recovering from loss of an Online Redo Log File

Method 1:drop the damaged member and add a replacement member
1. drop the member
-- alter database drop logfile member '';
2. delete the file from disk physically
3. add a new member
-- alter database add logfile member '' to group ;


Method 2: clear the group (simple and devoid of any chance of error)
--This works only when no disk problem and the group has been archived
e.g
alter database clear logfile group 1;