"hashes could not be checked" but which? (not cryptcheck) S3 to S3


I’m using rclone to sync buckets from ceph S3 to AWS S3. And using “rclone check” to make sure they get copied OK. The check output says “52 hashes could not be checked” out of 75k files. I am not using cryptcheck

  1. why can’t they be checked?
  2. which ones can’t be checked?

I presume the checksums aren’t being returned in a header somewhere, but what am I looking for? Debug output doesn’t actually give you any extra debug info, just “somefile OK”. I was expecting more like “checking somefile, getting hash from service A, getting hash from service B” so I could actually tell which files have issues.

Don’t really want to strace the whole process, but you know…


Sean Purdy

Not all objects on S3 have MD5SUMs. If they were uploaded with multipart upload they won’t have MD5SUMs.

You can run rclone check with -v or maybe -vv to find out. Or run rclone md5sum and looks for the gaps.