Hard Drive TechnologiesHard Drive Technologies

Joe CiceroJoe CiceroNortheast Wisconsin Technical CollegeNortheast Wisconsin Technical College

This Presentation Will Cover…This Presentation Will Cover…

Types of Hard DrivesTypes of Hard DrivesSATA, ATA, SCSI, etcSATA, ATA, SCSI, etc

Hard Drive PartsHard Drive PartsPlatter/s, Read/Write Head/s, Actuator Arm/s, Platter/s, Read/Write Head/s, Actuator Arm/s,

Actuator, Spindle, etc.Actuator, Spindle, etc.How A Hard Drive WorksHow A Hard Drive Works

Modifying Magnetic MediaModifying Magnetic MediaHard Drive MathHard Drive Math

Why 1000 = 1024Why 1000 = 1024

Continued…Continued…

Hard Drive ControllersHard Drive Controllers IDE, EIDE, SCSI, SATA, RAID, etcIDE, EIDE, SCSI, SATA, RAID, etc

Configuring Hard DrivesConfiguring Hard DrivesJumpers, Master, Slave, Cable Select, IDE / Jumpers, Master, Slave, Cable Select, IDE /

EIDE Cable capabilities, etc.EIDE Cable capabilities, etc.Partitioning A Hard DrivePartitioning A Hard Drive

Primary, Extended, Logical DrivesPrimary, Extended, Logical DrivesFormat of Hard DriveFormat of Hard Drive

FAT, NTFS, EXT3, etcFAT, NTFS, EXT3, etc

Continued…Continued…

Hard Drive MaintenanceHard Drive MaintenanceChkdsk, cleanmgr, defrag, limitations, etc.Chkdsk, cleanmgr, defrag, limitations, etc.

Types of Hard DrivesTypes of Hard Drives

Hard drives come in many different types. Hard drives come in many different types. Some of these are:Some of these are:ATAATA

ATA : Also known as IDE (Integrated Drive ATA : Also known as IDE (Integrated Drive Electronics) supports one or two hard drives per Electronics) supports one or two hard drives per cable, a 16-bit interface and PIO (Programmed cable, a 16-bit interface and PIO (Programmed Input/Output). Input/Output).

ATA Hard DriveATA Hard Drive

Types of Hard Drives Continued:Types of Hard Drives Continued:

SATASATASATA or S-ATA, an evolution of the ATA physical SATA or S-ATA, an evolution of the ATA physical

storage interface. Serial ATA is a serial link -- a storage interface. Serial ATA is a serial link -- a single cable with a minimum of four wires creates a single cable with a minimum of four wires creates a point-to-point connection between devices. point-to-point connection between devices. Transfer rates for Serial ATA begin at 150 MBps Transfer rates for Serial ATA begin at 150 MBps and SATA II 300MBps. and SATA II 300MBps.

One of the main design advantages of Serial ATA One of the main design advantages of Serial ATA is that the thinner serial cables facilitate more is that the thinner serial cables facilitate more efficient airflow inside a form factor and also allow efficient airflow inside a form factor and also allow for smaller chassis designs.for smaller chassis designs.

SATA Hard DriveSATA Hard Drive

Types of Hard Drives Continued:Types of Hard Drives Continued:

SCSISCSI This acronym is pronounced "scuzzy" and stands for Small This acronym is pronounced "scuzzy" and stands for Small

Computer Systems Interface. IDE and SATA are much more Computer Systems Interface. IDE and SATA are much more common and less expensive. common and less expensive.

The biggest difference between SCSI, ATA and SATA is that The biggest difference between SCSI, ATA and SATA is that while SCSI has a processor integrated into the controller, ATA while SCSI has a processor integrated into the controller, ATA and SATA make greater use of the system processor to serve and SATA make greater use of the system processor to serve that function.that function.

SCSI is more expensive and also more flexible and generally the SCSI is more expensive and also more flexible and generally the drive spins faster – but it should be noted that spinning faster drive spins faster – but it should be noted that spinning faster doesn’t necessarily make it work faster with the OS.doesn’t necessarily make it work faster with the OS.

With a single SCSI card you can have 15 or more devices With a single SCSI card you can have 15 or more devices whereas typically you are only allowed to have 4 devices with an whereas typically you are only allowed to have 4 devices with an ATA/IDE or SATA system. ATA/IDE or SATA system.

