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[all variants] High sshd CPU usage during sftp transfers

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http://ubuntuforums.org – I'm running Xubuntu 12.04 x64 on an AMD 64 X2 4200 dual core 2.2GHz machine. I'm connecting to it via SFTP from my Windows machine over my 100mbps LAN, using FileZilla. I noticed that when I transfer large files, sshd consumes a lot of CPU time: 1 transfer: Pegs one of my CPU cores at 100% and I only get around 80mbps transfer speed. 2 transfers: Two sshd processes running at ~60% CPU usage each, and my transfer speed reaches the full 100mbps. 3 transfers: Three sshd processes run at around ~45% CPU usage, and the transfer speeds seem to jitter whenever other processes need CPU time (I actual (Hardware)

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Submitted by colm on 09/14/2012

Stories similar to [all variants] High sshd CPU usage during sftp transfers

I am currently using a Server 2008 R2 box with IIS 7.5. I have IIS FTP+SSL setup and working properly with AD accounts. My issue lies in upload speeds. On a previous unix host FTP transfers were quick both with large files, and small files in any quantity.

I've setup a server which I've connected to multiple PCs in my workplace. Sadly, data transfer speeds are at max 3 MB/sec per connection which works out slow for file transfers, especially when transferring large files. I'm using Windows filesharing and the server is a Windows Server 2008 (2 Ghz CPU, 1 GB RAM) and the client PCs mostly running Windows 7.

I'm running Debian stable and I'm looking to establish the following environment for users in my 'sftponly' group:

jailed can transfer with SFTP can transfer with SCP cannot login interactively with SSH

From my experimentation and research, it seems that the following stanza in sshd_config gets me 90% there:

Match group sftponly ChrootDirectory /sftp/%u X11Forwarding no AllowTcpForwarding no

Hello, I am trying to figure out why I cannot sftp onto our aix6.1 machine.

We have a scheduled task that transfers a large file (~130 MB) between two Windows servers using the Windows command-line FTP program. It's painfully slow (taking about 30 minutes) and occasionally terminates before the transfer has completed.

Lots of old sshd processes 36 weeks 4 days ago

Hi,

I just did ps aux and noticed that there are lots of old sshd processes listed. I have the feeling those shouldn't be there.

Hopefully you guys can help and see if I've done something weird here, I'm trying to log in with a user I set up, FileZilla shows me:

Command: open "///@///" Command: Pass: ******** Status: Connected to /// Error: Connection closed by server with exitcode 1 Error: Could not connect to server

So, I went into auth.log and I see this:

Feb 12 11:08:49 sshd[12056]: Accepted password for /// fr

Hello. I've been trying to set up an ethernet connection between my Linux laptop and my wife's Mac laptop for the purpose of ssh-ing and scp-ing. (She wants me to transfer 50 G worth of files to her computer.) I've googled around for the last few hours, but I keep finding how-to's like this one, and I need more help than that.

Here's what I've done so far.

This is my first question here and i may not be very well versed with AIX too. But neverthless i am trying to solve the problem at hand and this is what i am stuck with.

We have an AIX 6.1 machine up and running. But the CPU usage as shown on topas seems to be always 100%. (user ~70% + kernel ~30%).