DATA BACKUP

Are you prepared for a disaster?

How would you cope if your office or work premises were destroyed by fire? You may well be insured but insurance companies will expect you to have copies of important data. You would need access to you customer's information, what orders were you processing? Shouldn't you call them and let them know the circumstances before they go elsewhere? Do you have their contact details? What about debtors? If you loose your accounts information, you wouldn't know who you owed what and this could disrupt your supply chain. How would you chase who owes money? Without it you wouldn't be able to pay staff etc. What about VAT returns and other statutory information? These are but a few of the problems you could face - could you survive?

Remember too that a backup is no good if it's incomplete, out of date or stored in a disk box on top of the Computer that just got consumed by fire! Have you ever checked that you can restore it? We can offer a variety of backup solutions and advice at cost effective prices.

We can supply and install:-

Stand-alone PC Backup

Individual PCs are probably the easiest but least backed-up of all.

The range of options now available mean that there really is no excuse for not taking copies of critical data. The days of tedious backups spanning multiple floppies and taking 30 minutes are history for most of us! Most PCs have USB and a flash memory disk is ideal for frequent and rapid backups that can be carried in your pocket! Generally, no software is required and the units are rugged and not susceptible to shock etc - they retail for as little as £10 and you can currently get around a Gigabyte for under £100! For larger backups a USB hard disk is a useful method to protect against disk failure etc but may not hep in the event of a virus infection if it is left plugged in! likewise, they are a bit bulky to carry around and therefore aren't much help if there was a fire and the unit is still connected to the host PC! For more occasional and off-site backups, ZIP disks (IOMega) or recordable CDs/DVDs are a more suitable choice.

Server Backup

Peer-to-peer or dedicated servers require more substansive backup.

Server backups usually need to protect more users and as the backup is central, more frequent and formal systems are usually utilised. Tape remains the primary route for server backups but occasionally we encounter other methods such as MO drives (a combination of magnetic and optical storage technologies). Chosing the right tape format is important however as there are a range available and cost is always a factor. Newer, higher density drives are generally significantly more expensive but older technogies fall rapidly in price once superceeded. A smaller capacity tape may suffice but you will need to consider that most backups are scheduled to run when most files aren't in use - i.e. at night and without expensive tape changers or a member of staff sitting waiting to insert the next tape at 3am, you're going to have a problem if the backup exceeds the tape size! There are ways around this however and by managing the backup, you may find that there are items on servers that can be excluded from the backups. Centralised installation folders, patches, service packs etc don't need backing up daily providing there is a manual method to back them up when changes are made. It is also possible to run incremental or differential backups but these do make the task of restoring data much more complex and create the need for disciplined tape use! When selecting tape formats, it is also worth condidering the cost of tapes as ultimately you will probably spend more on these than on the drive itself and prices vary significantly - DDS or DAT tapes are generally much cheaper than rival formats like DLT or Travan. Many network administrators also have a PC with plenty of excess storage where interim backups can be scheduled for files that are particularly important or frequently changed. Sometimes even a backup server to replicate domain functions and data is implemented - ideally in another location or linked site.

Backup Routine

An example of a simple 12 tape backup cycle giving up to 6 months archive.

The sequence assumes a backup is taken 5 working days, run overnight and the tape swapped the following day.
Label 12 tapes: MON, TUE, WED, THU, FR1, FR2, FR3, M1, M2, M3, M4, M5
Using each tape, the following usage sequence is followed:

MON, TUE, WED, THU, FR1, MON, TUE, WED, THU, FR2, MON, TUE, WED, THU, FR3, MON, TUE, WED, THU, M1
MON, TUE, WED, THU, FR1, MON, TUE, WED, THU, FR2, MON, TUE, WED, THU, FR3, MON, TUE, WED, THU, M2
MON, TUE, WED, THU, FR1, MON, TUE, WED, THU, FR2, MON, TUE, WED, THU, FR3, MON, TUE, WED, THU, M3
MON, TUE, WED, THU, FR1, MON, TUE, WED, THU, FR2, MON, TUE, WED, THU, FR3, MON, TUE, WED, THU, M4
MON, TUE, WED, THU, FR1, MON, TUE, WED, THU, FR2, MON, TUE, WED, THU, FR3, MON, TUE, WED, THU, M5

Remember that tapes don't last forever and are designed to be 100% typically for up to 300 uses this would be around 3 years for the MON, TUE, WED, THU tapes and longer for the others. We tend to recommend 18M to 2 years for these only to ensure safe margins but it is definitaely worth check with your drive and/or tape suppliers as figures vary by type and manufacturer.

When archiving tapes for long periods we also recommend retensioning tapes every 12-18 months but probably more important is to keep the temperature and humidity constant as variations can seriously affect the reliability. This is particularly relevant when tapes are taken off site and storing them in a cold, damp garage isn't particularly a good idea ;-)

Tape heads need regular cleaning to ensure error free operation and/or damage to tapes - every 20-30 hours of operation is fairly typical and given that a drive probably runs for 2-3 hours per night, once every couple of weeks is a good guide for some drives - cleaning and data tapes are less abrasive thatn they once were and risk of damage from over-cleaning minimal and less likely than damage through under-cleaning! Better quality tapes will reduce the cleaning requirement and it isn't always a good idea to wait for the cleaning request indicator (where fitted) to show. If you keep records of backup and cleaning operations however, you can quickly establish optimal cleaning frequency by waiting occasionally for the indicator to show - if it shows after 100 backups then cleaning every 90 would be a good bet. Whilst replacement tape heads aren't cheap, lost data could cost more!

An example backup log for 1 month is available here (84K) and has columns for tracking cleaning and free space for up to 3 disks/RAID containers.