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					Managing Storage
          Lesson 3
Objectives
Storage
• While you need sufficient processing power
  and a sufficient amount of RAM, you will also
  most likely need a large amount of storage.
• Although simple servers usually require that
  you install Windows Server on a local IDE
  (parallel and serial) or SCSI hard drive, more
  complex systems may use a form of RAID or
  attached remote computer storage devices
  such as a storage area network (SAN) or
  network attached storage (NAS).
RAID
• Because most drives are half-electronic and half-
  mechanical devices, you can connect multiple drives to
  special controllers to provide data production, system
  reliability, and better performance.
• A redundant array of independent disks (RAID) uses
  two or more drives in combination to create a fault-
  tolerant system that protects against physical hard
  drive failure and increases hard drive performance.
• A RAID can be accomplished with either hardware or
  software and is usually used with network servers.
RAID 0
• RAID 0 stripes data across all drives.
• With striping, all available hard drives are
  combined into a single large virtual file system,
  with the file system’s blocks arrayed so that they
  are spread evenly across all the drives.
• Unfortunately, with RAID 0, there is no parity
  control or fault tolerance; therefore, it is not a true
  form of RAID.
• However, RAID 0 does have several advantages
  because it offers increased performance through
  load balancing.
RAID 1
• RAID 1 is sometimes known as disk mirroring.
• Disk mirroring copies a disk or partition onto a
  second hard drive. Specifically, as information is
  written, it is written to both hard drives
  simultaneously.
• If one of the hard drives fails, the PC will still
  function because it can access the other hard
  drive.
   – Then, should you later replace the failed drive,
      data will be copied from the remaining good
      drive to the new drive.
RAID 5
• RAID 5, which is similar to striping, except the space
  equivalent to one of the hard drives is used for parity
  (error correction) to provide fault tolerance.
• To increase performance, the error correction function
  is spread across all hard drives in the array to avoid
  having one drive doing all the work in calculating the
  parity bits.
• Therefore if one drive fails, you can still continue
  working because parity calculations with the remaining
  drives will fill in any missing data.
• Later, when the failed drive is replaced, the missing
  information will be rebuilt.
Hybrid RAID
• There are two other forms of RAID worth
  mentioning, both of which are considered
  hybrid or nested RAIDs:
  – RAID 1+0 is a mirrored dataset (RAID 1),
    which is then striped (RAID 0).
  – RAID 0+1 is a striped dataset (RAID 0), which
    is then mirrored (RAID 1).
Hot Spare
• A hot spare is much like it sounds. When
  drives need to be fault tolerant, you can
  combine a hot spare drive with a RAID.
• Then, if a drive fails, the system will
  automatically grab the hot spare drive to
  replace the failed drive and rebuild or
  restore the missing data.
Network Attached Storage
• Network attached storage (NAS) is a file-level
  data storage device that is connected to a
  computer network to provide shared drives
  or folders, usually using SMB/CIFS.
• NAS devices usually contain multiple drives
  in a form of RAID for fault tolerance and are
  managed usually using a web interface.
Storage Area Network
• A storage area network (SAN) is an architecture
  used for disk arrays, tape libraries, and optical
  jukeboxes to appear as locally attached drives on a
  server.
• A SAN always uses some form of RAID and other
  technology to make the system redundant against
  drive failure and to offer high performance.
• SANs also usually contain spare drives.
• To provide a high level of data throughput, SANs
  use the SCSI protocol and either iSCSI or Fibre
  Channel interface.
Host Bus Adapter
• A host adapter, sometimes referred to as
  host bus adapter (HBA), connects a host
  system such as a computer to a network or
  storage device.
• It is primarily used to refer to connecting
  SCSI, Fibre Channel, and eSATA devices
LUNs
• Logical unit numbers (usually referred to as
  LUNs) allow a SAN to break its storage down
  into manageable pieces, which are then
  assigned to one or more servers in the SAN.
• It is a logical reference that can comprise a
  disk, a section of a disk, a whole disk array, or
  a section of a disk array.
• LUNs serve as logical identifiers through
  which you can assign access and control
  privileges.
Fibre Channel
• Optic fiber cabling offers higher bandwidths and
  can be used over longer distances than copper
  cabling because signals travel with less loss and
  are immune to electromagnetic interference.
• Fibre Channel or FC is a gigabit-speed technology
  primarily used for storage networking.
• It uses a Fibre Channel Protocol (FCP) as its
  transport protocol, which allows SCSI commands to
  be issued over Fibre Channel.
iSCSI
• Internet Small Computing System Interface or iSCSI
  is an Internet Protocol (IP)-based storage networking
  standard for linking data storage facilities.
• iSCSI allows clients to send SCSI commands over a
  TCP/IP network using TCP port 3260.
• Similar to Fibre Channel, iSCSI can communicate
  using Gigabit Ethernet or Fibre, and it can connect a
  SAN to multiple servers over a distance.
