Windows 10: can I safely assign a drive letter to an EFI partition to run a chkdsk on that partition on...

I have a backup image creation program that gets an error when I try to create an image:Cluster Run Error: Cluster Run Short - Error - 21, and it want me to run a chkdsk /r. I did and it didn't help. I contacted the software company, and they said I have a FAT32 partition EFI System Partition that is causing the error.The solution is what I am questioning. Is this safe to do this?

:)

 

Drive letter for EFI system partition?

In Macrium Reflect (free), a Dell Optiplex 3046 running 6.3.1835 on Win 10 64 Pro, returns a

when performing a backup that includes the EFI system partition. Macrium's suggested solution is to assign a drive letter to that partition. The EFI partition is required for a disk image.

Before I assign a drive letter I'd like to understand what risks there are in the assignment.

 

How do I run CHKDSK on EFI System Partition?

On Windows, I used DISKPART to assign the EFI System partition a letter. Fired up DISKPART, and typed LIST DISK to find the disk, followed by SELECT DISK <N> (where is the drive number). Followed the same steps to find the proper partition (i.e. LIST PARTITION followed by SELECT PARTITION <N>), and then simply typed ASSIGN LETTER = X to have Windows mount the partition to letter X.

Then opened CMD with administrative access. Ran CHKDSK X: /f /r

Then, I tried installing Ubuntu once again, and it installed successfully!

 

Drive letter for EFI system partition?

Well, you need to know which partition/drive the error occurred on to correct the error. I imagine chkdsk without a drive letter specification just runs on the system drive (c: in your case), it runs on a specified volume/partition not across an entire physical disk.

I know that there is a thread at the Macrium support forum discussing the case where a cluster error occurred processing the EFI system partition (ESP) - was that perhaps your reference to "Macrium's suggested solution"?

If nothing wrong with your ESP, chkdsk on that with a drive letter assigned would come up good and you would still be looking for the error.

So, perhaps you need to run "chkdsk d: /r" (substitute the target drive letter for d: ) on each partition to find out which is bad - i.e., if the Macrium error message during the backup dialogue doesn't indicate which partition it is.