Help with b2 chunk size and sync to backblaze

Sorry if this is a silly question, but I am really having a difficult time understanding how the chunk size and upload cutoff arguments are to be used.

I have some large files I want to upload to backblaze (backup archives +500GB in size. Here is the command I have constructed to run with.

rclone sync -v B: backblazeb2:bucket1 --exclude “/System Volume Information/**” --exclude “$RECYCLE.BIN” --b2-chunk-size=250M --b2-upload-cutoff=5000M --transfers=6

I expected to see the -v output to show chunks of files uploading and fairly quickly of 250M (1gpbs connection) But I do not. Any insight would be helpful!

Thanks!

This means that you want the b2 chunks to be 250M. Remember these are buffered in memory so you’ll need --transfers worth of them, ie 6*250M = 1.5G of memory.

This means that for files < 5000M you want them transferred as single files and not using chunked upload.

You’ll need -vv to see the chunks transferring.

Thank you kind sir. I was worried I had misinterpreted some of the documentation. I’ll try with the -vv to see if I get the type of feed back I am looking for.

The large files seem to spend a lot of time reading the disk but not transferring. I am assuming that this process has to read the entire size of the file on disk and then check the cloud version before transfers will start?

B2 needs the sha1sum of the file before uploading so rclone will be calculating that. This can take some time for very large files.

I am getting closer, but still getting a message on one of my larger files I am trying to upload. Reading documentation at b2 seems to say they support files up to 10TB. This file is well short of that.

File size too big: 5235605504 (400 bad_request)
2018/08/14 12:46:08 ERROR : B2 bucket Veeam1: not deleting files as there were IO errors
2018/08/14 12:46:08 ERROR : B2 bucket Veeam1: not deleting directories as there were IO errors
2018/08/14 12:46:08 ERROR : Attempt 3/3 failed with 1 errors and: File size too big: 5235605504 (400 bad_request)
2018/08/14 12:46:08 Failed to sync: File size too big: 5235605504 (400 bad_request)

Screenshot at: https://vgy.me/EzdFSl.png

Can you try with -vv --dump responses and see if that gives a clue?