Can't sync through Tailscale

[Mohza]

Hi,
I'm trying to transfer files from a mapped network drive connected via Tailscale, and while that works well via the explorer somehow FFS can't copy for more than a few seconds before the transfer rate drops to 0 and eventually displays an error message (ERROR_UNEXP_NET_ERR:An unexpected network error occurred. [CopyFileEx]).
I don't get why it works through explorer but not with FreeFile Sync.
Any idea what would be the problem?

[ravishahani]

Just a guess, but maybe you have Volume Shadow Copy enabled? That would be a problem since it only works on local drives.

[John1234]

Hi,

What operating system are you on and what are you mapping to? Perhaps I can try and duplicate this because I also have tailscale installed.

[Mohza]

Hi,

What operating system are you on and what are you mapping to? Perhaps I can try and duplicate this because I also have tailscale installed.

Hi!
thank you for your reply and sorry for the delay, I was away for a while.
I'm on Windows 11 and mapping a distant Synology NAS, via Tailscale.

[Mohza]

Just a guess, but maybe you have Volume Shadow Copy enabled? That would be a problem since it only works on local drives.

Hi, thanks though this option isn't enabled

[John1234]

Ok, sorry I should have been more specific. When you map the drive to the nas are you doing it with what protocol SMB or SFTP?

First do this:

Tip: Run tailscale status in your command prompt. If you see relay next to your NAS connection instead of direct, your speed will be significantly throttled regardless of which protocol you choose. Improving your NAT settings to get a direct connection is the single best thing you can do for performance.

SMB can be very chatty and it's not the best over a low latency Network.

SMB it's probably not going to work as well as SFTP. You can map a drive even using SFTP with a utility program like rclone or air live drive.

You're suggesting I think that the server is not located in the facility where you're at but someplace else on the internet?

Have you ever heard of or know about an app called iperf?

You can run it on Windows and Linux so it will run in your environment.

Basically what it does is test bandwidth from your location to the other and you can test the performance from your windows 11 machine to the NAS server over tailscale and see what the results are. It will give you a good Baseline to determine whether or not free file sync will work.

[Mohza]

Ok, sorry I should have been more specific. When you map the drive to the nas are you doing it with what protocol SMB or SFTP?

Thanks for your reply!
I'm using SMB, I used SFTP for a long time but wanted to switch to SMB via Tailscale for security reasons.

The connection to Tailscale is direct, and what puzzles me is that copying large quantities of files through windows explorer to or from the mapped drive works well, but it looks like the connection closes quickly when I do the same via Freefile Sync.

[John1234]

Hi,

Ok. You have tailscale which gives you an IP address to your internal computer but not an SMB connection.

What software are you using to mount the SMB share.? I might be able to give you some suggestions.

[Mohza]

Hi,

Ok. You have tailscale which gives you an IP address to your internal computer but not an SMB connection.

What software are you using to mount the SMB share.? I might be able to give you some suggestions.

Hi, sorry for the late reply, and thanks a lot for yours!
My NAS is a Synology, so I created the SMB share with the NAS OS : DSM, and the distant machine I use to access and backup (from and to) is on Windows 11, so the SMB share is mapped on a drive letter in there.

I've also tried using SFTP with Freefile Sync, by opening SSH on my NAS, which works a little better but very unstable, the connection keeps shutting down and restarts after 10 or 20 seconds.

Edit : Also I've tried using Rclone to see if that worked better, but I have the same problem, connection shuts down at some point (while using the mounted SMB share, no SFTP).

[Hemps]

I also Synology and I sync to another Synology offsite, under Task Scheduler I had to add -
Enable Tailscale Outbound
User - Root - Boot Up

Task Settings:
Run command
/var/packages/Tailscale/target/bin/tailscale configure-host; synosystemctl restart pkgctl-Tailscale.service

[Hemps]

Syncovery has a DSM app, free for single Scheduled task - powerful software, I use both

[Mohza]

I also Synology and I sync to another Synology offsite, under Task Scheduler I had to add -
Enable Tailscale Outbound
User - Root - Boot Up

Task Settings:
Run command
/var/packages/Tailscale/target/bin/tailscale configure-host; synosystemctl restart pkgctl-Tailscale.service

Thank you! That seems to be the solution, I have a much better transfer rate and no connection interruptions anymore.