When you extend a volume by using FSExtend, the volume may show as "raw" in disk management. However, when you run chkdsk, the file system is shown as NTFS.
Additionally, you see the following error message in the System log:
Log Name: System Source: Ntfs Event ID: 55 Level: Error Description: The file system structure on the disk is corrupt and unusable. Please run the chkdsk utility on the volume <driveletter>:
The issue occurs because of one of the following reasons:
The file system structure on the disk is corrupted.
There is not enough disk space for the file system extend.
To resolve this issue, use one of the following methods.
If there is too little disk space to mount the volume, shrink the NTFS transaction log to 4 MB. Then, the disk will have enough space to mount the volume.
To do this, follow these steps.
To shrink the NTFS transaction log to 4 MB, run the following command:
chkdsk d: /l:4096 /f
Determine whether you can access the disk. If you can access the disk, you should free up some free space and then return the NTFS transaction log to the default value of about 65 MB. To do this, run the following command:
chkdsk d: /l: 65536 /f
Run the following command on the disk to fix any errors on the disk:
chkdsk /f <drive>
After chkdsk is completed successfully, restart the server. Then, run FSExtend on the drive to extend the file system. To do this, run the following command:
This should extend the file system on the drive, and the disk should be accessible.