A: Absolutely. The backup software's host architecture is 64-bit, but it backs up guest operating systems of any architecture (32-bit Linux, Windows 95, etc.) perfectly.
Most enterprise solutions deploy a virtual backup appliance (e.g., Veeam Proxy, CommVault MediaAgent, or Nakivo Worker). These must run a 64-bit OS and 64-bit binaries to leverage hardware acceleration. virtual backup 64 bit
Place backups on ReFS (Windows) or ZFS (Linux) to support block cloning, fast dedupe, and large file support. Avoid FAT32 or old NTFS with 4K cluster sizes. A: Absolutely