Last week, I took a look at the merits and pitfalls of

various backup media. The main area of concern was that some people may be

using unstable media like CD-R and DVD to back up important data—these media

can be a tempting resource for backups smaller than 10 GB due to their low cost

and fast access. However, the instability of the media (susceptibility to

‘rot’) makes the chance of recovery at a later date uncertain. The traditional

media for long-term backup and archiving is, of course, the magnetic tape—with

a native capacity of up to 400 GB and a shelf life of up to 30 years, there

really is no more reliable safety net.

In recent years, there has been another backup and disaster

recovery solution which is becoming more popular. Online backup involves data

being sent to a remote site via the Internet. So how exactly does online backup

work? DPS,

a leading online backup service provider do a very good job of describing the


  • An

    agent is downloaded from the DPS website and Installed on the computer(s)

    to be backed up.

  • The

    Central Control is installed on a Windows workstation to administer the

    agents on local and remote computers. Using the Central Control, the

    administrator selects what data to back up; frequency of backups; time of

    backups; and how long the backup is retained in our vaults.

  • At

    the time selected, the agent compresses and encrypts the data, then

    transfers it to the DPS primary data centre. The data is then backed up to

    a secondary remote data centre.

  • If a

    restore is needed, client uses the Central Control to select the data to

    be restored and the backup to restore from and the restore process begins

    immediately. The encrypted data is transmitted back to the computer where

    the agent decrypts and decompresses the data.

That’s all very well for restoring accidentally deleted

files, but what happens in a disaster if your building burns down? Most online

vaulting companies will offer emergency restores in the form of DVD media or a

mobile vault for large amounts of data.

The major advantage to online vaulting as opposed to the

traditional tape/offline vault seems to be that data is immediately available

for download, and small restores become much faster and cheaper because you

don’t need to recall a tape from the vault. With Internet connectivity becoming

faster and cheaper by the day, online backups of some sort will probably become

the norm for many medium to large firms. It may never replace the process of

taking physical backups because people like to feel they have a ‘real’,

physical safety net; however, it is probably going to run along side on-site

backups, allowing easy recovery of files, while the physically vaulted media is

kept for long-term archiving.

Does your company use online backup services? What issues

have you come up against? Do you continue to take hard backups along side the

on-line backup?