DRBD (was: MerriLUG Nashua ...)

[VirginSnow at vfemail.net]

> Date: Mon, 23 Jun 2008 20:26:43 -0400
> From: "Kenny Lussier" <klussier at gmail.com>
> Cc: gnhlug-discuss at mail.gnhlug.org

> >  What's DRBD?
> >
> >  (Yes, I can use Google.  This is actually a cleverly disguised ploy
> > intended to foster discussion on the list.  (Oh, drat, now it's not
> > cleverly disguised anymore!))
> >
> 
> DRBD is a way of doing network-based block devices. It's used to do network
> RAID 1 in HA clusters. You set two system up and dedicate a particular block
> device to be the drbd block device. Then, when you write to one, it goes
> over a private network and writes to the other. It keeps the data in the
> cluster synchronized. I used it a few years back in conjunction  with Linux
> HA to build an HA NFS server. It was fairly simple to set up and get going.
> I would say that it has been surpassed by GFS these days, though.
> 

Does this DRBD have any advantages over the NBD (Notwork Block Device) +
MD/software RAID supported by the Linux kernel?