[Storage]

1. [Storage] Version 1.2

2. Course Outline • Introduction to Network Storage • RAID Technologies • Storage Essentials • Basic Terminologies and Concepts • Hard Drive Interface Technologies • SAN Technologies • Fiber Channel Technology • iSCSI Technology • D-Link SAN (Storage Area Network) • D-Link Products for Storage Area Network • Market Analysis for D-Link SAM Products • D-Link SAN Implementation • SAN Product Features Overview • Volume Management • Device Management • iSCSI Features • Volume and RAID Support • D-Link NAS (Network Attached Storage) • D-Link Products for Network Attached Storage • Market Analysis for D-Link NAS Products • NAS Product Features Overview • Managing the Device • User and Group Management • Appliance Servers • Network Features • USB Port Applications • Applications and Solutions for Network Storage • NAS Applications • SAN Applications

3. Introduction to Network Storage

4. Introduction to Network Storage After this section, you should gain more knowledge of the following: Types of current storage solutions for computerized devices Characteristics of DAS and the challenges of using it Characteristics of NAS and the benefits/advantages that it offers Characteristics of SAN and the benefits/advantages that it offers Differences among each storage solution Introduction to Network Storage

5. Evolutions of Storage Technology 1963 1982 • 1940s – Data was mostly stored on punched card and punched paper tape. • 1951 – First computer to use magnetic tape for storage. • 1956 – IBM introduced the first commercial hard disk drive known as RAMAC (Random Access Method of Accounting and Control). • 1962 – The laser diode was invented by IBM which became the fundamental technology for read-write optical storage devices. • 1963 – IBM introduced the first storage unit with removable disks. This became an end for punched-cards era. • 1970 – Portable storage was born with the invention of the floppy disk. • 1978 – The first patent for RAID technology was filed. • 1981 – The Intelligent interface for disk drive “SASI” was developed by Shugart Associates and NCR Corporation. This interface is the predecessor to SCSI interface. • 1982 – SCSI interface was born and developed based on its predecessor, SASI. • 1984 – Compaq and Western Digital Co. produced ST506 controller that was able to be mounted on the hard disk drive and connected to the PC using a 40-pin cable. • Storage Evolutions • Introduction to Network Storage 1940 1951 1956 1962 1970 1978 1981 1984 Page is Animated

6. Evolutions of Storage Technology (cont’d) 1986 2001 • 1985 – First IDE drive was built by integrating ST506 controller in the hard disk drive. • 1986 – SCI specification was defined in a ANSI standard X3.131-1986. • 1994 – SCSI-2 became an ANSI standard X3.131-1994 and the IDE standard was approved by the ANSI under the name ANSI X3.221-1994. • 1996 – The ATA-2 interface that complied with the ANSI X3.279-1996 standard was the AT Attachment Interface with Extensions, and the ATA-2 interface that complied with the ANSI X3.279-1996 standard was the AT Attachment Interface with Extensions. • 1998 – The ATA/ATAPI-4 interface that complied with the ANSO NCITS 317-1998 was the AT Attachment Interface with Packet Interface Extension. • 2000 – The ATA/ATAPI-5 interface that complied with the ANSI NCITS 340-2000 was the AT Attachment Interface with Packet Interface-5. • 2000 – The Serial ATA 1.0 Working Group was established to specify Serial ATA for desktop applications. • 2001 – Serial ATA 1.0 was released in August of 2001 (with subsequent revisions 1.0a and 1.1) which provided significant improvement over parallel ATA. • 2003 – Hitachi bought IBM Data Storage Division. • Storage Evolutions • Introduction to Network Storage 1985 1994 1996 1998 2000 2003 Page is Animated

7. Types of Storage Solution • Internal Storage • Memory (DDR) • IDE ATA Hard Disk / Optical Compact Disk • SCSI Hard Disk • SATA Hard Disk • External Storage • Direct Attached Storage (DAS) • Network Storage • Network Attached Storage (NAS) • Storage Area Network (SAN) • USB Storage Enclosure • Firewire 1394 Storage Enclosure • Slim Disk Memory • Storage Solutions • Introduction to Network Storage

8. Storage Solutions • Introduction to Network Storage • A storage system directly attached to a client (commonly to a computer or server), without a storage network in between. • Common example of DAS would be a storage enclosure externally attached to a server, where clients in the network must access the server in order to connect to the storage device. Direct Attached Storage (DAS) Oracle Database Server Host Bus Adapter DAS #1 Local Area Network File Server DAS #2 Active Directory Server DAS #3 Client Network Application Server DAS #4

