A systems administrator is configuring new storage for a high availability server. Which of the following RAID configurations can still function it half its disks are lost?

RAID 1 mirrors data identically across two drives, meaning the array continues to function if either one of the two disks fails. Because the array consists of only two drives, losing one constitutes losing exactly half the disks, satisfying the requirement. No other standard RAID level guarantees survival of half its total disks regardless of array size.

RAID 3 uses byte-level striping with a single dedicated parity drive and can only tolerate the loss of one disk regardless of total disk count, which is far less than half in any practical deployment.

RAID 5 uses distributed parity across a minimum of three drives and can only tolerate a single disk failure; losing half of a RAID 5 array would result in data loss.

RAID 6 uses double distributed parity and can survive exactly two simultaneous disk failures regardless of array size, meaning it cannot survive losing half its disks in any array larger than four drives.