[DRBD-user] primary/primary with ext2 not updating real-time

[Theophanis Kontogiannis]

Absolutely understood

Thank you all for your valuable time and assistance.



-----Original Message-----
From: Graham Wood [mailto:drbd at spam.dragonhold.org]
Sent: Wednesday, February 27, 2008 7:33 PM
To: drbd-user at lists.linbit.com
Subject: RE: [DRBD-user] primary/primary with ext2 not updating real-time


----- Message from theophanis_kontogiannis at yahoo.gr ---------
> I am a bit confused since I believed that GFS itself, groups together in a
> single large file system, physical disk space, spread in the network.
>
> But it really does this or not (in which case we need DRBD)?
GFS requires an underlying block device that is accessable to all
nodes.  You can do this via GNBD (which does something similar to
DRBD, but in a different way), but you still need SOMETHING to do that.

The way to look at it is as a layered arrangement.  To have a shared
filesystem you need a shared block device and a shared filesystem:

Shared Block Devices:
   SAN
   Dual attached SCSI
   GNBD
   DRBD
   iSCSI

Shared Filesystem:
   gfs
   gfs2
   gpfs
   ocfs
   ocfs2

----

There are probably more options for both, but the important thing to
remember is that you need BOTH to get a truely shared filesystem.

Graham