manually deleting old .bak files. Problem?

[dpsmith]

Due to lack of space, the other day I manually deleted a 5 day old [database].bak file that was created through a maintenance plan.
We dump it out to a folder on the C:\drive
The other 4 days I left.
I adjusted the maintenance plan to only backup 4 days from now on.

I was told that was a very bad thing to do.
That it could corrupt the database or server.

How is that possible?
What is the negative impact that could have?
Other than losing that day, what's the big deal?
It's not like I can go any further back since we don't backup more than 4 days now.

I read something about interfering in a date-in-time restore?

I've been doing this off and on over the years and never considered that it might be a bad thing.

This is a SQL2005 server.

Can anyone clarify for me?

 

[dpsmith]

Just to clarify, I right clicked and deleted the .bak file through Windows Explorer and *then* adjusted the Maintenance Plan down to 4 days.

 

[SQLBill]

Depends...it seems that you are only doing a full backup every day. If so, then there is no problem.

However, if you are doing a combination of full backup and differential backups (or even tlog backups), then you might have a problem

If you do differential backups, tlog backups, or both, then you need the full backup that they are part of or you can't restore them.

We would have to know more about how you are doing backups to give a really good answer.

-SQLBill

The following is part of my signature block and is only intended to be informational.
Posting advice: FAQ481-4875

 

[mrdenny]

<sigh>

Deleting a backup will never, ever, corrupt a database or the server. Please tell whoever told you that to stop working with technology.

The thing to worry about is what Bill has talked about where you may (depending on your backup strategy) not have a complete backup set making recovery impossible. If you do full backups daily you are fine. If you do full backups weekly and differentials daily you are hosed, and need to rethink your backup strategy. If you can post your backup strategy we'll let you know what changes (if any) you need to make.

Denny
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