WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
SolarWinds Backup - Modern server backup software
WizTree - WizTree quickly finds the files and folders using the most space on your hard drive. It scans the MFT (Master File Table) instead of crawling the entire disk which makes it very fast.
Zerto - Virtual replication & recovery solution
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.
ShadowProtect SPX - ShadowProtect backup and disaster recovery software ensures on-prem business systems and data are fully protected and always available.