I need to compare two directories on Linux filesystems on two separate servers in order to identify whether all the files from SERVER1 are present on SERVER2. The total data set is about 4TB of files in all.
The data has been copied across using rsync but I cannot take the chance that anything is missing as the source data is going to be purged once the migration is complete.
I have tried a number of approaches to compare the data (diff of the recursive directory listing, rsync in dry-run mode) but can't find anything that gives me a manageable output or doesn't take forever to run.
Interested to hear different approaches as so far I don't have one I'm happy with.