Backup Strategies
1 February 2011
Would your business be adversely affected by loss of company or client data? If so you need a backup system
Specifying a system starts with defining a backup policy (what, when, why), then a strategy (how) and finally decisions can be made on hardware & software
Backup Policy
- What you need to backup
- How often
- How long you want to retain data for
- Availability & turnaround time for data restoration
- Offsite or onsite backup
Backup Strategy
- Storage capacity
- Onsite / offsite / online
- How to manage retention
- How to manage archive material
Writing the backup policy usually throws up all kinds of questions regarding which files are needed and which are not, whose job it is to delete unneeded files or archive old ones, and how that process is managed. In this respect a backup policy can be very helpful – it forces you to look at these issues and, hopefully, address them.
A typical setup is illustrated above. Data is divided into Current Work (client jobs & live company data), Archive (old jobs) and Resources (Fonts, graphics, templates, etc). Current Work is then backed up according to your policy (usually daily, overnight) and an offsite backup created if required.
If your requirement is to keep previous versions of documents then the Current Work backup will exceed the original in size. Storage capacity is always an issue with servers & backup so recognising what data is live (Current Work) and what will remain unchanged (Archive) is vital so resources can be allocated appropriately
Archive & Resources, because they change only rarely, can be backed up according to a different schedule. If the data is on a RAID, and is Read-Only (in other words, is not available for most users to modify), you might consider it appropriate not to have an onsite backup but keep your Archive backup offsite
Backup systems are required to do quite complex tasks but must be simple to operate & understand. That’s a challenge, but it is doable if the tasks are well-defined and documented and the system is managed properly
For further reading see Michael Dhaliwal’s summary of software products, Enterprise Backup Solutions