Table of Contents
Zero-Fill Disk Drive Free Space
There may be various reasons to zero-fill the free space on a disk drive:
- Make the disk more compressible for backup
- Faster than a secure-erase
- Will force a drive to retire any bad sectors in empty space before they are reused
Do not do this on SSD drives!
This may cause a thinly provisioned virtual disk to balloon out to it's fully provisioned size! But it can also have a profound impact in the size of VM (image) backups.
Windows
https://docs.microsoft.com/en-us/sysinternals/downloads/sdelete
sdelete -z x:
sdelete can also be used for secure erase.