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Access "Tap into Windows' hidden resources to make it enterprise-worthy"

Published: 19 Oct 2012

@exb So, what exactly is a LUN? One of the most fundamental concepts of enterprise storage is the LUN, but it's often misunderstood. Put simply, a LUN is a chunk of storage on a SCSI-based network, including Fibre Channel and iSCSI SANs. The concept comes from SCSI, where target devices (originally an entire disk drive) are subdivided into a few logical units (originally partitions). Each unit is presented to a computer system ("initiator," in SCSI parlance) with a unique number--LUN actually stands for logical unit number. For example, let's say you had a 100GB SCSI drive alone on a SCSI bus configured as target device 0 (all SCSI addresses start at zero). If you partitioned that drive into five 20GB slices, you could address them as LUNs 0 through 4. The fourth slice would be target 0 LUN 3. Because RAID systems don't use disk partitions in the traditional sense, the LUN concept became cloudier. Some early RAID systems did away with LUNs altogether and simply addressed entire RAID sets as targets. Others allowed RAID sets to be sliced up and presented ... Access >>>

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