9. Challenges of DAS • Difficulty managing servers and storage with slow backup causing heavy LAN congestion • Limited number of drives supported • Limitation on storage size • Inability to share storage across multiple servers • Time-consuming and complex backup and management • Need for storage down time (off-line) when installing additional drives • Storage Solutions • Introduction to Network Storage

10. Storage Solutions • Introduction to Network Storage • Simplify storage management by separating the data from application server. Solution for DAS DAS  Network Storage

11. Why Do We Need Network Storage? • Volume of data keeps growing exponentially • Redundancy and backup necessity • Data availability and accessibility • Storage consolidation for centralized management* • Increase reliability and better performance (speed) • Storage virtualization* • Overall cost reduction • Data Protection * Unique characteristics possessed by SAN only. • Storage Solutions • Introduction to Network Storage

12. Storage Solutions • Introduction to Network Storage • NAS is a file-level computer data storage device connected to a computer network providing data access to heterogeneous network clients. • A NAS unit is essentially a self-contained computer connected to a network, with the sole purpose of supplying file-based data storage services to other devices on the network. • NAS are usually accessed by workstations and servers through a network protocol such as TCP/IP and applications such as Network File System (NFS) or Common Internet File System (CIFS) / Server Message Block (SMB) for file access. Network Attached Storage (NAS) Overview Public Local Area Network File Server Application Server NAS Client

13. Storage Solutions • Introduction to Network Storage • A high performance storage network that transfers block-level data between servers and storage devices, separate from the local area network (LAN) traffic. • In a SAN environment, storage devices, such as DAS, RAID arrays, or tape libraries are connected to servers using fiber channel or iSCSI. • Characteristics of SAN: • Virtualization • Storage Consolidation • Scalable • Block data transfer uses encapsulated SCSI Storage Area Network (SAN) Overview High performance private storage network File Server Public Local Area Network SAN Application Server Client

14. Differences of NAS and SAN • Storage Solutions • Introduction to Network Storage

15. Storage Solutions • Introduction to Network Storage Comparison for each of the Storage Solutions High performance private storage network File Server Public LAN SAN Appliance Application Server Client

16. Summary: Introduction to Network Storage • Clients can choose from three types of storage systems to keep their data on: Direct Attached Storage (DAS), Network Attached Storage (NAS), and Storage Area Network (SAN). • Direct Attached Storage (DAS) is the most commonly used data storage solution for end user level client devices (computers, servers). It attaches the storage enclosure directly to the client device. • Network Attached Storage (NAS) is mainly targeted for home and SMB users, and offers the benefits of network storage with ease of sharing files and centralized data storage over the IP network. • Storage Area Network (SAN) is mainly targeted for Server Farms or Special Applications, e.g. IP Surveillance, and offers high performance network storage solutions for data transfers over enterprise network, with benefits include virtualization, storage consolidation, etc. • D-Link supports data transfer over the iSCSI protocol for SAN devices. • Summary • Introduction to Network Storage

17. Questions and Answers: Introduction to Network Storage • What is the characteristic of Direct Attached Storage? • Storage is connected to the server without being separated with TCP/IP network • Storage consolidation capability • Data transfer using Network File System (NFS) protocol • Link multiple storage repositories to multiple clients and servers • What is the characteristic of D-Link Network Attached Storage? • Provide slow data access • Block data transfer along long distance is possible • Data transfer using CIFS/SMB protocol • Support server virtualization • What are the characteristics of D-Link Storage Area Network? (Choose Two) • File-level data transfer along long distance • Storage is connected directly to the server using iSCSI protocol • Block data transfer • Support storage virtualization and consolidation • Questions and Answers • Introduction to Network Storage

18. RAID Technologies

19. RAID Technologies After this section, you should gain more knowledge of the following: RAID mechanisms overview RAID types supported by D-Link network storage appliances Characteristics of each RAID type supported by D-Link as well as the advantages and disadvantages for each (RAID 0, RAID 1, RAID 5, RAID 10, and JBOD) RAID Technologies

20. RAID Technology Overview • Redundant Arrays of Independent Disks (RAID) is a data storage mechanism for dividing and/or replicating data over multiple hard drives, thus which may provide better performance, reliability, and/or larger data volume sizes. Depending on the type of RAID applied, different benefits can be achieved. • D-Link network storage supports several RAID technologies as described below: • Introduction to RAID • RAID Technologies

21. RAID 0 Technology Overview • Characteristics of RAID 0 • RAID 0 works by striping the data (Data-striping) across the hard drives • At least two hard drives must be provided • Improved performance (high speed data transfer) • No fault-tolerance • No error-checking • Advantages and disadvantages • RAID 0 • RAID Technologies

