CCDP SAN Design Considerations - Study Notes - Part 1

    SAN Design Considerations - Study Notes - Part 1


    Main Concepts


    DAS - Direct Attached Storage


    NAS - Network Attached Storage (access via NFS, CIFS)


    SAN - Storage Area Network (scsi technologies and fibre channel)




    HBA - Host Bus Adapter








    Cisco Storage Virtualization


    - Available logical space for data storage.


    - The SAN system handles the process of mappig to an actual physical device.


    - MDS 9000 family ==> VSANs capable


    - Trunking between VLANs ==> ISL and Enhanced ISL


    Inter-VSAN Routing


    - IVR is fabric routing


    - Sharing of centralized storage services across VSANs


    - Fabric Shortest Path First


    - Topology database


    - Dynamic Incremental SPF


    - Associates a cost with each link




    - Logical grouping of fabric devices within SAN or VSAN


    - Soft Zoning (using DNS) or Hard Zoning (equipment built in).



    FICON - Technology


    - Fiber connectiviy invented by IBM


    - Connects mainframes to SAN


    - Cisco supports FICON and FCP (Fibre Channel Protocol).



    SANTap - Technology


    - Protocol that allows third party storage application to be integrated into the SAN.


    - Replicates the data simultanously.


    Design Concerns


    - Port density.


    - Topology


    - Oversubscription


    - Traffic Management ==> different performance requirements should be handled using techniques


    - Fault Isoltation ==> using VSAN


    - Convergence and Stability



    SAN Design


    - Collapse core.


    - Dual Fabric collapse core


    SAN Extension


    - Remote connectivity between different SAN networks using protocols like FCIP and iSCSI.


    - FCIP: fiber channel over IP ==> any distance


    - iSCSI: SCSI over IP


    - Several enhancements: data compression and write acceleration