Ok doke,First let I make it clear: Adding a disk with force should be avoided, mainly by all the rebalance involved. The best choice, if you has “time”, is to just put disks online, like:1) ALTER DISKGROUP ONLINE DISK ; or2) ALTER DISKGROUP ONLINE DISKS IN FAILGROUP ; or3) ALTER DISKGROUP ONLINE ALL;But, the post is aboutadding back to DG the dropped disks.Let’s imagine, to undestand my situation, you lost the contact with one of your two site storage… In this example, represented by failgroup FGAUX. You would see the disks like this:SQL select name,failgroup,state from v$asm_disk a where state NORMAL;NAME FAILGROUP STATE------------------------------ ------------------------------ --------_DROPPED_0000_DGDATA FGAUX FORCING_DROPPED_0001_DGDATA FGAUX FORCING_DROPPED_0002_DGDATA FGAUX FORCINGSo, you know your disks by the name pattern (0 are FGMAIN and 1 are FGAUX, the problematic). You can do something like:[rootdatabase-host ~]# /etc/init.d/oracleasm listdisks |grep DGDATADGDATA001DGDATA002DGDATA003DGDATA101DGDATA102DGDATA103Now, make the simple…SQL ALTER DISKGROUP DGDATA ADDFAILGROUP FGAUXDISKORCL:DGDATA101 name DGDATA101 FORCE,ORCL:DGDATA102 name DGDATA102 FORCE,ORCL:DGDATA103 name DGDATA103 FORCE;Diskgroup altered.SQL ALTER DISKGROUP DGDATA rebalance power 8;Diskgroup altered.While waiting the reball, let’s see the disks in DG:SQL select * from v$asm_operation where group_number(select group_number from v$asm_diskgroup where nameDGDATA);GROUP_NUMBER OPERA STAT POWER ACTUAL SOFAR EST_WORK EST_RATE EST_MINUTES ERROR_CODE------------ ----- ---- ---------- ---------- ---------- ---------- ---------- ----------- --------------------------------------------3 REBAL WAIT 8SQL select name,failgroup,state from v$asm_disk a where group_number(select group_number from v$asm_diskgroup where nameDGDATA);NAME FAILGROUP STATE------------------------------ ------------------------------ --------_DROPPED_0000_DGDATA FGAUX FORCING_DROPPED_0001_DGDATA FGAUX FORCING_DROPPED_0002_DGDATA FGAUX FORCINGDGDATA101 FGAUX NORMALDGDATA102 FGAUX NORMALDGDATA103 FGAUX NORMALDGDATA001 FGMAIN NORMALDGDATA002 FGMAIN NORMALDGDATA003 FGMAIN NORMALAnd, when the rebalance end, the situation will be OK:SQL select * from v$asm_operation where group_number(select group_number from v$asm_diskgroup where nameDGDATA);GROUP_NUMBER OPERA STAT POWER ACTUAL SOFAR EST_WORK EST_RATE EST_MINUTES ERROR_CODE------------ ----- ---- ---------- ---------- ---------- ---------- ---------- ----------- --------------------------------------------3 REBAL RUN 8 8 629 19087 10143 1SQL select * from v$asm_operation where group_number(select group_number from v$asm_diskgroup where nameDGDATA);no rows selectedSQL select name,failgroup,state from v$asm_disk a where group_number(select group_number from v$asm_diskgroup where nameDGDATA);NAME FAILGROUP STATE------------------------------ ------------------------------ --------DGDATA101 FGAUX NORMALDGDATA102 FGAUX NORMALDGDATA103 FGAUX NORMALDGDATA001 FGMAIN NORMALDGDATA002 FGMAIN NORMALDGDATA003 FGMAIN NORMALOK? Easy!Matheus.