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Slow SCP
Hi,
When I am transferring one file over SCP from Server A to Server B, it happens fast (average 10MBPS). However, transferring from Server B to Server A via SCP is super slow; 500 kbps max.
I have tried the transfers at different times of the day. Still, same result.
How can I troubleshoot the one-way slowness? Both run Linux. Different network providers.
Thanks!
Comments
Soes the slowness persist to any destination when server B is the source or just to Server A?
Is the disk busy in terms of reads on Server B or is Server A busy in terms of disk writes?
My money is on crappy peering.
I even tried with a different provider... Incoming to Server A is slow from another provider also. But, outgoing is fast.
Server A (receiver of slow files) is completely idle. Its a new server setup.
All providers are saying, I dont see any problems.
can you boot server A in to recovery mode and try it just to 100% rule anything out on the server (expect the same result).
After that gather tracert info both ways, ask the DC for a local test file (which will probably work fast) and then ask them why they think that 500kbps is not a problem.
It might also be worth testing things using wget to back things up.
So I submitted a MTR to and fro. Mid way one of the hops has some packet loss. Provider said since final hop had no loss nothing seems to be wrong. Hence I am at a loss on how to find out the root cause of the problem and get it resolved.
Thanks.
It's just with scp? Try rsync to see if the same happens if you don't want to test in rescue mode.
Hmm. I'll try. Thanks
Would you mind show us interfaces full ip configuration ?
Using winscp? Its a pile of shithouse. Use cyberduck
I am using command line scp. Both are Linux
How?
no offence but troubleshooting this sort of issue requires a degree of understanding, that degree far exceeds knowing how to show your interface configuration, or more to the point, even the knowledge that you could just google it.
I think you are best off just paying your DC staff to investigate for you or moving your server.
None taken. Is it just ifconfig op needed?
I'd check MSS/MTU setting on both servers and along the route (i.e. tracepath). This might be caused by packet fragmentation...
Also note that even then you might still not get an answer. I just moved 175 megabytes on a colocated server in Dallas to a colocated server in LA with both locations being colocated with the same company, and this transfer ran about 800 kilobytes a second.