• Although iSCSI uses normal network technology to
  communicate, the network adaptor must be
  dedicated to iSCSI.
iSCSI Initiator Software
Storage Explorer
• Windows Server 2008 includes Storage Explorer
  and Storage Manager for SANs to manage Fibre
  Channel, iSCSI fabrics, and LUNs.
• Storage Explorer allows you to view and manage
  the Fibre Channel and iSCSI fabrics that are
  available in your SAN.
• Storage Explorer can display detailed information
  about servers connected to the SAN, as well as
  components in the fabrics such as host bus
  adapters (HBAs), Fibre Channel switches, and iSCSI
  initiators and targets.
Storage Explorer
Disk Structure
• Before you use a disk, you must prepare the
  disk for usage by creating partitions or
  volumes and formatting the disk.
• When you want to use a disk in Windows,
  you have several choices to make:
  – Disk partitioning style
  – Disk type
  – Type of volume
  – File system
Partitioning
• Partitioning is defining and dividing a physical or
  virtual disk into logical volumes called partitions.
• Each partition functions as if it were a separate
  disk drive, which can be assigned a drive letter.
• To keep track of how a disk is divided, the disk
  uses a partition table.
• Formatting a disk prepares the volume’s file
  system by creating a file allocation table to keep
  track of the files and folders on the volume.
Partitioning Style
• Partitioning style refers to the method that
  Windows uses to organize partitions on a
  disk.
• Windows Server 2008 supports two types of
  disk partitioning styles:
  – Master Boot Record (MBR)
  – GUID Partition Table (GPT)
Windows Hard Disk Storage
• Most versions of Windows servers—including
  Windows Server 2008—support two types of
  hard disk storage
  – Basic disks are the traditional disk type,
  – Dynamic disks offer software-based RAID
    and the ability to resize volumes without
    rebooting.
Dynamic Disks
• Dynamic disks support five types of volumes:
  – Simple volume
  – Spanned volume
  – Striped volume
  – Mirrored volume
  – RAID-5 volume
File System
• A file system is a method of storing and
  organizing computer files and the data they
  contain to make it easy to find and access
  this information.
• A file system also maintains the physical
  location of the files so that you can find and
  access the files in the future.
• Windows Server 2008 supports FAT16,
  FAT32, and NTFS file systems on hard
  drives.
FAT16 and FAT32
• FAT16, sometimes referred to generically as File
  Allocation Table (FAT), is a simple file system that
  uses minimum memory and was even used with
  DOS.
   – Unfortunately, FAT can only support volumes up
     to 2 GB.
• FAT32 was released with the second major release
  of Windows 95. Although this file system can
  support larger drives, today’s Windows versions
  support volumes only up to 32 GB.
NTFS File System
• As mentioned earlier, New Technology File System
  (NTFS) is the preferred file system, largely because
  it supports both a much larger hard disk (up to 16
  exabytes) and long file names.
• NTFS is more fault tolerant than previous file
  systems used in Windows because it uses
  journaling to make sure that disk transactions are
  written properly before they can be recognized.
• NTFS offers better security through permissions
  and encryption.
Disk Management
• The main disk management tool in Windows
  Server 2008 is the MMC snap-in called Disk
  Management, which is also part of the
  Computer and Management consoles.
• In addition, you can use a diskpart.exe and
  the Format command to partition and format
  a drive, as well as Windows Explorer to
  format a drive.
Disk Management
Initializing a Disk
Converting to a Dynamic Disk
Creating a Simple Volume
Assigning Drive Letter or Path
Formatting Drive
Extending Volume
Summary
• Today’s drives are either IDE drives (mostly found
  on consumer computers) or SCSI drives (mostly
  found in servers).
• A redundant array of independent disks (RAID)
  uses two or more drives in combination to create a
  fault-tolerant system that protects against physical
  hard drive failure and increase hard drive
  performance.
Summary
• Network attached storage (NAS) is a file-level data
  storage device that is connected to a computer
  network to provide shared drives or folders, usually
  using SMB.
• A storage area network (SAN) is an architecture
  used for disk arrays, tape libraries, and optical
  jukeboxes to appear as locally attached drives on a
  server.
• A host adapter, sometimes referred to as host bus
  adapter (HBA), connects a host system such as a
  computer to a network or storage devices.
Summary
• A file system is a method of storing and organizing
  computer files and the data they contain to make it
  easy to find and access this information. A file system
  also maintains the physical location of the files so you
  can find and access the files in the future.
• Currently, NTFS is the preferred file system, in part
  because it supports much larger hard disks (up to 16
  exabytes) and long filenames.
• NTFS is a journaling file system that makes sure a disk
  transaction is written properly before it is recognized.
• NTFS offers better security through permissions and
  encryption.

				
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posted:9/29/2012
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