SCSI Drives Chapter 13 Release 22/10/2010powered by dj

Slide 2 of 51Chapter 13 Objectives - I  List the advantages of SCSI  List the different SCSI interfaces  Identify the SCSI variations  List the different types of SCSI signals  Use the SCSI ID Release 22/10/2010powered by dj

Slide 3 of 51Chapter 13 Objectives - II  Work with SCSI connectors  Use the different SCSI cables  Work with SCSI drives  Install SCSI drives  Troubleshoot the SCSI drive Release 22/10/2010powered by dj

Slide 4 of 51Chapter 13 Advantages of SCSI - I  Data transmission speeds reach about 320 MB per second between the system and the device  Allows to attach 15 devices to a single SCSI port  SCSI controller boosts the signals and enables the devices to be connected at a distance of about 25 meters from the system Release 22/10/2010powered by dj

Slide 5 of 51Chapter 13 Advantages of SCSI - II  Reduces the processing load on the microprocessor, as they have a micro- controller built into the device  Communication problems between the system and SCSI device are reduced as the ends of the SCSI have terminators Release 22/10/2010powered by dj

Slide 6 of 51Chapter 13 Types of SCSI Interface and show P-3 of CBT  SCSI – 1 - Uses an 8-bit parallel bus to transfer data at a maximum speed of 5 MB per second. Can connect up to 8 devices with a cable length of 6 meters and uses passive terminators  SCSI – 2 - Uses a 16-bit bus to transfer data at a maximum speed of 20 MB per second. Can connect up to 8 devices and cable length of 3 meters. Uses 50 pin connector, command queuing feature and active terminator  SCSI – 3 - Uses a 16-bit bus to transfer data at a maximum speed of 40 MB per second. Can connect up to 16 devices and cable length is 3 meter. Uses active terminators Release 22/10/2010powered by dj

Slide 7 of 51Chapter 13 Question for GD Time Limit – 2 Mins  What are the different types of SCSI? Release 22/10/2010powered by dj Sl.Types of SCSI

Slide 8 of 51Chapter 13 SCSI Variations - I  Narrow SCSI – Transmits data over an 8-bit bus. Uses 50 pin connector cable known as A cable  Wide SCSI – Transmits data over a 16-bit bus. Uses 68 pin connector cable known as P cable  Fast SCSI – Transfers the data at the speed of 10 MB per second using the narrow SCSI  Wide Ultra – Transmits data at a speed of 20 MB per second for the narrow SCSI Release 22/10/2010powered by dj

Slide 9 of 51Chapter 13 SCSI Variations - II  iSCSI - (Internet SCSI) is a TCP/IP based protocol. It is used to establish and manage the connections between IP based storage devices, hosts and clients. iSCSI has almost same command set as basic SCSI which helps in preserving the basic SCSI standard.  Serial SCSI - The Serial SCSI performs the data transfer through serial communication. SSA (Serial Storage Architecture), Fibre channel, FireWire and SAS (Serial Attached SCSI) are the four versions of Serial SCSI. Release 22/10/2010powered by dj

Slide 10 of 51Chapter 13 Question for GD Time Limit – 2 Mins  What is the difference between narrow and wide SCSI? Release 22/10/2010powered by dj

Slide 11 of 51Chapter 13 SCSI Variations - III  SCSI Drive speeds – Available at speeds of 10,000 rpm to 15,000 rpm  Universal hard drive – Easy to upgrade the server hard drives and supports S.M.A.R.T feature  Serial Attached SCSI (SAS) – Allows much higher speed data transfer (6 Gb/s) than previously available and is backward compatible with SATA. Uses SCSI commands for interacting with SAS devices Release 22/10/2010powered by dj

Slide 12 of 51Chapter 13 Question for GD Time Limit – 5 Mins  What are the different SCSI variations? Release 22/10/2010powered by dj Sl.SCSI Variations

Slide 13 of 51Chapter 13 Types of SCSI Bus Signaling - I  Single-Ended (SE) – Transmits a positive voltage through a signal line to the receiver. Maximum cable length is 6 meter  High-Voltage Differential (HVD) – Reduces problems of bouncing signals, signal interference problems, noise and crosstalk. Enables cable length up to 25 meters. It is very costly Release 22/10/2010powered by dj

Slide 14 of 51Chapter 13 Question for GD Time Limit – 2 Mins  What is the difference between SE and HVD bus signaling? Release 22/10/2010powered by dj

Slide 15 of 51Chapter 13 Types of SCSI Signaling - II  Low-Voltage Differential (LVD) – Signals are transmitted using the difference in the voltage between the two wires. SCSI device adapter has a small transceiver built into it which boosts signal. Uses 3.3 voltage to represent logical 1 or 0  Low-Voltage Differential/ Single- Ended Multi- mode (LVD/SE) – Compatible with LVD and SE signaling. However if there is a device that uses SE signaling on SCSI bus, then this will be set to use SE signaling Release 22/10/2010powered by dj

Slide 16 of 51Chapter 13 Question for GD Time Limit – 4 Mins  What are different SCSI bus signaling? Release 22/10/2010powered by dj Sl.SCSI Signaling

