Failed file transfer resumes

When a transfer is interrupted, resumption fails when the file is large and more than 2gb have already been transferred. I assume this is a winscp bug - has anyone run across this?

I works for me. What server do you use? Can you post an error message?

martin wrote:

I works for me. What server do you use? Can you post an error message?

I used the titan FTP server and in fact it seems to break without retrying at the 2gb mark. I am trying again with a cygwin sftp server. The error was cryptic - error 4 and 6, but I did not save the exact text. Will rerun tests and get specifics. Thanks!

I am using titan because regular linux sftp has poor logging. Oh, sure, you can patch it, but it's still pretty abysmal. Titan has a nice set of options but I am flexible. If anyone out there has recommendations for a nice GUI that combines throttling, ip address restrictions, auto home dir creation, disk quotas, etc. please let me know!

Tried again against a cygwin sshd/sftp server, and sure enough, it broke at 2gb, and I'd guess it's winscp that's the problem. When I reconnected to try and resume, I saw a negative file size in the winscp window, so perhaps you have some 32bit signed int goodness around. So 2 sftp servers up, 2 failures. I am using a cygwin sftp client now to replicate.

FWIW, the error message I got was
Bad message (badly formatted packet or protocol incompatibility).
Error code: 5
Error message from server: Bad message
Request code: 6

From cygwin's sftp server.

I'll test it with cygwin. With Vandyke VShell it works.

Thanks for the quick response. FYI, kudos on WinSCP - it's a great client and very useful for a number of projects I have. Thanks!

Although I do have a question for you - why Borland? ( I poked around the source yesterday. )

I ran some more tests ( testing large file transfers takes some time! )
cygwin sftp client -> cygwin sftp server fails
winscp -> cygwin server fails
winscp -> Titan fails

Both file systems are ntfs. Titan is commercially supported and they claim that large files should not encounter problems, which is what makes me think it's probably WinSCP - although nothing is certain. Titan has a free download eval, or I can set up a server for you if you'd like to test.

I can get by by just splitting files pre-transfer to less than 2gb but am stubborn enough to want to find a solution. Thanks again for your help.

Although I do have a question for you - why Borland? ( I poked around the source yesterday. )

Why not? :-) I was the only RAD environment I had experience with at the time I've started with WinSCP project (5 years ago).

I ran some more tests ( testing large file transfers takes some time! )
cygwin sftp client -> cygwin sftp server fails
winscp -> cygwin server fails
winscp -> Titan fails

I have tried it on cygwin (OpenSSH for Windows) and it works. So it seems that it is rather server-releated (HDD filesystem or something).

> So it seems that it is rather server-releated (HDD filesystem or something).[/quote]

Odd. I have NTFS on both machines, and also many large files ( >2gb ) on both. Breaking at 2gb seems an odd coincidence. I am using sftp, not scp, if that helps.

I also find connections breaking during transfers when trying over the net rather than just over my local network. Will adjusting the timeout parameter help with this? If a connection is severed, is there an auto-reconnect option?

I also find connections breaking during transfers when trying over the net rather than just over my local network. Will adjusting the timeout parameter help with this?

That depends on reason why the connection breaks. Just try, you'll see :-)

If a connection is severed, is there an auto-reconnect option?

No.