Slow - and Weird!

Howdy Clever Peoples

I have two servers and notebook all on same Gig LAN, one an old Debian. From Windows XP / Dual Pentium notebook can transfer a 1 Meg binary file in the blink of an eye.

Have made a new Ubuntu Server 8.04, setup SSH, log in using SFTP (Same PC, same WinSCP settings etc!) same file takes 10 mins!!! Can download file off new server (once its there!) in a flash, so server NIC seems OK.

Was using WinSCP 406, upgraded to 407, same, upgraded 413, still same! The /etc/ssh/sshd_config files on the respective machines are largely identical, apart from upgrade(?) syntax changes. Protocol is SFTP(SCP), no key file, SSH protocl Ver 2. (Same for each shown with saved hovertip)

I also note the Ubuntu server transfers seem to hang with the transfer window frequently unresponsive, yet updated every multiple of seconds. They start off reporting very fast transfers (as expected) with typ speeds of 50,000B/s

Suggests something about ubuntu server?, perhaps setup, perhaps someone here can suggest?

Checking further both CPU's utilization are not at all touched by this, using task manager and top.

If I can help debug this I'd be pleased to do so.

Once you connect, please make sure that the same protocol was actually used on both servers.

martin wrote:

Once you connect, please make sure that the same protocol was actually used on both servers.

Thanks Martin, using WinSCP / Commands / Server Implementation they are identical, except for the differing SSH implementations and 1024 vs 2048 ssh-rsa keys. I doubt that key size change would make the difference I am noting?

Ubuntu:
Session protocol = SSH-2
SSH implementation = OpenSSH_4.7p1 Debian-8ubuntu1.2
Encryption algorithm = aes
Compression = No
File transfer protocol = SFTP-3
------------------------------------------------------------
Server host key fingerprint
ssh-rsa 2048 ...
------------------------------------------------------------
Can change permissions = Yes
Can change owner/group = No
Can execute arbitrary command = No
Can create symlink/hardlink = Yes/No
Can lookup user groups = No
Can duplicate remote files = No
Can check available space = No
Can calculate file checksum = No
Native text (ASCII) mode transfers = No
------------------------------------------------------------
Additional information
The server does not support any SFTP extension.

Older Screaming Debian!
Session protocol = SSH-2
SSH implementation = OpenSSH_3.8.1p1 Debian-8.sarge.4
Encryption algorithm = aes
Compression = No
File transfer protocol = SFTP-3
------------------------------------------------------------
Server host key fingerprint
ssh-rsa 1024 .....
------------------------------------------------------------
Can change permissions = Yes
Can change owner/group = No
Can execute arbitrary command = No
Can create symlink/hardlink = Yes/No
Can lookup user groups = No
Can duplicate remote files = No
Can check available space = No
Can calculate file checksum = No
Native text (ASCII) mode transfers = No
------------------------------------------------------------
Additional information
The server does not support any SFTP extension.

Hm. I do not know what else I can suggest you :-(

Thank you for your consideration. I was sort of hoping there might be a way to turn on a debug mode / logging mode that would show at what point the issue arose. I remain sort of interested to do that because it would surprise me if everyone got the same from ubuntu server 8.04 so there may be some issue I have yet to nobble! (Hardware comes to mind)
The anwser for me at this stage has been in using another OS, FreeBSD works fine and arguably better, although being a little more complicated to set up, despite that I have spent less time on FreeBSD than trying to get Ubuntu server to work.

The issue seems to be addressed in 4.1.4, I tried this as I noted these in the history:
# Bug fix: Automatic reconnect during transfer did not work occasionally. 72
# Bug fix: Local proxy was not working at all. 244
# Bug fix: WinSCP hanged when dummy protocol command was dispatched to keep session alive, while reconnecting.
I wonder if these were related to the problem?

Hi

I am having the same problem now after upgrading to the new version. B/s speeds now between two local computers on the same network.

G wrote:

Hi

I am having the same problem now after upgrading to the new version. B/s speeds now between two local computers on the same network.

Perhaps I was not clear enough, I was saying that 4.1.4 seems to have overcome the problem I was experiencing in the earlier versions. (4.0.6 through to 4.1.3) I now get LAN transfer speeds of ~2M/sec, not 100, but acceptably not 1K/sec or hanging. I look forward to the F2 key behaviour being addressed / reversed somehow, please! Are you using 4.1.4?

I do not have slightest idea what may cause performace change between 4.1.3 and 4.1.4, in either direction :?