SCSI Hard DriveSCSI Hard Drive

Hard Drive PartsHard Drive Parts

A - Platter/s B - Read/Write Head/s C - Actuator Arm/s D - Actuator E - Spindle

How A Hard Drive WorksHow A Hard Drive Works The banks of polarized molecules in the disk's The banks of polarized molecules in the disk's

coating are themselves tiny magnets that create coating are themselves tiny magnets that create a magnetic field through which the read/write a magnetic field through which the read/write head passes. The movement of the head head passes. The movement of the head through the magnetic field generates an through the magnetic field generates an electrical current that travels in one direction or electrical current that travels in one direction or the other through the wires leading from the the other through the wires leading from the head. The direction the current flows depends head. The direction the current flows depends on the polarities pf the bands. By sensing the on the polarities pf the bands. By sensing the directions in which the current is moving, the directions in which the current is moving, the computer can tell if the read / write head is computer can tell if the read / write head is passing over a 1 or a 0.passing over a 1 or a 0.

How A Hard Drive WorksHow A Hard Drive Works

Hard Drive MathHard Drive Math kilo is 1,000 in the decimal system.kilo is 1,000 in the decimal system.

Hence, one kilometer is a 1,000 meters and one kilogram is 1,000 Hence, one kilometer is a 1,000 meters and one kilogram is 1,000 grams because we are using the decimal system.grams because we are using the decimal system.

However, in the binary system, a kilo is 1,024.However, in the binary system, a kilo is 1,024.

As you can see the kilo in the binary system (1,024) is close in value As you can see the kilo in the binary system (1,024) is close in value to the kilo in the decimal system (1,000) and many people use 1 to the kilo in the decimal system (1,000) and many people use 1 kilobyte as a synonym of 1,000 bytes.kilobyte as a synonym of 1,000 bytes.

Therefore, a file of 6 KB contains 6,144 bytes (6 x 1024 bytes) not Therefore, a file of 6 KB contains 6,144 bytes (6 x 1024 bytes) not 6000 bytes. A 2.2 Gig hard drive partition would have 6000 bytes. A 2.2 Gig hard drive partition would have 2,252,800,000 bytes or would be 2.2528 GB.2,252,800,000 bytes or would be 2.2528 GB.

Hard Drive ControllersHard Drive Controllers IDEIDE

Integrated Device Electronics. A hard drive interface system developed Integrated Device Electronics. A hard drive interface system developed by a group of manufacturers whereby the controller system was by a group of manufacturers whereby the controller system was integrated into the drive; all of the components were within the hard integrated into the drive; all of the components were within the hard drive unit removing the need to have a separate controller.drive unit removing the need to have a separate controller.

It should be NOTED that most older 40 wire IDE cables DO NOT It should be NOTED that most older 40 wire IDE cables DO NOT support Cable Select!support Cable Select!

EIDEEIDE A design that improves on the Drive limitations of the IDE design. EIDE A design that improves on the Drive limitations of the IDE design. EIDE

designs can use up to four devices (split into two pairs). For each pair of designs can use up to four devices (split into two pairs). For each pair of devices, one of the devices is the master; the drive electronics on the devices, one of the devices is the master; the drive electronics on the master control both the master drive and (if applicable) the secondary master control both the master drive and (if applicable) the secondary slave unit attached. slave unit attached.

It should be NOTED that the Master Drive should be plugged into the It should be NOTED that the Master Drive should be plugged into the end of the cable if you want it to be a master device and are setting it to end of the cable if you want it to be a master device and are setting it to Cable Select!Cable Select!

Hard Drive ControllersHard Drive Controllers

SCSISCSI Small Computer Systems Interface, a high-speed Small Computer Systems Interface, a high-speed

communications protocol that allows computers, communications protocol that allows computers, samplers, and disk drives to communicate with one samplers, and disk drives to communicate with one another. Pronounced "scuzzy.“another. Pronounced "scuzzy.“

It should be noted that when using SCSI interfaces It should be noted that when using SCSI interfaces you can have up to 7 (or even 15) devices. you can have up to 7 (or even 15) devices.

SATASATA Serial ATA is an evolutionary replacement for the Serial ATA is an evolutionary replacement for the

Parallel ATA physical storage interface. Parallel ATA physical storage interface.

Hard Drive ControllersHard Drive Controllers RAID (Redundant Array of Independent Disks). A collection of disk drives RAID (Redundant Array of Independent Disks). A collection of disk drives

that offers increased performance and fault tolerance. There are a number that offers increased performance and fault tolerance. There are a number of different RAID levels. The three most commonly used are 0, 1, and 5:of different RAID levels. The three most commonly used are 0, 1, and 5:

* Level 0: striping without parity (spreading out blocks of each file * Level 0: striping without parity (spreading out blocks of each file across multiple disks).across multiple disks).

