To ftp or to sftp
Article by Rampant author Laurent Schneider
Ftp is seen as an old-time unsecure
protocol. Many shops nowadays have switched or are switching to
sftp. I will try to point out some differences:
Compatibility: none. The protocol is
completely different. Multiple graphical clients however do
support both mode. But the basic “ftp” client will not work with
Ascii mode: only in ftp. In sftp, it is
always binary so there will be no conversion. Also no blocksize,
recordlength or primary/secondary space for your OS/390
Interactive mode: similar. you enter your
username and password, do cd, put and get. But to quit, by will
not work in sftp Use quit or exit instead
Batch mode: different. Most probably you
will end up setting a private/public key infrastructure for your
ssh connection and use scp (secure copy). If you are using a ssh
client like putty, it is possible to do something like pscp -l
user -pw password server:file .
Security: sftp is secure, ftp is not.
Speed: ftp is fast, sftp is slow!
Oh NOOOOOOO!!!!! What’s the point is
bringing something new if it is slower!!!
Ok, let’s try to download a 100m file:
time (echo "open dbsrv01
user oracle secret
100m"|ftp -n )
$ time scp -q oracle@dbsrv01:100m .
it is about 4x slower! Is there
anything we could do about it?
Well, maybe :
$ time scp -q -o
Compression=yes oracle@dbsrv01:100m .
ssh/scp/sftp have a compression mode. If
you are transferring your large files across a slow network,
this may be an interesting option to consider!