Slide 17 of 51Chapter 13 Working with SCSI Identification (ID) - I  Jumper Block/ DIP Switch Settings – SCSI identification is set using software available with SCSI device, using the jumpers or switches on the SCSI device  Resolving Id Conflicts – SCSI identification specifies the priority in which the device has access to the bus. Host SCSI controller on the system is generally given the highest SCSI priority 7 to ensure that it gets first access to system resources. SCSI hard drives are factory set to have ID 0 Release 22/10/2010powered by dj

Slide 18 of 51Chapter 13 Working with SCSI Identification (ID) -II Release 22/10/2010powered by dj

Slide 19 of 51Chapter 13 Practical  Perform the activity mentioned in Lab no. 1 in the text book: To set the SCSI ID using switches. Release 22/10/2010powered by dj

Slide 20 of 51Chapter 13 Working with SCSI Connectors  Internal Connectors – Located on SCSI devices such as hard disks and CD drives that are installed inside the system case  External Connectors – Located on the SCSI adapters and the SCSI devices such as printers, scanners and external tape drives Release 22/10/2010powered by dj

Slide 21 of 51Chapter 13 Question for GD Time Limit – 2 Mins  Which type of connector is used for Ultra3 320 SCSI drive? Release 22/10/2010powered by dj

Slide 22 of 51Chapter 13 Using SCSI Cables  Type Internal SCSI Cable – Flat ribbon cable External SCSI Cables – Thick round cable Release 22/10/2010powered by dj Internal SCSI Cable External SCSI Cable

Slide 23 of 51Chapter 13 Practical Activity Time Limit – 4 Mins  Show different internal and external SCSI cables to students Release 22/10/2010powered by dj

Slide 24 of 51Chapter 13 Termination Requirement - I  SCSI devices use passive and active terminators.  Some devices also have the passive terminator built into them or have jumpers to activate the terminator.  SCSI bus requires two terminators one at either end of the SCSI bus.  However, you must not attach a terminator directly on the host controller. Release 22/10/2010powered by dj

Slide 25 of 51Chapter 13 Termination Requirement - II  Terminators are powered from the term power line on the SCSI bus.  Term power can come from any device on the bus, and is provided by either the host, a drive on the bus, the backplane, or any combination thereof.  Term power is provided through a diode and fuse and allows for a term power range of 4.0 to 5.25 volts Release 22/10/2010powered by dj

Slide 26 of 51Chapter 13 Types of Terminators - I  Internal - Some SCSI drives (pre-LVD) had passive terminators installed in the drive, and could be enabled/disabled by setting a jumper or inserted/removed from a socket. Drives with LVD interface do not have internal termination.  External - In-line (also called ‘feed-through’) terminators connect in series with a SCSI device. Close-ended terminators plug into a bus connector or may be crimped on the cable. Release 22/10/2010powered by dj

Slide 27 of 51Chapter 13 Types of Terminators - II  Passive Terminator – Use a resistor to terminate the SCSI signals and if the distance between the last device on the SCSI chain and the SCSI controller is less than 1 meter  Active Terminator – Use a resistor and a voltage regulator and if the distance between the last device on the SCSI chain and the SCSI controller is more than 1 meter Release 22/10/2010powered by dj

Slide 28 of 51Chapter 13 Passive and Active Terminator Release 22/10/2010powered by dj ActivePassive

Slide 29 of 51Chapter 13 Question for GD Time Limit – 2 Mins  What is termination? List the different types of terminators. Release 22/10/2010powered by dj Sl.Types of Terminator

Slide 30 of 51Chapter 13 RAID - I  Redundant Array of Inexpensive Disks (RAID) is a collection of hard disks that appear to the system as a single disk RAID Level 0 - Data is broken into blocks RAID Level 1 – total disk space available is half of total capacity of disks RAID Level 4 - Data are broken up into blocks of small size and distributed on various disks and parity blocks are stored in a dedicated disk. Release 22/10/2010powered by dj

Slide 31 of 51Chapter 13 Question for GD Time Limit – 3 Mins  What is RAID and what is it’s advantages? Release 22/10/2010powered by dj

Slide 32 of 51Chapter 13 RAID - 5  Frequently used method to RAID hard disks.  Data as well as the parity information is stored on multiple disks.  If one drive fails, the failed disk can be recreated after it is replaced.  It is preferable to use hard disks of same storage capacity to implement RAID Level 5.  Available disk space is the sum of the size of all disks minus the size of one disk. Release 22/10/2010powered by dj

Slide 33 of 51Chapter 13 RAID - 5  RAID Level 5 requires a minimum of 3 disks to be implemented.  If two hard drives crash simultaneously then data cannot be retrieved. Release 22/10/2010powered by dj

Slide 34 of 51Chapter 13 Question for GDTime Limit – 3 Mins  What is RAID5 and why it’s mostly used in organizations? Release 22/10/2010powered by dj

