Re: [Proftpd-user] mod_sftp slowness - how can I track this down

On 2/17/21 4:37 AM, Matus UHLAR - fantomas wrote:

> > On 16.02.21 13:47, Michel van der List wrote: I recently
> > upgraded a machine to RedHat 8 and used the provided proftpd
> > rpm. This installs version 1.3.6e with some patches. I use the
> > mod_sftp module to provide access to a small number of people.
> > Prior to this version of the OS, on RedHat 7, this worked just
> > fine (version 1.3.5e). However, on this version, browsing
> > directories and accessing file using the OpenSSH_8.4 sftp
> > client is dreadfully slow.
>
> what exactly is slow, connecting, transferring files, listing
> directories?

Just browsing directories. I send a few follow ups that indicate
that the fsio module (or it's interaction with RedHat 8) may be
the issue. I'll look into that more today.

> is it also slow when trying plain ftp?

I did not look into that. I'm just trying to upgrade an old
configuration that had been in use for a *long* time.

> > I tried bunch of things, such as FSCachePolicy, FSOptions,
> > turning off SFTPExtensions, different advertized SFTPDigests
> > and SFTPCiphers, changed channelWindowSize, channelPacketSize,
> > but nothing seems to help. I turned on the Tracelog but that
> > did not tell *me* anything, though there's information there
> > that I don't understand.
> >
> > I then created an updated rpm for version 1.3.7a and I get the
> > same thing.
> >
> > Before I go off and downgrade to 1.3.5e (which I'd have to
> > recreate an RPM) I'm curious to know if there's anything I
> > can do to track this down. Of course I'm also curious if
> > downgrading would fix this anyway, or if there's something
> > else that's getting in the way.
>
> > SFTPExtensions -checkFile -copyFile -fsync -vendorID
> > -versionSelect -posixRename -spaceAvailable -statvfs -hardlink
> > -xattr
>
> did you just disable everything in attempt to make it faster?

Correct. I *thought* this was an issue with the encryption but
I'm becoming convinced that's not the issue.

> > SFTPDigests hmac-md5 hmac-sha1 hmac-sha2-256 hmac-sha2-512 \
> > hmac-ripemd160 hmac-sha1-96 hmac-md5-96 [email protected] \
> > [email protected]
> > SFTPCiphers aes128-cbc 3des-cbc blowfish-cbc cast128-cbc \
> > arcfour128 arcfour256 aes192-cbc aes256-cbc aes128-ctr \
> > aes192-ctr aes256-ctr
> > SFTPCompression on
>
>I would start with disabling compression then I'd disable CBC
>ciphers, md5 and sha1 digests.

Actually, in my latest test, I just went back to all defaults and
none of that made a difference.

Thanks for the response.



_______________________________________________
ProFTPD Users List   <[email protected]>
Unsubscribe problems?
http://www.proftpd.org/list-unsub.html