1. Storage Networking

2. Storage Trends Storage grows 20-150%/year, gets more complicated It’s necessary to pool storage for flexibility Intelligent storage is necessary to reduce administrative costs – simplify and automate management Continuous availability is required

3. RAID Consolidate multiple physical disks into a logical grouping Designed for fault tolerance and performance improvement Can be implemented in H/W or S/W Several RAID levels exist

4. RAID RAID 0 – Striping RAID 1 – Mirrored Volumes RAID0+1 – Mirror of stripes RAID 3 – Byte-level striping with Parity disk RAID 4 – Block-level striping with Parity disk RAID 5 – Striping with distributed Parity RAID1+0-Stripe of mirrors RAID 6 – Double striped to support 2 drive failures

5. Software RAID Volume Management performed by the server O/S Parity computation performed by the server – increased overhead RAID performance depends on the server performance and CPU load For simple environments with lower performance and availability environments

6. Hardware RAID Volume Management performed by RAID controller Parity computation performed by the RAID controller – decreases server overhead Dedicated cache memory improves server performance

7. DAS SCSI protocol Block-level access File system is on the server

8. NAS IP Network Clients Servers File Protocol: SMB/CIFS, NFS, etc. File-level access to the outside; block-level to the storage subsystem File system is on the NAS device

9. SAN Servers SCSI over Fibre Channel Storage Area Network Block-level access File system is on the server

10. iSCSI An alternative technology – allows SAN utilize TCP/IP for block-level data transfer Transport for SCSI commands Existing networks (routers/switches) can be utilized – no need for special equipment

11. Distributed File Systems SMB/CIFS; Samba (Windows-based systems) NFS (Unix-based) AFS (Unix) AFP (MAC) NCP (Netware)