* Level 1: disk mirroring or duplexing.* Level 1: disk mirroring or duplexing. * Level 2: bit-level striping with parity* Level 2: bit-level striping with parity * Level 3: byte-level striping with dedicated parity. Same as Level 0, * Level 3: byte-level striping with dedicated parity. Same as Level 0,

but also reserves one dedicated disk for error correction data. It provides but also reserves one dedicated disk for error correction data. It provides good performance and some level of fault tolerance.good performance and some level of fault tolerance.

* Level 4: block-level striping with dedicated parity* Level 4: block-level striping with dedicated parity * Level 5: block-level striping with distributed parity* Level 5: block-level striping with distributed parity * Level 6: block-level striping with two sets of distributed parity for extra * Level 6: block-level striping with two sets of distributed parity for extra

fault tolerancefault tolerance * Level 7: Asynchronous, cached striping with dedicated parity * Level 7: Asynchronous, cached striping with dedicated parity

Configuring Hard DrivesConfiguring Hard Drives

Most IDE drives have jumpers that select Most IDE drives have jumpers that select the "master" or "slave" role on the the "master" or "slave" role on the controller, but modern drives also have a controller, but modern drives also have a "CS" or "Cable select" pin. This allows the "CS" or "Cable select" pin. This allows the IDE cable IDE cable itself to select the drive's role: itself to select the drive's role: all drives that have the CS jumper set all drives that have the CS jumper set allow the allow the cablecable to choose which device is to choose which device is the master and which is the slave. the master and which is the slave.

Configuring Hard DrivesConfiguring Hard Drives

When a drive is on the cable alone it When a drive is on the cable alone it should be set to Master OR Cable Select – should be set to Master OR Cable Select – providing it is plugged into the end providing it is plugged into the end connector.connector.

When there are two drives, the drive that When there are two drives, the drive that should be bootable should be set to should be bootable should be set to Master or Cable Select – providing it is Master or Cable Select – providing it is plugged into the end connector.plugged into the end connector.

Configuring Hard DrivesConfiguring Hard Drives

When there are two drives, one that is When there are two drives, one that is bootable, one that is not; The bootable bootable, one that is not; The bootable drive should be set to Master or Cable drive should be set to Master or Cable Select – providing it is plugged into the Select – providing it is plugged into the end connector.end connector.

When there are two drive, both that are When there are two drive, both that are bootable; They should be both set to bootable; They should be both set to Cable Select.Cable Select.

Configuring Hard DrivesConfiguring Hard DrivesIDE / EIDEIDE / EIDE

Configuring Hard DrivesConfiguring Hard Drives

SATA does not require Master Slave settings. SATA does not require Master Slave settings. SATA drops the master/slave shared bus of SATA drops the master/slave shared bus of PATA, giving each device a dedicated cable and PATA, giving each device a dedicated cable and dedicated bandwidth. While this requires twice dedicated bandwidth. While this requires twice the number of host controllers to support the the number of host controllers to support the same number of SATA devicessame number of SATA devices

Partitioning A Hard DiskPartitioning A Hard Disk Primary Partitions:Primary Partitions:

A primary partition may contain an operating system along with any number of data A primary partition may contain an operating system along with any number of data files (for example, program files, user files, and so forth). Before an OS is installed, files (for example, program files, user files, and so forth). Before an OS is installed, the primary partition must be logically formatted with a file system compatible to the the primary partition must be logically formatted with a file system compatible to the OS.OS.

If you have multiple primary partitions on your hard disk, only one primary partition If you have multiple primary partitions on your hard disk, only one primary partition may be bootable and active at a time. The active partition is the partition from which may be bootable and active at a time. The active partition is the partition from which an OS is booted at computer startup. an OS is booted at computer startup.

Primary partitions other than the active partition are hidden if their file system type is Primary partitions other than the active partition are hidden if their file system type is not recognized, preventing their data from being accessed. Thus, the data in a not recognized, preventing their data from being accessed. Thus, the data in a primary partition can be accessed (for all practical purposes) only by the OS installed primary partition can be accessed (for all practical purposes) only by the OS installed on that partition. on that partition.

If you plan to install more than one operating system on your hard disk, you probably If you plan to install more than one operating system on your hard disk, you probably need to create multiple primary partitions; most operating systems can be booted only need to create multiple primary partitions; most operating systems can be booted only from a primary partition. from a primary partition.

Partitioning A Hard DiskPartitioning A Hard Disk Extended Partitions:Extended Partitions:

The extended partition was invented as a way of getting The extended partition was invented as a way of getting around the arbitrary four-partition limit. An extended partition around the arbitrary four-partition limit. An extended partition is essentially a container in which you can further physically is essentially a container in which you can further physically divide your disk space by creating an unlimited number of logical divide your disk space by creating an unlimited number of logical partitions.partitions.

