To use iSCSI storage on the server, one or more iSCSI LUs (LUs) must be defined. iSCSI LUs are blocks of SCSI storage that are accessed through iSCSI targets. iSCSI targets can be found through an iSNS database or through a target portal. After an iSCSI target has been found, an Initiator running on a Windows server can access the LU as a “local disk” through its target. Security mechanisms can be used to prevent unauthorized access to iSCSI targets.
On the server, iSCSI LUs are just regular files residing on a file system. As a result, iSCSI benefits from file system management functions provided by the server, such as NVRAM logging, snapshots, and quotas.
The contents of the iSCSI LUs are managed on the Windows server. Where the server views the LUs as files containing raw data, Windows views each iSCSI target as a logical disk, and manages it as a file system volume (typically using NTFS). As a result, individual files inside of the iSCSI LUs can only be accessed from the Windows server. Server services, such as snapshots, only operate on entire NTFS volumes and not on individual files.
