[SOLVED] S3cmd failed with Error Code 74 when uploading to Amazon S3

My backup to Amazon S3 started failing Tuesday morning. This is the command

Code: s3cmd sync --delete-removed --limit-rate=288K --multipart-chunk-size-mb=5 --no-progress LOCAL_DIR s3://BUCKETSearched everywhere for an explanation/solution to this problem all I could come up with was a very terse

Quote:

An error occurred while doing I/O on some file.

After much playing with --verbose and --debug flags discovered that if I fed the data piecemeal directory by directory it would work. For some reason I then decided to double the very lowly transfer rate from 288K to 576K and it started to work.

Hope this helps someone.