Hello,
Why only the first revision is with the -hash?
Duplicacy by default only scans the contents of those files whose timestamp or size has changed since last backup, unless the -hash option is provided, in which case the contents of all files will be scanned regardless their timestamps or sizes. The first backup has no previous backup to compare with, so the -hash option is enabled automatically.
Hello,
Why the -hash option is not avaiable for all the revision as default?
The -hash option makes the backup slow – it needs to read every bytes of a file to determine if the file has been changed.