Denis wrote:

I found the reason. It have nothing with WinSCP.
It is some VMWare problem with bridged network and connection to the VM on the same host.
Workaround is to disable hardware TCP fragmentation support on the network card (physical one).
On my card this is "Offload TCP_LargeSend" parameter.
Hope it helps to somebody.

Thanks for sharing this.

I found the reason. It have nothing with WinSCP.
It is some VMWare problem with bridged network and connection to the VM on the same host.
Workaround is to disable hardware TCP fragmentation support on the network card (physical one).
On my card this is "Offload TCP_LargeSend" parameter.
Hope it helps to somebody.

Denis wrote:

It does not help, but increases successfully transferred data size twice. Probably it works because of speed decrease. Now I found that limiting connection speed down to 4 Kb/s solves problem. It is better then nothing, now I can work, but it so slow :(

Interesting. Thanks for your feedback.

It does not help, but increases successfully transferred data size twice. Probably it works because of speed decrease. Now I found that limiting connection speed down to 4 Kb/s solves problem. It is better then nothing, now I can work, but it so slow :(

Can you try 5.0.5 again and disable Optimize connection buffer size
https://winscp.net/eng/docs/ui_login_connection

I have a problem with transferring files larger then ~20 Kb from WinXP to the CentOS installed locally on VMWare.

Details:
This side: WinXP SP3 Pro + all updates.
Other side: CentOS 5 under VMWare (bridged network).
Tried WinSCP versions: 3.8.2 (build 330), 5.0.5 (build 1782), FAR plugin 1.6.2 (based on WinSPC 4.1.9).
Tried modes: SCP, SFTP.

After transfer of some small amount of data, the transfer process is stuck and then gives timeout message. After such fail, on the other side appears partial file of size like 8192, 16384 etc. If data size is less then ~20Kb, after some delay transfer can succeed. If more then 25 Kb - no chance at all.

At the same time, I can without problems:
1) upload files to this VmWare CentOS from other computer in the network.
2) upload files to the other hosts (including CentOS 5) from my computer.

So, problem is restricted to the uploading files to the VmWare CentOS host on my local machine. And there is no problem in downloading files with WinSCP.

I have no idea, where I should look for problem source. I suspect it is not WinSCP fault, but may be somebody gives me some idea what I can try to solve this problem. I haven`t find anything helpfull with Google :(