22. RAID 0 • RAID Technologies Illustration of RAID 0 Data 1 2 3 4 5 6 Primary Disk ✕ Disk-0 Disk-1 Disk 0 Network Storage 1 2 ✕ 3 4 Disk 1 5 6 If RAID 0 is in use and one of the disks in the array crashes, the rest of disks in the array will also not work. This will result is total data loss. Page is Animated

23. RAID 1 Technology Overview • Characteristics of RAID 1 • RAID 1 works by mirroring the data • At least two hard drives must be provided • Fault-tolerance • Advantages and disadvantages • RAID 1 • RAID Technologies

24. RAID 1 • RAID Technologies Illustration of RAID 1 If RAID 1 is in use and the primary disk crashes, the mirrored disk will automatically replace the primary disk. Disk-0 Disk-1 1 1 ✕ 2 2 Network Storage Primary Disk 3 3 4 4 Mirrored Disk 100% Redundancy!!! Page is Animated

25. RAID 5 Technology Overview • Characteristics of RAID 5 technology: • Striped set with distributed parity • Minimum three disks must be provided to implement RAID 5 • Offers data protection and increases throughput • Advantages and Disadvantages • RAID 5 • RAID Technologies

26. RAID 5 • RAID Technologies Illustration of RAID 5 Data to be written: 101110011010 Using RAID 5, if one of the disks in the array fails, data in the failed disk can be recovered Data is fully recovered!!! Disk-2 fails, data cannot be accessed!!! ✕ New Disk to replace the failed disk Disk-0 Disk-1 Disk-2 1 0 P=1 (1 XOR 0) 1 XOR 0 = 1 1 P=0 (1 XOR 1) 1 1 XOR 0 = 1 P=1 (1 XOR 0) 1 0 1 XOR 1 = 0 0 P=1 (0 XOR 1) 1 1 XOR 0 = 1 1 0 P=1 (1 XOR 0) 1 XOR 0 = 1 1 P=1 (1 XOR 0) 0 1 XOR 1 = 0 Rebuilt process started! Data can be rebuilt to the new disk using XOR calculations by recalculating the two bits retrieved from the existing drives P: parity Page is Animated

27. RAID 10 Technology Overview • Characteristics of RAID 10 technology: • RAID 10 provides mirroring and striping at the same time • Minimum four disks or even number of disks is required • Provides fault-tolerance and improves performance • Advantages and Disadvantages • RAID 10 • RAID Technologies

28. RAID 10 • RAID Technologies Illustration of RAID 10 RAID 0 - Stripe RAID 1 - Mirror RAID 1 - Mirror Disk-0 Disk-1 Disk-2 Disk-3 1 1 2 2 3 3 4 4 5 5 6 6 Very high reliability combined with high performance!!!

29. JBOD Technology Overview • Characteristics of JBOD (Just a Bunch Of Disks): • No Data redundancy, which means no fault-tolerance • Bigger array capacity • Two or more hard disks are required to create one logical drive • Advantages and Disadvantages • JBOD • RAID Technologies

30. JBOD • RAID Technologies • JBOD is usually known as concatenation where the total storage capacity equals to the sum of each separate disk. Illustration of JBOD Logically seen as one big storage Disk-1 Disk-0 1 65 2 67 … Total storage capacity (Σ) = capacity of Disk-0 + capacity of Disk-1 ……. 64

31. Summary for Each RAID Technology • D-Link Storage Area Network allows migration between RAID levels, but this is dependent on number of HDD drives available. • The performance of each RAID level may vary depending on the hardware platform used. • Summary for Each RAID Type • RAID Technologies

32. Summary: RAID Technologies • Redundant Array of Independent Disks (RAID) is a data storage mechanism that provides better performance and/or data reliability. • D-Link network storage appliances support RAID 0, RAID 1, RAID 10, RAID 5, RAID 6 and JBOD to offer greater performance and reliability for D-Link users. Which types of RAID supported is dependent on the models. • RAID 0 provides the best performance with the fastest data transfer speed by striping all the data to multiple disks. • RAID 1 provides data redundancy by mirroring/duplicating the data from one disk to another disk. • RAID 5 offers data protection and increases throughput by creating data parity and distributing it to all the provided disks. • RAID 6 offers data protection and increases throughput by creating data parity and distributing it to all the provided disks. Same as RAID 5, but with 2 parity disks. • RAID 10 combines both RAID 0 and RAID 1 at once, thus providing greater performance while also serving data redundancy to prevent single point of failure. • Just a Bunch of Disks (JBOD) is not a type of RAID mechanism and does not provide data redundancy. It is used for achieving greater storage capacity among all the hard disks, which may come in different sized capacity. • Summary • RAID Technologies

