garethgeorge
Add support for --read-data-subset=nS
Currently, --read-data-subset=x% is supported by Backrest, but supporting -read-data-subset=nS would be a great addition so that a subset of a specific size can be checked.
For my use case (and I'm sure many others), I use restic to backup to a remote site. My current restic backup is 2.25TB of data, and that can grow as time goes on. When running restic directly I was using --read-data-subset=10G so that a random subset of only that size is checked every time, and I don't have to worry about my restic backup growing or shrinking in size.
Related closed issue: https://github.com/garethgeorge/backrest/issues/75
This is useful when you get a certain amount of free egress data from the storage provider, or want to enforce a monetary ($) limit on the cost of a check operation.