An extended partition does not directly hold data. You An extended partition does not directly hold data. You must create logical partitions within the extended partition must create logical partitions within the extended partition in order to store data. Once created, logical partitions in order to store data. Once created, logical partitions must be logically formatted, but each can use a different file must be logically formatted, but each can use a different file system.system.

Partitioning A Hard DiskPartitioning A Hard Disk

Logical PartitionsLogical Partitions

Logical partitions may exist only Logical partitions may exist only within an extended partition and are meant within an extended partition and are meant to contain only data files and operating to contain only data files and operating systems that can be booted from a logical systems that can be booted from a logical partition (for example, Linux, Windows NT, partition (for example, Linux, Windows NT, and so forth).and so forth).

Formatting a hard disk arranges the magnetic media in a pattern so that the Formatting a hard disk arranges the magnetic media in a pattern so that the operating system knows where it is in relation to the data on the disks operating system knows where it is in relation to the data on the disks surfacesurface

When doing a clean install of Windows XP, after you’ve selected the When doing a clean install of Windows XP, after you’ve selected the partition where XP will be installed, you are presented with the option to partition where XP will be installed, you are presented with the option to format the drive or partition. The format options are:format the drive or partition. The format options are:

Format the partition using the NTFS file system (Quick)Format the partition using the NTFS file system (Quick) Format the partition using the FAT file system (Quick)Format the partition using the FAT file system (Quick) Format the partition using the NTFS file systemFormat the partition using the NTFS file system Leave the current file system intact (no changes)Leave the current file system intact (no changes)

The difference between the regular format versus the quick format is The difference between the regular format versus the quick format is whether or not the volume is scanned for bad sectors using the chkdsk whether or not the volume is scanned for bad sectors using the chkdsk command. Both methods remove the files from the volume.command. Both methods remove the files from the volume.

Formatting A Hard DiskFormatting A Hard Disk

Format ChoicesFormat Choices FAT16FAT16 The FAT16 file system was introduced way back with MS–DOS in The FAT16 file system was introduced way back with MS–DOS in

1981. It was designed originally to handle files on a floppy drive, and 1981. It was designed originally to handle files on a floppy drive, and has had minor modifications over the years so it can handle hard has had minor modifications over the years so it can handle hard disks, and even file names longer than the original limitation of 8.3 disks, and even file names longer than the original limitation of 8.3 characters, but it's still the lowest common denominator. characters, but it's still the lowest common denominator.

The biggest advantage of FAT16 is that it is compatible across a The biggest advantage of FAT16 is that it is compatible across a wide variety of operating systems, including Windows 95/98/Me, wide variety of operating systems, including Windows 95/98/Me, OS/2, Linux, and some versions of UNIX. By OS/2, Linux, and some versions of UNIX. By default default many of these many of these OS’s can read FAT16!OS’s can read FAT16!

The biggest problem of FAT16 is that it has a fixed maximum The biggest problem of FAT16 is that it has a fixed maximum number of clusters per partition, so as hard disks get bigger and number of clusters per partition, so as hard disks get bigger and bigger, the size of each cluster has to get larger. In a 2–GB partition, bigger, the size of each cluster has to get larger. In a 2–GB partition, each cluster is 32 kilobytes, meaning that even the smallest file on each cluster is 32 kilobytes, meaning that even the smallest file on the partition will take up 32 KB of space. FAT16 also doesn't support the partition will take up 32 KB of space. FAT16 also doesn't support compression, encryption, or advanced security using access control compression, encryption, or advanced security using access control lists.lists.

Format ChoicesFormat Choices FAT32FAT32 The FAT32 file system, originally introduced in Windows 95 Service The FAT32 file system, originally introduced in Windows 95 Service

Pack 2, is really just an extension of the original FAT16 file system Pack 2, is really just an extension of the original FAT16 file system that provides for a much larger number of clusters per partition. As that provides for a much larger number of clusters per partition. As such, it greatly improves the overall disk utilization when compared such, it greatly improves the overall disk utilization when compared to a FAT16 file system. to a FAT16 file system.

However, FAT32 shares all of the other limitations of FAT16, and However, FAT32 shares all of the other limitations of FAT16, and adds an important additional limitation—many operating systems adds an important additional limitation—many operating systems that can recognize FAT16 will not work with FAT32—most notably that can recognize FAT16 will not work with FAT32—most notably Windows NT, but also Linux and UNIX as well. Windows NT, but also Linux and UNIX as well.

