Hi Mark In a stretch cluster configuration you can replace host based mirroring software such as Veritas Cluster Volume Manager with ASM, i.e ASM can serve as host based mirroring software! But I cant find detailed stuff to explain how it works Hardware mirroring would be array based. Thanks -- LSC On 2/19/08, Powell, Mark D <mark.powell@xxxxxxx> wrote: > > I believe that when "host" based mirroring is in use in relation to ASM > that it means the host OS or hardware is performing the mirror function > outside of ASM so ASM is not mirroring the disk in this case. > > > -- Mark D Powell -- > Phone (313) 592-5148 > > > ------------------------------ > *From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto: > oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *LS Cheng > *Sent:* Tuesday, February 19, 2008 2:33 PM > *To:* oracle-l > *Subject:* ASM Host Mirroring > > > Hi > > Does anyone know how ASM does host based mirroring. For example we have > two storage arrays with 10 metres distance, two failure groups are created, > one per array. How does ASM mirror the extents? Network? Using the Cluster > Interconnect? Or a seperate Network? > > Cheers > > -- > LSC > > >