[Dirvish] A conceptual doubt

[Leopold Palomo-Avellaneda]

A Dimecres 04 Juny 2008, Eric Searcy va escriure:
> On Jun 4, 2008, at 7:06 AM, Leopold Palomo-Avellaneda wrote:
> > Hi,
> >
> > changing my current configuration using nfs (local) to another one
> > with rsync
> > and I have realised that probably I have a missunderstand the dirvish
> > program. So, I would like to ask you if I have done a big mistake.
> >
> > I have a box (ris) with the /home of my users. I have another box
> > (ulises)
> > where I would like to put the backup files. If I mount (nfs) the
> > partition
> > from ulises to ris, and I run dirvish in ris, I can do a local
> > backup, as I
> > have done.
> >
> > But,  but reading again the documentation I have found that, if I
> > want to use
> > my transport as ssh, I would need to run dirvish in ulises, not in
> > ris,
> > because the server is the box where the backup is stored and the
> > client is
> > the box where I take the files from.
> >
> > Is this correct? Or can I run dirvish in one box and store the files
> > in
> > another box using ssh?
>
> You are correct in your reevaluation of how it works.  Dirvish is
> meant to be used on the backup server (it does `pulls', not `pushes').

Ok thanks to confirm it. Probably I didn't understand the documentation, but 
some lines about it would help to the new users.

> The reason you can't push is because Dirvish depends on having
> information about inode numbers for hard-links, which you can't do
> when you're pushing the data elseware.  The only way (I can think of)
> to save the files remotely is what you were doing first: mount the
> remote drive via NFS (NFS preserves inode information).  In theory,
> you're still doing a `pull'---just from one location on the virtual
> filesystem to a second location which happens to be mounted NFS.
> Assuming you can optimize your NFS options and network as was
> discussed in the previous thread, there isn't a reason you can't do
> this.  

the main problem is that many times is slow and some people in the list 
commented that the best way to do it is by rsync.

> But if you can toss a few perl scripts on ulises (which is all 
> dirvish is, after all) and run them via cron, then you can do a pull
> over rsync.

the main problem is that I have to port perl. But, well, it could be 
interesting. I have always thought that this kind of little boxes with an arm 
have a lot potential for this kind of job.

Anyway, thanks for the information.

Best regards,

Leo