Backup vs archive: what’s the difference?

A backup is a copy of your files and programs, made so that you can recover them if something goes wrong. An archive is long-term storage for information you no longer work on but still have to keep. The two are easy to confuse because both are “old copies of things”, and a business that treats one as the other usually finds out when it needs a record it cannot retrieve.

What a backup is for

A backup exists to put a system back the way it was at a particular date and time. It answers one question: the server died, or the files were encrypted, or someone deleted the wrong folder, so how do we get back to yesterday?

Because that is its job, a backup copies everything as it stood, and it is only kept for as long as it is useful for recovery. Older copies are replaced by newer ones.

What an archive is for

An archive holds records that are finished but still have to be kept: old invoices, closed client files, the mailbox of someone who has left. Its job is to keep each record unchanged and findable for years.

For an Australian business the plainest example is tax. The Australian Taxation Office says most business records must be kept for five years, stored so they cannot be changed or damaged, and produced if it asks for them. Other laws and contracts set their own periods, and your accountant or lawyer can tell you which apply.

Why old backups make a poor archive

State records offices in New South Wales and Queensland have both written about this for government agencies. Their reasons apply to any organisation:

• Nothing is easy to find. A backup stores everything as one collection. To get one document you may have to work out where it was kept at the time and restore a large amount of data around it.
• It depends on old equipment. Reading a backup takes the software that made it, a device that can read the media and a system like the one it came from. State Records NSW says that within three to five years these become expensive or difficult to get.
• You cannot manage what is kept. A record that should be destroyed after a set period cannot be picked out of a backup, and one that must be kept can vanish when the backup is replaced.
• Media wears out. Backup tapes and drives deteriorate if nobody is looking after them.

Why an archive is not a backup either

Moving old files to an archive frees up space, but if the archive is now the only place those files exist, losing it loses them. An archive also holds only what was put in it. It cannot rebuild the accounting system as it stood last night.

State Records NSW puts it simply: an organisation needs both a way to manage its information over the long term and a backup process.

Working out what you need

1. List the records you are required to keep, and for how long. Tax, payroll and client records are the usual starting point.
2. Decide where each kind is kept once it is no longer in daily use, and check that one record can be found there without restoring everything.
3. Set how long backups are kept based on recovery alone: how far back you might need to go to undo a problem.
4. Make sure the archive is included in the backup.

Where to go next

For the backup side, start with The 3-2-1 backup rule and A backup checklist for a small business. Setting up where records are kept and for how long is part of our data management service.