What is the problem you are having with rclone?
Backing up to my general use AWS S3 bucket using rclone, any file greater than 290MB fails with error code "corrupted on transfer: sizes differ" and it reports that the destination has a file size of zero. This is happening consistently for every single file that is of this size. All smaller files upload without a problem. I have tried troubleshooting by adjusting multipart upload settings, chunk sizes, upload size cutoffs for when to start using multiple parts, enabling checksum verification for the uploads, etc. and nothing helps.
My inefficient temporary workaround has been to back up my directories excluding file sizes greater than 290M, and then using the web console to manually upload everything bigger. This is going to very quickly stop being an option I can even entertain as I run out of small files and move onto the 20+ terabytes of others that I need to upload, most of which average a size of 1GB or larger. So I’d REALLY love to get this working.
I was trying to research this problem on my own but other threads about it reported problems with the checksum, or the sizes differ error actually involved small amounts of bytes being off. I could not find a case like mine where the reported size of the file on the destination was always zero.
EDIT: it might actually be failing with anything larger than 250MB, I just found new failed uploads that were this size. However, an upload of 236MB worked just fine. I did my troubleshooting with 290MB however, so I will leave the commands I used as-is.
Run the command 'rclone version' and share the full output of the command.
C:\Program Files\rclone-v1.74.1-windows-amd64>rclone version
rclone v1.74.1
- os/version: Microsoft Windows 11 Home 25H2 25H2 (64 bit)
- os/kernel: 10.0.26200.8246 (x86_64)
- os/type: windows
- os/arch: amd64
- go/version: go1.26.3
- go/linking: static
- go/tags: cmount
Which cloud storage system are you using? (eg Google Drive)
AWS S3
The command you were trying to run (eg rclone copy /tmp remote:tmp)
rclone copy --fast-list "X:\BOOKS\NONFICTION" "remote:megaton-017135960107-us-east-2-an/MANUAL BACKUP/MEDIA/BOOKS/NONFICTION" -P
Please run 'rclone config redacted' and share the full output. If you get command not found, please make sure to update rclone.
C:\Program Files\rclone-v1.74.1-windows-amd64>rclone config redacted
[remote]
type = s3
provider = AWS
access_key_id = XXX
secret_access_key = XXX
region = us-east-2
endpoint = s3.us-east-2.amazonaws.com
location_constraint = us-east-2
acl = private
storage_class = STANDARD
bucket_acl = private
chunk_size = 64Mi
disable_checksum = false
shared_credentials_file = %USERPROFILE%\.aws\credentials
profile = aaron
upload_concurrency = 16
no_head = false
no_head_object = true
env_auth = false
upload_cutoff = 290Mi
copy_cutoff = 290Mi
might_gzip = true
use_multipart_uploads = true
A log from the command that you were trying to run with the -vv flag
2026/05/10 19:34:30 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload wrote chunk 7 with 41559768 bytes and etag "27cbc8c6633fa145d33e1ea8c92b61f1"
2026/05/10 19:34:30 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multi-thread copy: chunk 7/7 (402653184-444212952) size 39.634Mi finished
2026/05/10 19:36:11 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload wrote chunk 1 with 67108864 bytes and etag "a757389d6db2db72258e0ba2822bb5d5"
2026/05/10 19:36:11 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multi-thread copy: chunk 1/7 (0-67108864) size 64Mi finished
2026/05/10 19:36:21 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload wrote chunk 3 with 67108864 bytes and etag "f5a30427a8a02d6bf5a7395af2b7af28"
2026/05/10 19:36:21 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multi-thread copy: chunk 3/7 (134217728-201326592) size 64Mi finished
2026/05/10 19:36:23 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload wrote chunk 6 with 67108864 bytes and etag "547caf01e54ecd32cc6d26de7d996a07"
2026/05/10 19:36:23 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multi-thread copy: chunk 6/7 (335544320-402653184) size 64Mi finished
2026/05/10 19:36:27 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload wrote chunk 2 with 67108864 bytes and etag "96113f5fd75de16151e7aa0c6d396b87"
2026/05/10 19:36:27 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multi-thread copy: chunk 2/7 (67108864-134217728) size 64Mi finished
2026/05/10 19:36:28 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload wrote chunk 5 with 67108864 bytes and etag "26cfe041626d8c14934e9b8ffd65c38c"
2026/05/10 19:36:28 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multi-thread copy: chunk 5/7 (268435456-335544320) size 64Mi finished
2026/05/10 19:36:29 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload wrote chunk 4 with 67108864 bytes and etag "b143b2fa96f89a6caa929387c0f6a48e"
2026/05/10 19:36:29 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multi-thread copy: chunk 4/7 (201326592-268435456) size 64Mi finished
2026/05/10 19:36:30 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: multipart upload "8ljm2sQW2zYnPgGmyMTsO9UxXWp8ak94CToTEw0bsbrvNKLdu2Cbpocvv3Bby8AtXNmJPz6FjlhvEliFDgZOZjF0ZCKIsVi6odxQrGqwTSDx7WLPAHZ8p353zDrNL8qj" finished
2026/05/10 19:36:30 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: Finished multi-thread copy with 7 parts of size 64Mi
2026/05/10 19:36:30 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: size = 444212952 (Local file system at //?/X:/BOOKS/NONFICTION)
2026/05/10 19:36:30 DEBUG : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: size = 0 (S3 bucket megaton-017135960107-us-east-2-an path MANUAL BACKUP/MEDIA/BOOKS/NONFICTION)
2026/05/10 19:36:30 ERROR : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: corrupted on transfer: sizes differ src(Local file system at //?/X:/BOOKS/NONFICTION) 444212952 vs dst(S3 bucket megaton-017135960107-us-east-2-an path MANUAL BACKUP/MEDIA/BOOKS/NONFICTION) 0
2026/05/10 19:36:30 INFO : ART/THE ART OF/The Art of Rick and Morty/The Art of Rick and Morty.cbr: Removing failed copy
Please note, if relevant, that I first tried all of these commands without checksums or HEAD enabled (trying to reduce API call usage) and at first my upload/copy cutoff was much larger (set to 4GB). I reduced those sizes and enabled checksum and HEAD again trying to see if it would help with these uploads, but no such luck.