NFS Question

[rdp at talisman.mv.com]

On Thu, 29 Aug 2002, John Abreau wrote:

> Rich Payne <rdp at talisman.mv.com> writes:
> 
> > How many clients are you talking about? I would strongly reccomend 
> > looking into some sort of network attached storage device. We use Network 
> > Appliance machines. At my previous employer we started out with a pair of 
> > Suns and hardware raid 5, then went over to the NetApps. They just serve 
> > files for a living, and they do it well.
> 
> I'd have to agree with this. Once you get past the sticker shock, the 
> NetApp appliances are awesome. I found them to be fast and reliable, and 
> the snapshot feature is a lifesaver. At any point in the filesystem, you 
> can access a read-only ".snapshot" directory to recover older files. 

Yes, they are a bit expensive I admit, but then again, what's your data 
worth to you?
 
> If you delete a file, or overwrite it, there's a copy in .snapshot/hour0/
> to recover it from. If I recall correctly, the system retains 7 hourly and 
> 7 nightly xnapshots by default. So you can always recover a file to its 
> previous state from 1 hour ago, 2 hours, etc, and 1 day ago, 2 days ago, 
> etc.

It's actually configurable by the administrator. You can choose how many 
shanpshots to keep, how often to take them and how much disk space they 
can take up.
 
> The snapshots are actually pointing at the same inodes that the main file 
> used; if a file hasn't been changed for at least a week, then all the 
> snapshots are sharing the same inodes for that file.

One interesting thing I found out about the NetApps is that the physical 
position of each disk isn't important. You can take all the disks out, put 
them back in a different order, even in different shelves and when you 
power the box back on it will find everything and go on it's way!

-- 
Rich Payne
http://talisman.mv.com