Backups

Although it is generally agreed that data backup is important there are a surprising number of companies who have either no backup strategy or an ineffective one. This document will outline the benefits of a good backup strategy with examples and some indicative costs. Throughout this document the term ‘backup’ is used to describe the action of making a copy of data stored on one media onto another, physically different media.

This should not be regarded as a comprehensive volume on backup strategy but as a guideline to best practice. We would be pleased to meet with you to discuss your specific backup requirements in more detail.

Why backup?

The most obvious reason to backup is to ensure that you have access to your data in the event of a problem with your computer systems that prevents you from accessing the data that is stored on them. Consider the potential impact to your business if you have no client records, no financial data, no knowledge of work in progress and so on. Although this may not be the only reason to backup it is a powerful argument to ensure you not only have a backup strategy but also that you use it!

When to backup

Backup frequency is a matter for company policy although as a guideline consider that at best it will take twice as long to recreate data (After all, you still have the current workload to deal with) so a weeks worth of work will take at least two weeks to recreate. In reality, if you are working efficiently to begin with then the recovery time will be far greater and almost certainly involve additional costs in the form of overtime and/or temporary staff.

You should consider backing up all changed data files on a daily basis. With an automated system this will only involve ensuring the correct media is available.

How to backup

A good backup strategy can only be decided upon once all of the factors involving your IT systems have been considered. How many sites do you have? Are they linked using a WAN? Will backup be done centrally or at each location? How many systems do you have? Is there a central server available? How critical is the data to the business? What backup software and devices are available? Who will be responsible for ensuring the backups are done? This is an area that we  have considerable experience in and we would be pleased to meet with you to formulate a backup strategy and DR (Disaster Recovery) plan.

The golden rule is to make sure you have copies of data that are stored offsite (Or at least in a fire safe) but are available on demand at short notice. A popular backup strategy is the GFS (Grandfather, Father & Son) rotational strategy. This uses daily, weekly and monthly media and ensures you can recover data quickly and efficiently. The choice of backup device and media is often dictated by cost and will impact the efficiency of the backups – ideally you should be able to fit the data onto a single media to enable unattended backups to take place. If you only have a very small amount of data to backup then floppy disc may be a possibility, if you have gigabytes of data then a DAT or DLT would be preferable with CD-RW and DVD/R sitting in the middle ground. No matter how much data needs to be backed up there is a device/media combination available.

Who should backup?

This is a matter of company policy, as a guideline if users store work on their local PC’s then they will often be responsible for backup. If there is a central server then a designated person will usually be responsible for ensuring the backups are done to the agreed schedule.

What should be backed up?

Although it may be tempting to do a complete backup of the entire contents of your hard drive(s) this is not always the best method unless your backup device and software support disaster recovery. If this is not an option then you will almost certainly have to reinstall at least some of the operating system before you can restore any backups you have there is little point in backing it up. Also, applications that you use will take large amounts of space and do not change often so providing you have access to the installation media there is not usually a requirement to backup applications. That leaves the data that you create, this is the most critical part of your systems to backup and where the focus should be.

For larger or critical systems a disaster recovery backup should be taken. This will be a complete backup of the entire system including the operating system, all applications, all system state data and all user data. This should be a part of the IT disaster recovery plan.

Where to backup

This will depend on many of the same factors as the ‘How to backup’ section above. Some guidelines are shown here:

Single PC, not connected to a network:

Backup to floppy disc as a minimum (Not recommended), ideally to CD-RW, DVD/R or tape.

Single PC, connected to network but data stored locally (No server):

Backup to another PC on the network, also use CD-RW, DVD/R or tape as above.

Networked PC, data stored on central server:

Backup critical data from the server to local PC (For speed), also ensure server is backed up using a tapestreamer (For offsite storage)

No matter which backup device you choose to use, you should always ensure that a copy of the data is stored offsite, after all it may not be a single PC or server crashing – it may be a problem with fire or flood causing all IT equipment to be unusable. In the event of such a disaster hardware can be replaced quickly or alternate plans (Work from home) can be actioned. As discussed above, data is much more difficult and may prove to be impossible to recover without a backup.

Cost of backup

We have provided a table below which shows the common backup devices together with media cost and capacity. All prices shown were taken from www.insight.com in July 2003 and are for guidance only. You should not regard any prices shown here as final; instead use them as a comparative guideline. It will be possible to find cheaper prices than those shown here.

Not included within the table are the speed of the backup device (Tapes are faster than discs) or any multichanger tape devices. Also excluded are ‘write once’ media such as CD/R although they are suitable for the ‘Grandfather’ (Monthly) backup as this will not be re-used. The capacities shown for the tapestreamers assume a compression ration of 2:1 which may not be achievable in reality as it is dependent on the data that you have.

The real question is not the cost of backing up your data but the cost of NOT backing up your data – that could prove to be beyond monetary costs!