s3 sync --size-only

[ghost]

For the s3 sync command, if syncing from multiple sources to the same bucket, an option similar to --size-only in rsync to ignore time stamps and compare files only based on size would be extremely useful, as it would avoid having to put the same file just because of local time stamp differences.

[ghost]

To clarify my use case, I have multiple EC2 instances that generate files that need to be backed up on an s3 bucket. Often, the files generated by one instance are more or less the same as another's. Since the filename is the sha1 of the file contents, if the filename matches, the contents match too. Therefore, syncing up from an instance to the bucket, if a file with the same name already exists, there's no need to replace it and can be skipped. This can be easily achieved in rsync using the --size-only option, but this doesn't appear to be supported in s3 sync.

[rodriguezsergio]

👍

[jamesls]

This has been implemented in #719