Best practice, minimum retention periods.

[Alan Casey]

I was wondering if anyone knows if there are are standards regarding retention periods for ignite images of production systems.

This will be a new system, with ignite images taken probably weekely, and my bodd is only planning on keeping 2 images at any time. As well as just 7 days worth of application data on our backup server!

I think this is crazy but need to be able to quantify what best practice is in the area of backup retention periods. These systems are core business systmes and we perform off site Disaster recovery on them.

[OFC_EDM]

You'll never get a one off answer on this as there are many variables at play.

What will determine your retention requirements will be the business rules surrounding the data.

The data owners will be the ones to determine how long to retain the different types of data. Not the admins backing it up.

In one of my old environments Ignite images were only required weekly on the Ignite server. Older images were backed up to tape and retained for a few months.

User data fell into a few categories.
HR
Business Unit specific
Security devices (logs)
etc etc etc

We met with each units data owner. This was the tough part. To determine the data owner and formally document it and have it accepted by the companys board.

For legal reasons certain types of data were not backed up at all.

Other data had multi year retention periods.

And other data had indefinite retention as the law was unclear. The lawyers kept the pulse on the issue and the retention periods would be reviewed annually to determine if they were to be adjusted.

The point is the business needs to take ownership of setting the retention periods for data.

At an administrative level for recovering systems the backups for restoring systems should not include "data". And then the retention periods for recovery backups can be set by the IT manager.

If the business owner only requires 7 days of data. And they've been fully informed of the risks for recovery then it may be an ideal solution for that site.

Communication with all parties with an investent in the data and the speed of recovery is key.

I have a feeling this thread will grow as this is a very fluid topic.

You may want to look into ITIL practises as a guide.

[Jeeshan]

its better to figure out how often you have change anything in your system.

normally weekly, monthly or fortnightly backup is best practice.

[Alan Casey]

Thanks Kevin, I wis our Business could be more useful on this issue, but the requirement we have from them is to be able to rovocer to the previous working day in the event of a disaster.

[OFC_EDM]

Now from a purely backup perspective.

I like the following schedule:

I-Incremental/Differential (daily)
F=Full (monthly)
SF=Simulated/Synthetic Full (weekly)

Monthly
Week 1 (staring with Monday)
I I I I I F - I
Week 2,3 and 4 (staring with Monday)
I I I I I SF - I

This gets a full of each system each week with an incremental or differential daily. Depending on the load of the system and the type of data.

The Synthetic Full was used to get a "Full" backup of the systems without impacting intensive processing on the systems on the weekend.

Where possible instead of SF's we took snaps of data, mounted elsewhere, and did a normal Full backup.

For some systems Simulated Fulls were completely removed once Virtual Tape libraries were implemented.

Dailys were kept for 6 weeks.
Monthly Fulls were kept for 1 year.
Annual Fulls were kept for 7 years.
Ad Hoc backups were retained for as long as the business owner specified.
Ignites were run weekly with the 2 most recent images stored online (On Ignite server)

[OFC_EDM]

You mention your requirement is to be able to recover from the previous business day.

You need to also get agreement on how quickly the system(s) have to be back up and running from an OS perspective.

And define how quickly to recover from a data perspective. So that your application admins / DBA's know how long they have to verify the data is intact and ready for business use.

Those definitions will determine the technolgy required for the backups.

Keep data and OS requirements separate if possible. This will make definition of your responsibilities easier.

A weekly ignite is adequate for your situation. As long as you run Ad Hoc ignites after you do any system changes/patching in between the weekly Ignites.

You may want to raise the 7 day retention period as a potential legal issue. Depending on the data there may be good reason to retain the data for longer.