On Sun, Jul 22, 2007 at 11:06:59AM +0200, Jan Engelhardt wrote: > > On Jul 22 2007 00:43, Lars Ellenberg wrote: > >On Sat, Jul 21, 2007 at 11:17:43PM +0200, Jan Engelhardt wrote: > >> On Jul 21 2007 22:38, Lars Ellenberg wrote: > >> > > >> >We implement shared-disk semantics in a shared-nothing cluster. > >> > >> If nothing is shared, the disk is not shared, but got shared-disk > >> semantics? A little confusing. > > > >Think of it as RAID1 over TCP. > > And what does it do better than raid1-over-NBD? (Which is already N-disk, > and, logically, seems to support cluster filesystems)
DRBD has built-in logic to track which copy of the data is the most recent. DRBD has resource-level-fencing in place (though we can improve on that). DRBD deals with concurrent writes of the participating nodes correctly. "N-disk" is not the question, you can stack drbd on top of md, lvm, anything. N-nodes is the interessting thing. -- : Lars Ellenberg Tel +43-1-8178292-0 : : LINBIT Information Technologies GmbH Fax +43-1-8178292-82 : : Vivenotgasse 48, A-1120 Vienna/Europe http://www.linbit.com : - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
