Link aggregation is a technique that combines multiple physical network links into one logical link with higher bandwidth and redundancy. It can take advantage of all the available bandwidth of the NICs (Network Interface Cards) on the server and provide load balancing and failover capabilities for network traffic. Verified Reference: [Link aggregation], [NIC]

Explanation
The most efficient subnet mask for a point-to-point heartbeat connection between two servers using IP addressing is /30. A /30 subnet mask has 255.255.255.252 as its decimal representation and
11111111.11111111.11111111.11111100 as its binary representation. This means that there are only two bits available for the host portion of the IP address, which allows for four possible combinations: 00, 01, 10, and
11. However, the first and the last combinations are reserved for the network address and the broadcast address, respectively. Therefore, only two IP addresses are usable for the point-to-point connection, which is the minimum required for such a link. A /30 subnet mask is also known as a point-to-point prefix because it is commonly used for point-to-point links between routers or servers1.
A /28 subnet mask has 255.255.255.240 as its decimal representation and
11111111.11111111.11111111.11110000 as its binary representation. This means that there are four bits available for the host portion of the IP address, which allows for 16 possible combinations. However, two of them are reserved for the network address and the broadcast address, respectively. Therefore, 14 IP addresses are usable for the subnet, which is more than needed for a point-to-point connection and would result in wasted addresses.
A /29 subnet mask has 255.255.255.248 as its decimal representation and
11111111.11111111.11111111.11111000 as its binary representation. This means that there are three bits available for the host portion of the IP address, which allows for eight possible combinations. However, two of them are reserved for the network address and the broadcast address, respectively. Therefore, six IP addresses are usable for the subnet, which is still more than needed for a point-to-point connection and would result in wasted addresses.
A /32 subnet mask has 255.255.255.255 as its decimal representation and
11111111.11111111.11111111.11111111 as its binary representation. This means that there are no bits available for the host portion of the IP address, which allows for only one possible combination: all ones.
Therefore, only one IP address is usable for the subnet, which is not enough for a point-to-point connection and would result in an invalid configuration.
Therefore, a /30 subnet mask is the most efficient choice for a point-to-point heartbeat connection between two servers using IP addressing because it provides exactly two usable IP addresses without wasting any addresses or creating any conflicts1.

The RAID level that provides the highest possible capacity for a storage array is RAID 0. RAID 0 is a type of RAID level that provides performance enhancement by using striping. Striping means dividing data into blocks and distributing them across multiple disks to increase speed and capacity. RAID 0 does not provide any fault tolerance or redundancy, as it does not use any parity or mirroring techniques. RAID 0 uses all of the available disk space for data storage, without losing any space for overhead. Therefore, RAID 0 provides the highest possible capacity for a storage array, but also has the highest risk of data loss.