Security > Disaster Preparation & Recovery

Backing Up Your Data - update

By Marcus Otite

What is the best device to use to back up your data? Marcus Otite, Circuit Rider formerly at Superhighways Partnership, briefly outlines the options

Why it is important to back up your data

You should have backup copies of all your data for a number of reasons - a file can be accidentally (or maliciously) erased, hard drives and other hardware can fail, your PC or server could be stolen, and, in extreme cases, disasters such as fire or flood can occur. This could mean losing all your data and information, which may be critical for the running of your organisation - how long could your organisation survive if it lost all its client data?

What to use

There are several methods you can use to back up your data. These include: 

• CD/DVD-Recordable
• External hard drives
• Tape
• Online back up services

CD/DVD-Recordable

Whilst in the recent past, floppy disks and other removable media such as zip drives were adequate to back up, they have little capacity and are generally outmoded. Some organisations use memory sticks which although are cheap and convenient are a massive security risk – they are easily lost, broken (stick one inside your back pocket and sit on it…) end up in washing machines. CDs have a capacity of 700Mb and DVDs 4.7 Gb (about six CDs worth) so unless you only have a very small amount of data to back up DVD should be used. DVDs are universally available and relatively cheap. DVD-RW discs will allow rewriting but given the cost difference, they aren’t recommended. DVDs can be damaged though which could be disastrous when trying to restore lost data – we’d recommend that an external hard drive is now a better option given the low prices. 

External hard drive

These devices have become more popular as prices have fallen, and for good reason - they are mobile, fast, have large capacities, are portable and compact - all these things make them good candidates for backing up. Units are available which are tailor-made for backing up with capacities of up to 1Tb (1000Gb) and include basic backup software. However, the fact that they are so mobile increases the risk of theft so a level of encryption will enhance security should someone try to get the data off them.  

They could probably be used in conjunction with another method of backing up such as using DVDs or online as it's unlikely that you would want to regularly take the drive off the premises for disaster recovery purposes – a better alternative is to have a number of hard drives so one can be taken off-site.  

Another option is to use a NAS (Network Attached Storage) device as a primary backup device. Whilst they are bulky and would not then be removable they do have the advantage of being quick and in some cases come with multiple disc in a RAID formation so that there is built in redundancy (if one disc fails, the other will take over with no loss of data as in a server disc array). 

There are also variations on the NAS which provide almost instant backup capability – there is no backup schedule as such (most backups are run overnight so files aren’t being changed as the back up is being carried out and cause corruption) but files are backed up constantly.  

Tape

Tape is still a common backup media - with appropriate software it's easy to use, the medium is small and portable so taking off site for security and peace of mind is relatively simple, it can store large amounts of data and tape drives are usually very reliable.  

There are, bewilderingly, several different types of tape which have varying storage capacities - DLT is probably the most common for smaller organisations (up to 160Gb storage) with SDLT (up to 320Gb) and LTO (up to 1600Gb) catering for larger servers.

Note that the tape drive needs to be matched to the capacity and type of tape you want to use - when selecting a drive, it's worth overestimating the amount of data you're going to back up - it's sure to increase! Capacity is given in the format 80/160 which means that this particular tape can store up to 80Gb uncompressed or 160Gb compressed. 

You would generally only install one tape drive in a small organisation usually on the server or the main PC where you are storing information if you have a well structured peer-to-peer network. Make sure you do a test restore alt least every quarter to verify and validate the backup sets 

Online back up services

These take advantage of the popularity and availability of broadband connections to upload files to a web server. Various companies offer this service including:  

• IBackup – www.ibackup.com
• Back2go (formerly BackUpMyStuff) – www.back2go.com
• Iron Mountainhttp://www.connected.com/ – www.ironmountain.com/digital
• FlashBackup – www.flashbackup.com
• Backupdirect – www.backupdirect.net
• Ampheon - www.ampheon.co.uk
• Zen backup – www.zen.co.uk  

Your support contractor may have a favoured solution, so talk to them first before signing up. These services use incremental backups so that only the first backup would be of all the user files in the shared directories - after that it would only backup those files which were new or had been changed. Software is provided allowing you to schedule backups out of office hours and to restore.  

This type of system, although it has obvious hassle free advantages, is currently quite expensive unless you have relatively small amounts of data to backup. 

Backup software

Devices such as a tape drive or external hard drive can copy the entire contents of a hard drive automatically when you aren't around depending on the type of software you buy, for example, ArcServe, Symantec Back Up Exec and Dantz Retrospect.

Alternatively, if you have a Windows server (or PC), it comes with NT BackUp (Windows Backup and Restore Centre in Vista, Windows Server BackUp in Windows Server 2008) which can be augmented with BackUp Assist which will allow for more advanced backing up of, for example, Exchange mail stores. The software also assists you to restore the files from the tape - a backup is no use if you can't get the data back onto the machine again!

More Information

This article is based on one written by Marcus Otite, Circuit Rider  at Superhighways Partnership, which previously appeared in their newsletter. Thanks to Marcus and Kate at Superhighways for allowing us to use.

See also: Techsoup article Backing Up Your Data