Skip to main content

Is your SQL Server Database backup good enough? Can it save you during a disaster?

Met a DBA from a company who are in business for ~2 years. During the conversation came to know they have never tested their backup file - not even once. Also, they have very rarely used DBCC CheckDB command. Should I call it as surprised or shocked?

It has become common to see Database Administrators to have fancy DB Backup plan, automate it and that's it. Their idea is whenever the need arises (read as disaster strikes) they can make use of it and restore the database. Although theoretically sounds like a good plan it actually isn't. Why?

All those efforts to take regular backups would become completely useless if those files can't be used to recover the database. One important question missed by many companies to whom I have consulted for - "Do we regularly make sure that we are able to restore a database from our backups?".

Despite backup process has succeeded how do we know it isn't corrupted (or) has some issues which don't allow it to be restored properly?

Our data is only as good as our last restorable backup

The bottom line is unless we do a database restore somewhere, we can't be completely sure that a given backup file is good.

At a high level, based on the business need we should first decide on:
- How much of "downtime" the system can have,
- How much of "data loss" is acceptable,
- After that put together a "Backup plan" to satisfy those requirements.
- Then the "Restore plan" should make sure all backup files are verified to be perfect and restorable in a test environment. Believe one would be already aware & using DBCC CheckDB often if not check the link provided at the end of this article.

DBA need to have a system that allows them to periodically review their plan and ensure they can get everything back up & running again.

Take away: I can't stress enough - Test your Backup file by periodically restoring in a test environment and make sure it's fine.

Recommended for further reading:

1. Paul Randal's The Accidental DBA (Day 8 of 30): Backups: Planning a Recovery Strategy
2. Award winning Maintenance script of Ola Hallengren
3. DBCC CheckDB FAQ by Kendra Little

Comments

Popular posts from this blog

My Wedding Anniversary :)

Six years back on the same day I married Sai Lakshmi (12-July-2000). I know Sai for almost 13 years now :) I fell in love with her during my 12th standard. I know @ 17 yrs any person wouldn't be matured enough to make a big decision like this. But thank God my choice was perfect :) Even now, very often we used to think about the past and laugh at our behaviors/actions then. My love story would be really interesting (at least for me and Sai :)) and I am sure none of you guys would be interested in reading about it so lemme not get into it in-depth. But one thing which I want to share is "Without Sai, I wouldn't have entered into the IT field at all". She was instrumental in convincing me to study my Master's degree in Computer Application. That's the move that changed my career. Till my schooling, my dream was to either become a "big" sportsman (Cricket and Badminton were my favorites at that time.) or an Aeronautics engineer. Unfortunately, my l...

What should one look @ while buying a land in chennai?

Offlate people have started thinking about investing their money in lands. I too think that to be a wise decision only! As most of us know buying a land in chennai (for that matter any where in the world) isn't an easy affair. I was just wondering what all one needs to look at before deciding to purchase a land. I thought I would put down what ever I know about this subject here. [Guys pls free to correct me if I my understanding is wrong somewhere. That way, it would help me understand as well as others who might read this in future]. Here we go ... 1. One should not buy farm lands if they want to build a residential house sometime later there. Because to my knowledge its illegal to build residential houses on lands meant for irrigation. 2. Encumberance Certificate -- This is what is shortly refered as "EC". One needs to get an EC from local sub registrar office (i guess we need pay a small amount for this). From this we / our lawyers :) can find out whether the guy who ...

Tips for attracting more comments …

After a long silence I am blogging regularly for almost past 2 months now. Btw, I use “ eXtreme Tracking ” to track the traffic into my blog. When I check the summary of those results I am really happy to know that in the past 231 days I have got 6711 unique visitors . Out of which last month I have attracted 1362 unique visitors and this month (as of today 7 PM) there are 1733 unique visitors. I think this to be a good count. I want to reiterate that out of 231 days I have seriously blogged for couple of months only. Ok with that information, I want to talk about the problem in hand. Only recently I started thinking “dude, you are getting decent amount of readers on a daily basis. But then you aren’t getting much feedback from them. What’s the problem?” Just because I am not getting decent amount of feedbacks does it mean my blog isn’t informative? I really don’t know but I know that, normally people are reluctant to post their views as comments on site for various reasons. In my vie...