In my lab, I had a broken USB drive. I was unable to write any data to the drive anymore but still was able to read data. Being lazy I did not want to reinstall it so I tried cloning.
There are multiple guides on this but most of them show comments of not bootable sticks any more or that the partition layout is in the wrong order.
How to clone it successfully
To do this I used the application USB Image tool on windows. This is really easy.
Plugin your source drive and start USB Image Tool.
Select device mode, select the drive, and click on backup.
Now click on backup and give the file a name.
Wait until the dump is done. Now plug in the destination USB drive. This has to have an equal size or bigger. In this guide, I will dump the backup to a 16GB drive.
Plugin the new drive after the backup is complete.As you can see this drive is a 16GB drive.
Before dumping back the backup be sure to enable the option: Fix GPT after Restore. This is crucial to prevent partition failures or non-bootable drives.
Now press the restore button and point to the backup file.
Accept the restore message and wait out the process.
As you can see the partitions are ok and have 7.64GB left of unused space.
After this, you successfully backup up your USB ESXi drive and restored it to a bigger drive. Also, it’s still booting and your host is none the wiser!