fixing my FTP (slow download speed)

[CuddlyBunny]

Hi,

I've been googling around for a while because my download speed for single large files with FileZilla isn't quite where I want it to be.
(1,5mb/s on a 100mbit downstream connection with a 100mbit upstream dedicated server from Kimsufi, which is as far as I know one of the companies owned by OVH)

So far I've been told (by various sites) to use an FTP client that supports segmenting until I came across this discussion in a thread on the FileZilla forum.
Now I'd like to keep using FileZilla and not use some random FTP client just because it supports segmented FTP.

I use SFTP and I really have no idea of the FTP configuration of my Debian server.
I just slapped it on there with some apt-get command and followed a few instructions.
I know my way around my server, just not the FTP part.

So I'd be very thankful if some of you could guide me through finding the issues that create the slow download speed and help me fix them.
I'd do it myself with the might of Google but in this case I really just have no idea of FTP setup on Debian and I believe it'd be a challenge to hard for me on my own.

Greetz,
- Bunny

PS: Why don't you support Gmail? I love Gmail!
I was under the impression they check their users authenticity quite well since you have to give them your phone number and submit the code they send you.

[botg]

What's the latency to your server during a transfer?

[CuddlyBunny]

No idea how to check that within FileZilla but if I just ping it during a transfer with cmd it's at around 30ms.

[botg]

Latency looks fine, that's not the problem.

Which SFTP server software is the server running?

During a transfer, what is the CPU usage of both client and server?

[CuddlyBunny]

Not sure about the SFTP server software. I believe it's internal-sftp with sshd. (If that's the answer you're looking for.)
Hard to figure out anything about the sftp version since the "sftp" command doesn't have an option for version information.

CPU usage of the server during a transfer is at ~15%. CPU usage of the client is at ~7%.

[boco]

Could be the fact alone that it's SFTP. SFTP is not a particularly fast protocol, unfortunately. CPU values are OK.

You might have more luck using FTPS Explicit, though.

[CuddlyBunny]

So FTP should present better results? Are there any steps I should take before testing this?
(Other than allowing non-SSH connections to make standard FTP usage possible of course.)

[boco]

FTP (as dedicated File Transfer Protocol) usually provides more performance than SFTP (which is a subset of SSH2 that's designed rather for remote shell than dedicated file transferring). The security of FTPS Explicit and SFTP is comparable.

You need an FTP server running on the target, with support for FTPS (including modern cipher suites/algos) and UTF-8 (i18n). Further support for MFMT (setting remote timestamps after upload) and MLSx (standardized machine-readable listing format) are a plus. On Linux, many of the available packages should offer support.

Other than that, it's a matter of forwarding allowing the proper ports (listening port and data range) and telling the server to return the correct IP when asked. The Network Configuration Guide is written for FileZilla Server on Windows, but large parts of it apply to any other FTP setup, too.

FileZilla test site: https://ftptest.net. It also has further help available.

[botg]

I don't see it mentioned yet: Which version of FileZilla are you using?

[CuddlyBunny]

I'm using FileZilla 3.14.1.

So I'm currently using the default SFTP server that comes with Debian. At least that's what I think.
The more I think about the less I actually recall installing any specific FTP package on my server.

I've done some research on which FTP packages are recommended and came to these two:

https://security.appspot.com/vsftpd.html
https://www.pureftpd.org/project/pure-ftpd

Heard of any of the two? Can you recommend one of these? If I recall correctly I've seen some people use vsftpd while reading guides and
forum posts and such to setup my server. Maybe I'll just go with that then, although the configuration of Pure-FTPd looks extremely quick and easy.

Greetz,
- Bunny

[boco]

From what I remember, vsftpd is the better one. vs=very secure

[botg]

I'm using FileZilla 3.14.1.

So I'm currently using the default SFTP server that comes with Debian.

Transfer speeds shouldn't be an issue in this configuration.

Unless you have manually configured a speed limit in FileZilla, I don't see why you are getting such slow transfers.

[CuddlyBunny]

I am using SSH though and denying any connections over the standard FTP port. So basically I'm allowing SFTP connections over the SSH port. Which configuration would create slow transfer speeds? I don't have any speed limits active in FileZilla.

[xeon]

OVH is well known for running many of their peering points at or near capacity, it wouldn't surprise me if this was simply a matter of congestion. It would certainly explain why a lot of the feature requests for segmented downloads come from people with servers on OVH's network.

[botg]

And yet, due to the extra overhead of segmented transfers, the total speed across all users would just further decrease. The only solution for congestion is to buy bigger pipes.

Users need to stop throwing money at providers that don't invest in infrastructure.