SFTP / I am not sure what to do at this point

Hello- this is sort of a hail-mary post.

I am a long time Duplicacy user now. I have about 10 people SFTP from all over the world into my basement.

My wife and I SFTP to the basement but also out to a remote computer across town.

My wife’s mac is the ONLY client that cannot seem to reliably SFTP to the remote computer. She SFTP’s fine to the basement server but when going to any remote server via Duplicacy SFTP - the data transfers stall at about 25%. They just stop. Log files don’t indicate anything… they just stop.

I have reduced down to 1 thread to keep things simple. I know my upload bandwidth is about 30 Mbps, and my Mac, same model, same O/S - can send just fine to the same remote destination. It is just her’s that stalls out. I have also tried two different remote computers…

I am not sure what to do… I guess I am considering trying to switch to a different transfer protocol like WebDAV just to see if that helps.

Any other thoughts?

THANK YOU!!!

Looks like as if some other network client (perhaps corporate on-demand VPN?) resets network connection on your wife’s Mac or changes gateway somehow. SSH/SFTP would just stall as a result.
Check what other connections are configured on her machine

Actually, you could do just that - capture routing table once SFTP works (netstat -nr) and then once it stalled. And compare.

As a side note - I would avoid webdav. SFTP is the best choice in terms of performance and reliability

Thank you for the tips.

OK on WebDav… I started to install a WebDav server on the remote unit but perhaps I will abandon that then.

I was also looking at Minio with the idea to try using the S3 protocol… but installing and getting Minio working seems a little more complex… I am not a sys admin or anything :slight_smile:

I guess this stemmed from the assumption that the issue could be caused by SFTP client or server, which I don’t think is the case: the server is fine since your other machine connects and the protocol itself is ancient and rock solid. Switching to WebDAV will only muddy waters by bringing WebDAV specific issues into the picture.

Let us know what you find out about the routing table when the stall occurs.

Also when stall occurs and you cancel and restart backup does it work? If so, it’s very likely the issue is due to network config change.

You may want to enable sftp logging on the server to see if you can find anything there. Here is an tutorial on how it is done: Logging sftp commands - Red Hat Customer Portal

If you want to try a different protocol I would suggest minio: GitHub - minio/minio: Minio is an open source object storage server compatible with Amazon S3 APIs.

Thanks all for these tips. I will be trying to work through them to see what I can learn and will report back.

Brief update. I noticed that it was often hanging on files in the Mobile Sync folder… which are iPhone backups.

I decided I didnt need to back up anything in the Libraries directory tree so I put that in the filters file as an exclude.

upon running the backup again… this time I made it to about 98% before it hung… I ran it again and it completed… first time ever to the remote computer.

I have captured the netstat -mr results but am not quite sure yet what I am looking for… will continue to investigate this and keep you appraised. Thanks again for the input so far.

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I thought I had this problem licked but not sure now.

I actually am wondering if it is locking up in the packing phase and not during SFTP… I am not sure on that though. It doesn’t make sense that this would be the case since I NEVER get a fail when backing up locally.

Anyway… still testing things… just an update.