Hitachi Digital Services Interview Questions, Process, and Tips

SAN stands for Storage Area Network. It is a high-speed network that connects servers and storage devices.

• SAN is a dedicated network that allows multiple servers to access shared storage resources.

• It provides centralized storage management and allows for scalability and flexibility.

• SANs use protocols like Fibre Channel or iSCSI to connect servers and storage devices.

• SANs can be used for various purposes like data backu...read more

NAS stands for Network Attached Storage. It is a file-level storage device that provides centralized data storage and access over a computer network.

• NAS is a storage device that connects to a network and allows multiple users to access and share files.

• It provides file-level access, meaning users can access individual files and folders stored on the NAS.

• NAS devices often have their own operating system and can offer add...read more

Multipathing is a technique used in storage systems to provide redundancy and load balancing by using multiple paths between servers and storage devices.

• Multipathing improves storage system performance and availability.

• It allows for load balancing by distributing I/O traffic across multiple paths.

• Redundancy is achieved by having multiple paths in case one fails.

• Multipathing can be implemented at the hardware or softwar...read more

There are three types of topologies in SAN: point-to-point, arbitrated loop, and switched fabric.

• Point-to-point topology connects two devices directly.

• Arbitrated loop topology connects devices in a loop, where each device has a unique address.

• Switched fabric topology connects devices through a central switch, allowing multiple simultaneous connections.

• Examples: Fibre Channel (FC) and Internet Small Computer System Inte

There are three types of backup: full, incremental, and differential.

• Full backup: backs up all data and takes the longest time and uses the most storage space

• Incremental backup: backs up only the changes made since the last backup and is faster and uses less storage space than a full backup

• Differential backup: backs up all changes made since the last full backup and is faster than a full backup but uses more storage sp

Replication is the process of creating and maintaining a copy of data or information in another location.

• Replication ensures data availability and disaster recovery.

• It can be synchronous or asynchronous.

• Examples include database replication, file replication, and virtual machine replication.

Reduplication is the process of eliminating duplicate data in storage systems.

• Reduplication reduces storage space requirements and improves backup and recovery times.

• It works by identifying and removing identical data blocks and replacing them with pointers to a single copy.

• For example, if multiple users have the same file attachment in their emails, reduplication will store only one copy of the attachment and point to...read more