Slide 35 of 51Chapter 13 RAID - II RAID Level 6 - It is similar to RAID 5 but uses an additional parity block. It employs two parity blocks for additional data protection. If two hard drives crash simultaneously, data can still be retrieved. Requires a minimum of 4 disks to be implemented. Release 22/10/2010powered by dj

Slide 36 of 51Chapter 13 RAID - III  RAID It implements both striping and mirroring data among disks. Two RAID 0 stripes are created and a RAID 1 mirror is created over those two disks. RAID level requires a minimum of 4 drives to be implemented.  RAID 10 - This uses disk mirroring and stripping without the use of parity which results in better data security and performance. Release 22/10/2010powered by dj

Slide 37 of 51Chapter 13 RAID - IV RAID 50 – RAID level 50 is a combination of RAID level 5 and RAID level 0. Combines striping of RAID 0 with distributed parity of RAID 5. Requires at least six drives. It is implementing across two RAID 5 arrays. It divides the data into smaller blocks and stripes the blocks into each RAID 5 raid set. Release 22/10/2010powered by dj

Slide 38 of 51Chapter 13 Group Activity Time Limit – 5 Mins  Draw a window pane on different RAID levels. Release 22/10/2010powered by dj

Slide 39 of 51Chapter 13 Hot Swap Drives Release 22/10/2010powered by dj

Slide 40 of 51Chapter 13 Installing SCSI Drives and show from CBT - I  Installing the Host Adapter – Given the highest priority over SCSI bus so that it can serve other devices properly  Installing the Internal SCSI Device – Connects to the host adapter bus using the SCSI cable  Terminate the ends of SCSI cable. LVD drives do not have any provision for onboard termination; therefore, termination for LVD drives must come from another device or from an external terminator Release 22/10/2010powered by dj

Slide 41 of 51Chapter 13 Installing SCSI Drives and show from CBT - II  Configure Terminator Power - Active terminators must receive power from some source.  The default configuration results in the drive not supplying termination power to the bus.  Usually, the host adapter provides term power. Check the user's manual for your host adapter. Release 22/10/2010powered by dj

Slide 42 of 51Chapter 13 Practical  Perform the activity mentioned in Lab no. 2 in the text book: To install a SCSI host adapter and an internal SCSI device. Click on the image to run the video. Release 22/10/2010powered by dj

Slide 43 of 51Chapter 13 SCSI HD Detect Video Release 22/10/2010powered by dj Click on the image to run the video.

Slide 44 of 51Chapter 13 Troubleshooting - I  Problem with the SCSI Daisy-Chain – oIn a daisy chain any problem with any one device may cause all the devices to malfunction oCheck that the power supply is switched on for all the devices oCheck that the cables in the daisy-chain are properly connected and not loose oCheck that both ends of the SCSI daisy-chain are terminated oCheck that the SCSI ID is not repeated for two or more devices oDisconnect all the devices and reconnect them one by one oReinstall the device drivers Release 22/10/2010powered by dj

Slide 45 of 51Chapter 13 Troubleshooting - II  The Connected Device is not Functioning Properly - oCheck if the devices are connected properly oEnsure that the terminators are secured properly at the ends of the SCSI daisy-chain oChange the SCSI ID of the device oReinstall the device driver Release 22/10/2010powered by dj

Slide 46 of 51Chapter 13 Summary I  Small Computer Systems Interface (SCSI) enables you to attach peripherals to the system  SCSI consists of controller, cables and the device  Advantages of SCSI: Faster transfer of data Attach multiple devices Devices can be placed at a distance from the system Reduces load on microprocessor Reduces reflection of data signals Release 22/10/2010powered by dj

Slide 47 of 51Chapter 13 Summary II  SCSI standards specify the features of SCSI devices  SCSI bus signaling specifies the method used by the SCSI devices to communicate with each other  Different SCSI signaling methods: Single-Ended Low-Voltage Differential High Voltage Differential Low-Voltage Differential / Single-Ended Multi-mode Release 22/10/2010powered by dj

Slide 48 of 51Chapter 13 Summary III  The SCSI ID specifies the priority of the SCSI device on the SCSI bus  SCSI connectors enable you to affix the SCSI cable to the SCSI adapter or the SCSI device  The SCSI terminator is used to terminate the SCSI daisy-chain Release 22/10/2010powered by dj

Slide 49 of 51Chapter 13 Summary IV  Active terminators have a resistor and also a voltage regulator  RAID is a collection of hard disks that appear to the system as a single disk  Hot swap drives enable you to connect and disconnect drives to the system without shutting down or restarting the system  Installing SCSI host adapter, internal and external SCSI drives Release 22/10/2010powered by dj

Slide 50 of 51Chapter 13 Explorative Work  Refer to Internet, reference books or magazine to get the information.  Do not copy the information provided in this text book.  Consult your faculty for further guidance. Release 22/10/2010powered by dj SCSI Drive Sl.MakeSCSI/SAS Type of Interface Speed (rpm)CapacityDTRConnector Hot swappable (Y/N) Year of Release

Slide 51 of 51Chapter 13 Mind Map  Draw a mind map to summarize this chapter Release 22/10/2010powered by dj