Now this isn't a problem if you're running FAT32 on a Windows XP Now this isn't a problem if you're running FAT32 on a Windows XP computer and sharing your drive out to other computers on your computer and sharing your drive out to other computers on your network—they don't need to know (and generally don't really care) network—they don't need to know (and generally don't really care) what your underlying file system is. what your underlying file system is.

Format ChoicesFormat Choices NTFSNTFS

The NTFS file system, introduced with first version of Windows NT, The NTFS file system, introduced with first version of Windows NT, is a completely different file system from FAT. It provides for greatly is a completely different file system from FAT. It provides for greatly increased security, file–by–file compression, quotas, and even increased security, file–by–file compression, quotas, and even encryption. It is the default file system for new installations of encryption. It is the default file system for new installations of Windows XP.Windows XP.

There are DOS and Legacy Windows drivers to allow older systems There are DOS and Legacy Windows drivers to allow older systems to read NTFS. Unix/Linux also has a NTFS driver, so these OS’s to read NTFS. Unix/Linux also has a NTFS driver, so these OS’s can read NTFS partitions.can read NTFS partitions.

Hard Drive MaintenanceHard Drive Maintenance ChkdskChkdsk

If your Windows operating system experiences a If your Windows operating system experiences a problem, you can use the Chkdsk disk repair utility problem, you can use the Chkdsk disk repair utility included in the operating system to check the file included in the operating system to check the file system on each logical partition and check the disk system on each logical partition and check the disk surface for unreadable or corrupted sectors. surface for unreadable or corrupted sectors.

The Chkdsk utility creates and displays a status report The Chkdsk utility creates and displays a status report for a disk based on the file system used. Chkdsk also for a disk based on the file system used. Chkdsk also lists and corrects errors on the disk. You can run lists and corrects errors on the disk. You can run Chkdsk from your Windows operating system. If you Chkdsk from your Windows operating system. If you cannot start your operating system because of the cannot start your operating system because of the problem, you can run Chkdsk from the Windows problem, you can run Chkdsk from the Windows Recovery Console. Recovery Console.

Hard Drive MaintenanceHard Drive Maintenance

CleanMGRCleanMGRCleanmgr.exe is designed to clear Cleanmgr.exe is designed to clear

unnecessary files from your computer's hard unnecessary files from your computer's hard disk. You can configure Cleanmgr.exe with disk. You can configure Cleanmgr.exe with command-line switches to clean up the files command-line switches to clean up the files you want. You can then schedule the task to you want. You can then schedule the task to run at a specific time by using the Scheduled run at a specific time by using the Scheduled Tasks tool. Tasks tool.

It is important to clean your disk of It is important to clean your disk of unnecessary files BEFORE you defrag it!unnecessary files BEFORE you defrag it!

Hard Drive MaintenanceHard Drive Maintenance Sometimes when you install a program or create a data file, the file Sometimes when you install a program or create a data file, the file

ends up chopped up into chunks and stored in multiple locations on ends up chopped up into chunks and stored in multiple locations on the disk. This is called the disk. This is called fragmentationfragmentation. .

There's a simple solution to file fragmentation: use Windows Disk There's a simple solution to file fragmentation: use Windows Disk Defragmenter (Start –> Programs –> Accessories –> System Tools Defragmenter (Start –> Programs –> Accessories –> System Tools –> Disk Defragmenter). This utility, commonly called Defrag, gathers –> Disk Defragmenter). This utility, commonly called Defrag, gathers all the scattered file fragments and writes them into adjacent all the scattered file fragments and writes them into adjacent clusters, so each file occupies a contiguous section of the disk.clusters, so each file occupies a contiguous section of the disk.

Defrag works by moving slabs of data to unused parts of the disk, in Defrag works by moving slabs of data to unused parts of the disk, in order to open up a large free section of space. It then assembles the order to open up a large free section of space. It then assembles the fragmented parts of a file and writes them in one complete piece to fragmented parts of a file and writes them in one complete piece to the cleared space; it then does the same with the next file; and so the cleared space; it then does the same with the next file; and so on until the entire disk is defragmented.on until the entire disk is defragmented.

Hard Drive MaintenanceHard Drive Maintenance

Defrag LimitationsDefrag LimitationsDefrag cannot defragment open files or Defrag cannot defragment open files or

Operating System Files that are in use.Operating System Files that are in use.To over come this limitation you can use To over come this limitation you can use

specialty software programs.specialty software programs.Pagedfrg – is a utility to defragment the Pagedfrg – is a utility to defragment the

pagefilespagefilesContig – is a utility to defragment individual Contig – is a utility to defragment individual

files.files.

QuestionsQuestions