Backup Options

What is a backup?

A backup is a copy of data from a computer.  In a typical small office situation, a backup is a copy of all of an organisation's day-to-day information.  

A backup is a fail-safe.  It is a 'normally redundant' copy of an organisation's data, which only becomes useful in the event of data loss from a PC or server. Backing up is advantageous on a grand scale, in the event of a 'disaster' such as a server failing or a building fire, and also on a less critical scale, in the event of, let's say, a file being deleted or overwritten by mistake, where there's no other copy on the PC or server. Backups can range in size from a few files, to a complete hard drive, or even to an organisation's entire data.

Why backup?

You should backup to protect your data from the following threats:

• Virus infection
• Sabotage
• Human error
• Hardware failure
• Theft

Backups provide peace of mind and a safety net for your organisation. Think of everything that you have stored on your computer - all of the business processes that depend upon it. In the event of a disaster, such as a building fire, you would possibly lose your server. Without an external backup mechanism, such as a tape, you would lose all your important information. Think how difficult would it be to recover from the loss of the following:

• Files
• Contacts
• Emails
• Records
• Reports

However unlikely a fire may be, hardware failure is an ever present danger. Hard drives, which actually store the data, are fragile articles and whilst generally reliable, can fail, with potentially disastrous results. A quick scan over different data recovery and backup websites reveals that, while there are many causes of data loss, the single most common cause is hard disk failure.

 Backup Hardware

Hard Drive

A simple and transparent solution to safeguard against data loss is to use a technique called "mirroring".  This is when a computer has two hard drives of the same capacity and one is an exact copy, or mirror, of the other.  If one fails, the machine can continue to operate using the other drive.  This is also known as a "RAID" arrangement.  RAID stands for Redundant Array of Inexpensive Disks.  Mirrored drives are not a valid stand-alone backup system, but are an excellent way of maintaining business continuity in the event of a failure.

Advantages

• Once set up, the system works constantly and allows for speedy recovery.

Disadvantages

• While it provides a good layer of protection, it is not a complete backup solution, as RAID cannot protect against fire.  The best solution is to always keep a copy of your data off site.

External Hard Drive

External hard drives are portable storage devices, often of large capacity, which plug into a computer. You can backup an entire computer onto an external hard drive, and with modern-day USB2 connectivity technology, you are guaranteed fast access to data stored on them.

Advantages

• Large capacity
• Portable
• Plug and play

Disadvantages

• As vulnerable as any internal hard drive (suffers similar failure rates)
• Big and bulky for transport off-site/storage.

USB Drive

USB drives (also known as 'flash drives' or 'memory sticks') are very popular for file storage and can also be used for backups. Capacity may be limited, but is still adequate for some uses: a whole hard drive may not fit on one, but an organisation's most critical files may.
 

Advantages

• Fast data access with USB2
• Cheap
• Small and portable
• Easy to use

Disadvantages

• Limited capacity
• Easily lost or stolen
• Flash memory has a limited lifespan - it is not permanent

Digital Tape

This is without doubt the industry standard solution.  A tape drive is installed in the network Server and, every night, any or all of the organisation's data is copied to digital tape. Tapes have large capacity, are cheap, and easy to store.

Advantages

• Large capacity
• Inexpensive medium

Disadvantages

• Tape drives are expensive

CD & DVD

CDs and DVDs are an inexpensive but limited method of backing up.  Whilst it is possible to copy all files to CD or DVD (with DVDs having a much larger storage capacity), it is a time-consuming and labour-intensive process, often requiring multiple disks.  CDs and DVDs are a solution for backup of, say, particular project files, but not ideal for daily backup routines.
 

Advantages

• Most modern PCs come with CD/DVD writers
• Disks are cheap

Disadvantages

• Writing to DVD is slow

Off-site storage

An alternative to in-house backup systems/routines is to use a 'remote backup provider'.  Once set up, every night the organisation's updated data is copied over the internet to a secure location for safe storage.  

Advantages

• Data is secure and off-site

Disadvantages

• Requires an internet connection of sufficient bandwidth to handle the volume of data to be backed up

Typical Backup Plan

Backup plans are designed to further secure an organisation's information by minimising the chance of a bad backup occurring. You sometimes hear of organisations diligently performing regular backups, only to discover in a moment of crisis that the backup medium was corrupt and that their backups had failed.
A backup plan in which you regularly rotate your backups, ensures that if a tape is defective, there will be an additional recent backup to rely on.

A sample backup plan is as follows:

Using 10 tapes:

• Every Tuesday to Friday inclusive, use tapes 1-4 for backing up at the end of each day
• Every Monday use tapes 5-8 for backing up the previous week's data (weeks 2-5)
• On the first Monday of each month, use tapes 9 & 10 backup the previous month and quarter respectively 

For obvious reasons, remember to remove some backups off-site. Referring to the above example, tapes 5-8 and 9 & 10 should be kept off-site once used, and only returned to site for use.

You should also regularly test that your backups actually work; for example, try attempting to restore a file from a backup once a month.

Remember: a backup system is insurance, and like any insurance, you never need it until you really need it!