openssh unix dev - Feb 2007 - SFTP: a new command to get filesystem size/free space

I am using sshfs with FUSE to mount a remote directory over ssh/sftp (on linux).

It would be nice if df could be able to show the total size/free space
of the mounted directory.

I am aware that returning size/free space would have some limitations.
For example, if a subdir of the mounted directory has another
filesystem mounted on the remote server, this can not be represented
simply.

However, I still think that a simple implementation could be useful.
My idea is to simply return the total size and free space of the
current working directory.

Would you accept patches implementing this?

Please CC me, I am not on this list.

Regards, Thue

PS: does the openssh sftp implementation conform to
http://www.openssh.org/txt/draft-ietf-secsh-filexfer-02.txt ?  If not,
is the protocol described elsewhere?

Thue Janus Kristensen wrote:
> I am using sshfs with FUSE to mount a remote directory over ssh/sftp (on
linux).
> 
> It would be nice if df could be able to show the total size/free space
> of the mounted directory.
> 
> I am aware that returning size/free space would have some limitations.
> For example, if a subdir of the mounted directory has another
> filesystem mounted on the remote server, this can not be represented
> simply.
> 
> However, I still think that a simple implementation could be useful.
> My idea is to simply return the total size and free space of the
> current working directory.
> 
> Would you accept patches implementing this?
I don't speak for the OpenSSH team but given the history of previous 
random patches I doubt it will be accepted in any fashion.
> 
> Please CC me, I am not on this list.
> 
> Regards, Thue
> 
> PS: does the openssh sftp implementation conform to
> http://www.openssh.org/txt/draft-ietf-secsh-filexfer-02.txt ?  If not,
> is the protocol described elsewhere?
Afaik, yes, OpenSSH supports SFTP version 3, and probably won't support 
anything else anytime soon.

Your feature can probably be easily implemented via the SSH_FXP_EXTENDED 
message.  Though an SSH subsystem for drive metrics might be interesting.

-- Jason

On Sun, 18 Feb 2007, Thue Janus Kristensen wrote:
> I am using sshfs with FUSE to mount a remote directory over ssh/sftp
> (on linux).
>
> It would be nice if df could be able to show the total size/free space
> of the mounted directory.
>
> I am aware that returning size/free space would have some limitations.
> For example, if a subdir of the mounted directory has another
> filesystem mounted on the remote server, this can not be represented
> simply.
>
> However, I still think that a simple implementation could be useful.
> My idea is to simply return the total size and free space of the
> current working directory.
>
> Would you accept patches implementing this?
We would consider them, sure - but we can't promise we will like
them enough to accept them before we see them :)

The patch would have the best chance of being accepted if it used the
SSH2_FXP_EXTENDED protocol message and followed the message format of
later filexfer drafts for the encoding of filesystem information (IIRC
recent filexfer drafts have a statvfs-like method).

The patch would also need to implement support for it in the sftp
client, so we can have a way to test the method in our regress tests.
> PS: does the openssh sftp implementation conform to
> http://www.openssh.org/txt/draft-ietf-secsh-filexfer-02.txt ?  If not,
> is the protocol described elsewhere?
IIRC we actually implement filexfer-03, but the draft for it seems to
have fallen off the net.

-d