scp and SGI DMF

[Chris Rapier]

Peter Stuge wrote:
> On Tue, Feb 28, 2006 at 03:58:27PM -0800, Iain Morgan wrote:
>> This causes DMF (the HSM) to recall the file from tape and the scp
>> hangs until it is successfully recalled.
> 
> Oh.

I think we saw problems like this with our tape silos as well. Its not 
something that most people have to deal with though which sort of makes 
it an orphan problem. So unless it can be argued that truncating a file 
before overwriting the file is correct behaviour I don't see it getting 
into the code base. One thing I'm wondering though - what would be the 
effect of not using a switch and just making truncate the default 
behaviour? It looks like its the default behaviour in sftp as it is. 
Anyway, something like this seems to be a pretty straightforward patch 
that only would need to be implemented on the NASA servers.

>> So, I'm wondering if there would be any interest in either adding
>> (yet another) command-line option to add O_TRUNC to the open()
>> flags when writing a file
> 
> I doubt this will ever happen. scp is only maintained for backwards
> compatibility with rcp.

See, I've never been convinced that this is the right way to handle SCP. 
   A lot of people use because its easy and straightforward. So I'm not 
sure its best to relegate it to enforced stagnation because it was 
originally envisioned as a drop in replacement for rcp. Thats just me 
though.