Error 23 on transaction log backup, full backup works fine I have a database with the database files on the E: drive, and logs files on the D: drive.

I'm getting the following error when trying to run a transaction log backup:


  Read on "D:\LOG\AOA_Log.ldf" failed: 23(Data error (cyclic redundancy check).) 


I'm also getting a bad block message in the Windows event log.

A Full database backup works fine.

Can I change the database property to simple restore and shrink the log file?

Can I run chkdsk on the D: drive (need to dismount) without messing up the database?

The server is a VMWare guest with the data residing in a disk array.
To answer the two specific questions in your post:


  Can I change the database property to simple restore and shrink the log file?


You can switch to the simple recovery model and shrink the log.  This might workaround the problem for a little while if it moves the data off of the faulty area.  Or it might cause more problems (if there are more "bad" areas in this drive / array that get written to).


  Can I run chkdsk on the D: drive (need to dismount) without messing up the database?


Again you can do that, but there are some caveats.  Tony mentioned one in a comment:


  You will need to stop SQL Server or detach all databases that have files on D: before you dismount it.


So there will be downtime involved for this.  Tony also mentioned that, before disconnecting everything, you should take a full backup and restore it somewhere else, to make sure the backup was good.  That way, once you have finished chkdsk and resolved any issues there, you can confidently restore from that backup.