Syncing big files

[Loki188]

Hello,

I have question about syncing big files, I'm talking 15+ GB/file. I have this setup -> Main Synology, Backup Synology in remote location and Proxmox Server (in the same remote location as Backup Synology) running Ubuntu VM. Ubuntu VM has install FFS and has Backup Synology connected via CIFS/SMB and Main Synology connected via WebDAV. When I try to sync this big files I can see that free space on VMs main partition start to go down.

Am I assuming correctly that FFS in this setup is first downloading it as some temp file and then uploading it to the target share? This would mean that I would need to increase size of the VM's disk so it would ble able to take largest file that I can anticipate (around 70GB)?


Thank you for you help, I appreciate it. :-)

[Zenju]

FreeFileSync copies using a small memory buffer and doesn't use temp files.

[Loki188]

Ok, so it would just buffer small ammount and then transfer that to the target?

I'm seeing different things though. I wanted to sync/copy 18GB file. VM that is running FFS only has 25GB disk with 13GB of free space. In the picture you can see that when I first ran "df-h" command, it was before I launched FFS Sync. Second one is after few hours when 76% of that 18GB file was "copied" and you can see that most of the free space on that VM disk is gone - 93% is used.


https://ibb.co/QPFgnMs

What's going on?

Thanks.

[Zenju]

The disk space usage during copy is certainly not caused by FreeFileSync. Perhaps the webdav or SMB mount driver is buffering.

[Loki188]

Thank you Zenju. :-) In the end I have bitten the bullet and increased size of the VM's disk and it synced as it should.