Re: Hammer or ZFS based backup, encryption

[Jasse Jansson <jasse@xxxxxxxxxxxxx>]

On Feb 23, 2009, at 8:10 AM, Bill Hacker wrote:

> Freddie Cash wrote:
> > On Sat, Feb 21, 2009 at 10:39 AM, Csaba Henk <csaba.henk@creo.hu>  
> > wrote:
> > > I need to setup a backup machine, and I intend to utilize today's
> > > snapshotty filesystems (which boils down to Dfly+Hammer or FBSD 
> > > +ZFS --
> > > btrfs is not there yet, and I don't feel like dwelving into  
> > > Solaris).
> > > Set up such an OS with such an fs, and backup by syncing to the
> > > snapshotty fs and create a snapshot.
> > >
> > > I wonder about the following things:
> > >
> > > 1) Any idea how does this approach scale related to more  
> > > conventional solutions,
> > > like rdiff-backup or dump(8)? I see the the pros, but are there any
> > > cons? How effective is taking regular snapshots space-wise?
> > >
> > > 2) Is there any practical argument for choosing between Dfly 
> > > +Hammer and
> > > FBSD+ZFS? (Feel free to give biased answers :) )
> > >
> > > 3) I'd like to encrypt stuff, either at device or fs level. For
> > > FreeBSD there is geli(8). I haven't found anything for DragonFly.
> > > Is there any way to get at it on DragonFly?
> > We do this at work, using FreeBSD 7.1 and ZFS, for backing up over 80
> > remote Linux and FreeBSD servers, and 1 Windows station.  We have two
> > servers, one that does the backups every night, and another that
> > mirrors the backups during the day.
>
> *trimmed* (description of a quite decent ZFS approach)
>
> > After the initial rsync of a server, which can take several days  
> > as it
> > can easily max out an ADSL link's upload bandwidth, the daily run
> > takes about 6 hours, most of which is waiting for rsync to generate
> > the file listing.
>
> *snipped*
>
> But there we are, Startup 'seeding; is unavidable, but  
> thereafter ... among other things, looking to reduce the reliance  
> on rsync (and similar CVS'ish or git'ish techniques) having to  
> 'inventory' stuff at a high per-file level that a 'hammer mirror- 
> stream' (or GMIRROR to networked RAID) could do 'as you go along'  
> at a lower level - closer to the actual blocks as they are being  
> written.
>
> How, and how well, would ZFS handle redundant pools on separate sites?
>
> And can that be a streaming process - even if that means the  
> redundancy target is r/o for 'the duration', as a hammer slave  
> would be?

I have not tried it myself, but there is a ZFS send/receive command,
that might do the trick.





Kaiser Jasse -- Authorized Stealth Oracle

The axioms of wisdom:
1. Go the SPARC way of life
2. You can't conquer the universe without the knowledge of FORTRAN
3. In the Unix realm, 10% of work fixes 90% of the problems