33. Questions and Answers: RAID Technologies • Which RAID level does not support fault-tolerance for the stored data? • RAID 0 • RAID 1 • RAID 10 • RAID 5 • JBOD • Which RAID technology supports the consolidation of all disks with different sizes thus enlarging the capacity of available storage spaces? • RAID 0 • RAID 5 • JBOD • RAID 10 • Questions and Answers • RAID Technologies

34. Storage Essentials

35. Storage Essentials After this section, you should gain more knowledge of the following: Basic terminologies commonly used to explain storage technology Different hard drive technologies and the characteristics of each Storage Essentials

36. Basic Terminologies • Block – A sequence of bytes or bits in which data is stored and retrieved on disk and tape devices. • Array – A set of physical disks grouped into one or more logical drives. • Logical drive - A set of actual physical disks that are grouped together and behave as if it were a single drive as seen by the user. • Volume – A set of blocks of storage that are organized and presented for use by the server. • Logical Unit Number (LUN) – number assigned to a logical unit. • It can be used to refer to an entire physical disk, or a subset of a larger physical disk or disk volume. The physical disk or disk volume could be an entire single disk drive, a partition (subset) of a single disk drive, or disk volume from a RAID controller comprising multiple disk drives aggregated together for larger capacity and redundancy. LUNs represent a logical abstraction between the physical disk device/volume and the applications. For example if you partition a disk drive into smaller pieces for your application or system needs (perhaps your server's operating system has a disk drive size limit) the sub-segments would share a common SCSI target ID address with each partition being a unique LUN. • In an iSCSI environment, LUNs are essentially numbered disk drives. An initiator negotiates with a target to establish connectivity to a LUN; the result is an iSCSI session that emulates a SCSI hard disk. Initiators treat iSCSI LUNs the same way as if they were a raw SCSI or IDE hard drive. For instance, rather than mounting remote directories as will be done in NFS or CIFS environments, iSCSI systems format and directly manage file systems on iSCSI LUNs. • In enterprise deployments, LUNs usually represent slices of large RAID disk arrays, often allocated one per client. iSCSI imposes no rules or restrictions on multiple computers sharing individual LUNs; shared access to a single underlying file system is instead left as a task for the operating system. • Basic Terminologies and Concepts • Storage Essentials

37. Basic Terminologies and Concepts • Storage Essentials • Definition of Spare • Spare is an drive (drive B) which is reserved for the purpose of substituting for another drive (drive A) in case of a failure on drive A. • Definition of Hot Spare • Hot spare is a drive which has been flagged for use if another drive in the array fails • Definition of Spare Count • Spare count is the number of drives to be kept available in case a drive which contains a volume (with data) fails. Spare Count When one of the active drives fails, the hot spare drive will replace the failed drive Active Drives Hot Spare Drive Spare Count = 1 Page is Animated

38. Hard Drive Interface Technologies • Storage Essentials • ATA (Advanced Technology Attachment) • Mostly used in desktops and notebooks • Consist of two standards: • PATA (Parallel ATA) • SATA (Serial ATA) • SCSI • Serial Attached SCSI (SAS) • Fiber Channel* Hard Drive Interface Technologies Overview * Fiber channel is now commonly used for SAN solutions, but seldom used for end user computers. Though there are Fiber Channel hard drives available in the market, they are hardly found these days.

39. Hard Drive Interface Technologies • Storage Essentials Why SATA? Serial ATA offers more features and better performance than parallel ATA Page is Animated

40. Hard Drive Interface Technologies • Storage Essentials • The Serial ATA (SATA) working group will deliver incremental specification releases over the next several years. These enhancements will enable the technology to support a variety of possible storage configurations. Evolution of SATA • Serial ATA II, Phase 2 • Second-generation speed grade for desktops and network storage systems (Targeted 300 MB/sec) • Improvements to address additional needs in higher-end network storage segments • Topology support for dual host active failover • Efficient connectivity to larger number of devices • Serial ATA II, Phase 1 • Improved use of SATA 1.0 technology in server and network storage • Backplane interconnect solution for racks of hot-swap drives • Complete enclosure management solution (Fan control, drive lights, temperature control, new device notifications, etc) • Performance improvement to address industry needs (firmware/ software, performance enhancements, including native queuing) • Serial ATA 1.0 • Primary inside-the-box storage connection to replace parallel ATA Page is Animated

41. Hard Drive Interface Technologies • Storage Essentials • SCSI (Small Computer System Interface) is a set of standards for physically connecting and transferring data between computers/ servers and peripheral devices. • SCSI is commonly used for hard disks and tape drives, but can also be connected to a wide range of other devices, including scanners and CD drives. SCSI Technology Overview

