Data Security - Backup

Many companies are now completely reliant on the data stored on their network servers, PCs, laptops, and mobile devices. Some of this data is likely to contain either personal information and/or confidential company information.

Here we look at some of the issues to consider when reviewing the security of your computer systems and data.

Data backup is an essential security procedure and needs to be undertaken on a regular basis. There are a number of points to consider.

Systems and Applications Software Installation media

Ideally, once software has been installed, the original media should be stored securely off-site.

Data file locations

In a network environment some data files might be stored on the server and other data files stored on local drives. In which case separate backups may be required for both the server and one or more PC’s.

Ideally, a network solution should be provided which ensures that all data is re-directed to the server.

Backup strategy and frequency

There is likely to be a need for two parallel backup procedures; one to cover a complete systems backup of the server(s) and another to incrementally or differentially backup data files which have been updated since the previous backup.

The most common backup cycle is the grandfather, father, son method. With this, there is a cycle of 4 daily backups, 4/5 weekly backups and 12 monthly backups.

Media, such as tapes, can be re-used many times, but they do not have a finite life and will need replacing after 2-10 years depending on quality and number of times used.

Backup supervision

Someone will need to be given responsibility for the backup procedures. The person responsible needs to be able to:

• Regularly ensure that all data files (server and local) are incorporated in the backup cycle(s)
• adapt the backup criteria as new applications and data files are added
• modify the backup schedule as required
• interpret backup logs and react to any errors notified
• restore data and test data can be restored, from backup media
• maintain a regular log of backups and where the backup media are stored.

Applications backup routines

Many accounting and payroll packages have their own backup routines. It is a good idea to use these on a regular basis, and always just before critical update routines. These data files should be stored on the server drive.

Local PCs

Certain users will have applications data files exclusively on their local drives (such as payroll data for example) and these will require their own regular backup regime, which as mentioned in the previous paragraph may consist of a combination of backing up to media and backing up to the server.

Backup media

Selecting the right media to use depends on budget, how much data there is and the networking operating software. For small to medium networks, tape backups are still widely used – but the cost of the tapes can mount considerably over a period of time. For the new business, external hard disks provide a good backup solution.

Optical storage such as CD/DVD, or Blu-Ray may also be considered a cheaper alternative, but capacity and life (see degradation below) is limited.

Backup retention

Backups should be stored in a variety of both on-site and off-site locations. On-site backups are easily accessible when data has to be restored quickly, but are at risk from either fire or other disaster.

A large number of businesses use an on-site safe, however, this will be useless if it’s buried under tons of rubble, or, if the premises otherwise become inaccessible.

Off-site backups have the advantage that they can be recovered in an emergency, but

a) they still need to be stored securely and
b) need to be reasonably accessible.

Finally, certain type of records, such as accounting records for example, need to be kept for a minimum period of time (i.e. 6 years) and this must be borne in mind when developing the data backup strategy (also see below regarding degradation).

Backup media degradation/decomposition

Backup media degrades and the data stored on them decomposes over a period of time.

Optical media such as CD/DVD and Blu-Ray are particularly sensitive to light (photosensitive), so ensure that they are stored in a dark environment. They are also prone to damage caused by writing on them with a pen. Finally, this type of media is not designed for long-term storage - lasting possibly as little as 2 years.

Backups should be checked on a regular basis for signs of digital decomposition, and tested to check that data can be successfully restored.

In-house or cloud?

Many ISP’s and third-party IT service organisations, now offer either as standard, or as a chargeable extra, off-site data repositories. The immediate appeal is that the data is stored off-site and is quite likely to be encrypted. However, the key question to ask is will you be able to get your hands on these backups in an emergency?

We would always recommend therefore that if a third-party is used, that the business uses a combination of both traditional in-house backup solutions, and cloud backup services.

How we can help

We can provide help in the following areas:

• performing a security/information audit
• drawing up a suitable backup regime
• training staff in security principles and procedures.

Please do contact us if we can be of further help.

Stewart Associates (Shrewsbury) Ltd, Chartered Accountants, Tax Consultants & Business Advisors
Emstrey House (North), Shrewsbury Business Park, Shrewsbury, Shropshire, SY2 6LG.
Telephone: 01743 235 236 Fax: 01743 264 404 Email: ian@saltd.org