easy today, especially when tapes are part of your operation. Be sure that you label each piece of media.
You can use the following basic backup plan to start, and adjust it to your company's specific needs:
- Initially, back up the hard disk using the full backup method. Copy the full backup tape or disk, label both pieces of media, and store them in secure locations onsite and offsite.
- Schedule modified backups every workday evening. Label the modified backup and store it in a safe location. Use two specific tapes or disks for the modified backups, and alternate media every other day.
- Every weekend, perform a full backup using a tape or disk different from the one you used for the initial full backup. Switch between these two tapes or disks on alternate weeks.
- Each quarter, retire your backup tapes or disks and begin the next quarter with a fresh set of media.
Only the Beginning
This plan is only the beginning of an effective data protection plan. However, this plan is a good start to ensuring minimal downtime if unforeseen data loss occurs.