42. Summary: Storage Essentials • Hot spares are standby hard disk drives which are used as a backup to automatically replace a disk when a failure occurs. Spare count is the number of the hard disk drives provided as backup disks. • Currently, there are many hard drive technologies being provided in the market which evolves from time to time. The most well known technologies are SATA, SCSI, Serial Attached SCSI (SAS), and Fiber Channel. • SATA is the most commonly used technology today, especially at the end user level, e.g. computer device. • SCSI was commonly used for hard disks and tape drives, but can also be connected to a wide range of other devices, including scanners and CD drives. Currently, SCSI is widely used on servers and not on the end user client devices. • Summary • Storage Essentials

43. Questions and Answers: Storage Essentials • What is the benefit of providing a spare disk? • To enlarge the storage capacity when all disks have been used to store data. • Ensure reliability by designating the spare disk as a standby/backup disk which will be used in case of disk failure. • To serve as additional disk for use when scheduled downloading is configured. • To serve as part of a RAID when configured, for example, to save mirrored data for RAID 1. • Select the hard drive type(s) which offer the key advantages of full bandwidth to each connected device, hot plug capability, smaller connector, standardized connector placement and layout, simpler cabling, and longer cable length. (Choose all that apply) • SCSI • SATA • iSCSI • PATA • What are the benefits of using SATA hard disks when compared to IDE hard disks? (Choose all that apply) • Master/Slave selection • Smaller cable connector • Speed • Hot-pluggable • Questions and Answers • Storage Essentials

44. SAN Technologies

45. SAN Technologies After this section, you should gain more knowledge of the following: Technologies built for Storage Area Network Details about FC SAN technologies and the required components to implement it on the network Details about iSCSI technologies as well as its advantages and the required components to implement iSCSI on SAN SAN Technologies

46. Technologies lies behind the SAN • SAN Technologies • Technologies created for building a SAN are primarily based on either Fiber Channel or iSCSI technology. • The next few pages explain each of these technologies in greater detail. iSCSI Initiator TCP/IP Protocol iSCSI Target SAN Technologies Overview D-Link SAN Ethernet Switch Private Local Network SAN iSCSI Technology D-Link SAN Copper / Optical cabling for iSCSI connection

47. Fiber Channel Technology Overview • Fiber Channel (FC) is a channel/network standard defined by the Technical Committee T11, which is the committee within INCITS (InterNational Committee for Information Technology Standards) responsible for Fiber Channel Interfaces • FC network contains network features that provide the required connectivity, distance, and protocol multiplexing. • Advantages of Fiber Channel*: • Solutions leadership • Reliable • Fast data transfer providing gigabit bandwidth up to 4Gbps • Multiple topologies • Scalable • Congestion free • High Efficiency • Full suite of services * The information is taken from Fiber Channel Industry Association (http://www/fibrechannel.org) • Fiber Channel Technology • SAN Technologies

48. Fiber Channel Technology • SAN Technologies • Storage devices supporting Fiber Channel • Fiber Channel Switch (SAN fabric) • Fiber Channel Host Bus Adapter (HBA) • Cabling Basic Components of Fiber Channel SAN FC Host Bus Adapter FC Storage Media Public Local Area Network Fiber Channel Switch Private Fiber Channel SAN Optical cabling for fiber channel connection

49. iSCSI Technology Overview • Definition of iSCSI (Internet SCSI) • SCSI protocol which enables access to networked storage devices over a TCP/IP network (Ethernet network, WAN, Wireless network, etc) • Why iSCSI? – iSCSI Features • Error Handling • Error checking using CRC (Cyclic Redundancy Check) methodology • When iSCSI detects errors it will bring down the session (all TCP connections within the session) and restart it • Boot • Discovery • Advantages of iSCSI • Connectivity over long distances • Lower costs • Easier implementation and management • Built-in security • Hard Drive Interface Technologies • SAN Technologies

50. Hard Drive Interface Technologies • SAN Technologies • iSCSI is a better alternative to Fiber Channel SAN for the following reasons: • Built on stable and familiar standards providing easier implementation and management • Ethernet transmissions can travel over the global IP network and therefore have no practical distance limitation • Scalable • Creates a SAN with lower cost • Interoperability issue • Security issue Advantages of iSCSI over FC SAN Source : IDC 2006 Sept./Dec. According to IDC, iSCSI market grows with an explosive record of about 108.4% every year. According to IDC, by 2010, iSCSI products will share more than 21% of the storage market.