Storage Area Networks -basics

Explanation
A buffer overflow occurs when a program or process tries to store more data in a temporary data storage area (buffer) than it was intended to hold. This can lead to the overwriting of adjacent memory locations, causing the program to crash or behave unexpectedly. It is a common vulnerability exploited by hackers to execute malicious code or gain unauthorized access to a system.

Explanation
The correct answer is "redundant array of independent disks" (RAID). RAID is a storage technology that involves storing the same data across multiple hard disks. It provides redundancy and improves data reliability and performance. By distributing data across different disks, RAID can enhance data access speed and protect against data loss in case of disk failure.

Explanation
A defragmenter is a utility that rearranges discontiguous files and free space on a computer so that files are stored in contiguous units and free space is consolidated in one contiguous block. This helps improve the performance and efficiency of the computer's file system by reducing file fragmentation and optimizing data storage.

Explanation
Disk striping is the process of dividing a body of data into blocks and spreading the data blocks across several partitions on several hard disks. This technique improves the overall performance of the system by allowing multiple disks to work in parallel, increasing the data transfer rate. It also provides fault tolerance as data is distributed across multiple disks, reducing the risk of data loss in case of disk failure. Therefore, disk striping is the correct answer.

Explanation
The correct answer is "U". In computer enclosures and rack cabinets, "U" is used as a standard unit of measure for designating height. Each "U" is equal to 1.75 inches. This unit helps in determining the size and spacing of equipment in these enclosures and cabinets.

Explanation
The Core-Edge SAN topology offers the highest level of redundancy and scalability. In this topology, there is a central core switch that connects to multiple edge switches. The core switch acts as a centralized point for data traffic, providing high availability and redundancy. The edge switches are connected to storage devices and servers, allowing for easy scalability by adding more edge switches as needed. This topology ensures that there are multiple paths for data to travel, minimizing the risk of single points of failure and providing high levels of redundancy and scalability.

Explanation
Nonvolatile memory refers to a type of solid-state memory that does not require a continuous power source and does not need its memory contents to be refreshed periodically. Unlike volatile memory, which loses its data when power is disconnected, nonvolatile memory retains its stored information even when power is turned off. This term encompasses various forms of solid-state memory, such as flash memory, that offer persistent storage capabilities.

Explanation
During Fabric merge, three processes occur: Zone set passing, principal switch negotiation, and Name server communication. Zone set passing involves the exchange of zone sets between switches to ensure that all switches in the fabric have the same zoning configuration. Principal switch negotiation determines the principal switch in the fabric, which is responsible for managing fabric-wide operations. Name server communication involves the exchange of information between switches regarding device names and addresses, allowing for proper communication and routing within the fabric. ISL trunking, on the other hand, is not directly related to fabric merge and therefore is not included in the processes that occur during this operation.

Explanation
Cache is used to reduce the effective time required to read data or write data to a lower speed memory or device. Cache is a small, fast memory that stores frequently accessed data and instructions closer to the CPU. When the CPU needs to access data, it first checks the cache, and if the data is found in the cache, it can be retrieved much faster than if it had to be fetched from the main memory or a lower speed device. This helps to improve overall system performance by reducing the latency associated with accessing slower memory or devices.

Explanation
In the distributed SCSI model, the SCSI target acts as the server, while the SCSI initiator acts as the client. The SCSI target is responsible for receiving and responding to commands from the SCSI initiator. It provides access to the storage resources and manages the data transfer between the initiator and the target. On the other hand, the SCSI initiator initiates the communication and sends commands to the target. It is responsible for initiating the data transfer and managing the overall communication process.