Storage Area Network (SAN) is common in large storage environments (and becoming more common). It can be used in multiple hosts attached to multiple storage arrays and it is more flexible than the HAS and NAS.
RAID uses multiple disk drives to provide reliability and performance via redundancy. RAID is arranged into six different levels i-e RAID-0 to RAID6 as shown in following diagram. Several improvements in disk-use techniques involve the use of multiple disks working cooperatively. Most common is Disk striping that uses a group of disks as one storage unit. RAID schemes improve performance and improve the reliability of the storage system by storing redundant data. Mirroring or shadowing keeps duplicate/copy of each disk. Block interleaved parity uses much less redundancy
Network interface card (NIC) is a computer circuit board that is installed in a computer to connect the computer to a network. Network interface cards provide a dedicated, full-time network connection for enterprise desktop PCs or servers.
Hosted Attached Storage (HAS) can be accessed through I/O ports talking to I/O busses. It uses SCSI and SCSI itself is a bus, up to 16 devices on one cable, SCSI initiator requests operation and SCSI targets perform tasks. Each target can have up to 8 logical units (disks attached to device controller
Virtual infrastructure is the basis for flexible, scalable and low-cost enterprise IT that has the capability to respond immediately to changing business needs. Virtual infrastructure decouples application workloads completely from underlying physical hardware. This allows applications to be deployed across a pool of physical servers to improve hardware utilization and management flexibility. The key building block of virtual infrastructure is a platform that abstracts the physical resources of an industry-standard server to provide a set of virtual resources to an application. VMware ESX Server provides that virtualization platform, and VMware VirtualCenter manages the virtual machines on physical servers running ESX Server. VMware VMotion permits the migration of applications running on virtual machines across this pool of virtual resources without service interruption.
Virtual machine is a virtualized Intel Xeon processor–based server environment on which a guest operating system and associated application software can run. Multiple virtual machines can operate on the same host machine concurrently.
Hosted Attached Storage (HAS) can be accessed through I/O ports talking to I/O busses. It uses SCSI and SCSI itself is a bus, up to 16 devices on one cable, SCSI initiator requests operation and SCSI targets perform tasks. Each target can have up to 8 logical units (disks attached to device controller
Virtual infrastructure is the basis for flexible, scalable and low-cost enterprise IT that has the capability to respond immediately to changing business needs. Virtual infrastructure decouples application workloads completely from underlying physical hardware. This allows applications to be deployed across a pool of physical servers to improve hardware utilization and management flexibility. The key building block of virtual infrastructure is a platform that abstracts the physical resources of an industry-standard server to provide a set of virtual resources to an application. VMware ESX Server provides that virtualization platform, and VMware VirtualCenter manages the virtual machines on physical servers running ESX Server. VMware VMotion permits the migration of applications running on virtual machines across this pool of virtual resources without service interruption.
Virtual machine is a virtualized Intel Xeon processor–based server environment on which a guest operating system and associated application software can run. Multiple virtual machines can operate on the same host machine concurrently.