This article applies to iSCSI LUNs connected to from Windows iSCSI initiator and formatted as NTFS format.

If there has been some corruption of the filesystem on the LUN, it could show as RAW format in the Windows Disk Management Tool. The data will be inaccessible in this situation.

The procedure to fix it is below.

1. Open Windows Command Prompt (make sure to run as Administrator)
   
   
2. Run the command below to check and fix the LUN for errors:
   CHKDSK X: /f
   
   
3. If and only if step 2 fails, you may need to use the below command. It will force Windows to recognise it as NTFS format:
   CONVERT X: /fs:ntfs
   
   
4. The LUN should be back to NTFS and usable from within Windows

Note: There is always a possibility that the data has already have been corrupted beyond repair. These commands are only provided as advice and are performed at your own risk. Always keep regular backups of vital data.