HP StorageW orks 3 Data Cen t er R eplication W hite paper T ab le of con t en t s E xecu t iv e s umm ar y............................... ................................................................................................ 3 T h e HP S t orageWor k s 3 Dat a Ce n t er Re pl ic at io n s ol u t ion ......................................................................... 4 HP St ora ge Work s X P Continuou s Acc es s Sy nc hr on ou s ............................................................................. 5 HP St ora ge Work s X P Continuou s Acc es s Asy nc hr on ou s ........................................................................... 6 HP St ora ge Work s X P Cont inu ous Acce s s Jour nal.. ................................................................................... 8 R e co v e ry po in t ob je ct iv e..................................................................................................................... 10 R PO equ al t o 0 .............................................................................................................................. 10 R PO gr ea t er t ha n 0 ........................................................................................................................ 10 R e co v e ry t im e ob je ct iv e...................................................................................................................... 10 R T O b et ween one an d fiv e m inu t es .................................................................................................. 10 R T O of one hour or m or e ................................................................................................................ 10 T he pr ior Multi-Sit e D is as t er T olerant S ol u t ion (MSDT)............................................................................. 11 3DC wit h HP St orage Work s X P Cont inu ou s Acc es s Jou rn al con figu rat ions.... ............ ... ........................ ... .. 12 Compar ing cas cad ing and m u lt i- t arg et c on figu rat ion s ........................................................................ 13 De t aile d rules and res t ric t ion s for 3DC configu rat ion s ............................................................................ 15 HP St orage Work s X P Cont inu ous Acces s Jour nal and m irro r un it de sc ript ors. ... ..................................... 15 A v olume can only hav e on e sou rc e ................................................................................................. 18 R ep lica t ion pair s ind ep en de nt of e ach ot he r...................................................................................... 20 Su spe nding a down st ream link bef ore t he ups t ream link goes out of or der. .................... .. .......... .. ......... 21 3DC fa ilov er and failback ac t ion s w it ho ut a t hird link ............................................................................ 23 Act ion 1: T ran sit ion fr om a cas cade d t o m ul t i- t arge t con figu rat ion.... .............................. ... ................... 25 Act ion 2: Tran sit ion from a m ul t i- t arge t t o cas cade d con figu rat ion.................................. ... ................... 26 Act ion 3: Casc ade d con fig u rat ion da t a cent er f ailu re......................................................................... 27 Fa ilbac k t o DC1 aft er a cas caded c on figuration failov er ..................................................................... 28 Act ion 4: Mult i- t arget configurat ion dat a cen t er f ailu re ....................................................................... 29 Failbac k t o DC1 aft er a m u lt i-t arge t con figu rat ion f ailov er t o DC2.. ........................ ... ........................... 30 Act ion 5: Mult iple dat a ce nt er fail ure s .............................................................................................. 31 Fa ilbac k t o D C1 af t er a mu lt iple DC fail u re....................................................................................... 32 T he bene f it s of t he op t ional third data lin k ............................................................................................ 37 Act ion 6: Using t he opt ional t hir d link............................................................................................... 39 R ec ov er y aft er t he us e of t he opt ional t hir d dat a l ink ................................. ... ........................ ... ............ 43 Other configura t ion op t ion s ................................................................................................................ 50 4D C con fi gu ra t ion ......................................................................................................................... 50 A 3DC con fig urat ion wit h fo ur cop ies ............................................................................................... 51 1