Transcript Week 8 lesson06

Planning Storage Solutions
Lesson 6
Skills Matrix
Technology Skill
Objective Domain
Objective #
Planning Server Storage
Plan storage
5.1
Server Storage
• A Windows server can conceivably perform its
tasks using the same type of storage as a
workstation, that is, one or more standard hard
disks connected to a standard drive interface such
as Serial ATA (SATA).
• The I/O burdens of a server are quite different from
those of a workstation, and a standard storage
subsystem can easily be overwhelmed by file
requests from dozens or hundreds of users.
• In addition, standard hard disks offer no fault
tolerance and are limited in their scalability.
Server Storage
• There are a variety of storage technologies that are
better suited for server use, and the process of
designing a storage solution for a server depends
on several factors, including the following:
– The amount of storage the server needs.
– The number of users that will be accessing the
server at the same time.
– The sensitivity of the data to be stored on the
server.
– The importance of the data to the organization.
Estimating Storage Requirements
• The amount of storage space you need in a
server depends on a variety of factors, not
just the initial requirements of your
applications and users.
– Operating system
– Paging file
– Memory dump
– Log files
– Shadow copies
– Fault tolerance
Disk Technology
• Direct-Attached Storage
– Advanced Technology Attachment (ATA)
•Parallel ATA
•Serial ATA
– Small Computer System Interface (SCSI)
Logital Unit Numbers (LUN)
• To use SCSI on a server, all of the devices and host
adapters must support the same standard.
• You connect SCSI devices to a host adapter using a daisy
chain cable arrangement called a SCSI bus.
• Many host adapters enable you to connect both internal
and external devices, so you can expand the bus as
needed, even if the computer case does not have room for
additional drives.
• Every device on a SCSI bus has an identifier called a SCSI
ID, which the host adapter uses to send commands to the
device.
• Subcomponents of a SCSI device, such as individual drives
in an array, are identified using logical unit numbers (LUNs).
External Drive Arrays
• High capacity servers often store hard drives
in a separate housing, called an external
drive array, which typically incorporates a
disk controller, power supply, cooling fans,
and cache memory into an independent unit.
• Drive arrays can connect to a computer
using a disk interface, such as SCSI (Small
Computer System Interface), IEEE 1394
(FireWire), or USB 2.0, or a network
interface, such as iSCSI or Fibre Channel.
Storage Area Network (SAN)
Network Attached Storage
Planning for Storage Fault Tolerance
• Redundant Array of Independent Disks
– Disk mirroring (RAID 1)
•Disk duplexing
– Strip set with Distributed Parity (RAID 5)
Windows Disk Settings
• Select a partitioning style (MBR or GPT).
• Select a disk type (Basic versus Dynamic).
• Divide the disk into partitions or volumes.
• Format the partition with a file system.
Partition Style
• Windows Server 2008 computers can use either
one of the following two hard disk partition styles:
– MBR — The MBR partition style has been around
since before Windows and is still the default
partition style for x86-based and x64-based
computers.
– GPT — GPT has also been around for a while, but no
x86 version of Windows prior to Windows Server
2008 and Windows Vista supports it. (Windows XP
Professional x64 Edition does support GPT.) Now
you can use the GPT partition style on x86-, as well
as x64-based, computers.
Partition Style
Basic Disks
• A basic disk uses primary partitions,
extended partitions, and logical drives to
organize data.
• A primary partition appears to the operating
system as though it is a physically separate
disk and can host an operating system, in
which case it is known as the active
partition.
Basic Disks
• During the operating system installation, the setup
program creates a system partition and a boot
partition.
• The system partition contains hardware-related
files that the computer uses to start.
• The boot partition contains the operating system
files, which are stored in the Windows file folder.
• In most cases, these two partitions are one and the
same, the active primary partition that Windows
uses when starting.
• The active partition tells the computer which
system partition and operating system it should
use to start Windows.
Partitions
Volume Types
• A dynamic disk can contain an unlimited
number of volumes that function much like
primary partitions on a basic disk, but you
cannot mark an existing dynamic disk as
active.
– Simple Volume
– Spanned Volume
– Striped Volume
– Mirrored Volume
– RAID-5 Volume
Volume Size
• Although Windows Server 2008 can support
dynamic volumes as large as 64 terabytes,
this does not mean that you should create
volumes that big, even if you have a server
with that much storage.
• To facilitate the maintenance and
administration processes, it is usually
preferable to split your server’s storage into
volumes of manageable size, rather than
create a single, gigantic volume.
Disk Management
• Disk Management is a Microsoft Management
Console (MMC) snap-in that you use to perform
disk-related tasks, such as the following:
– Initializing disks.
– Selecting a partition style.
– Converting basic disks to dynamic disks.
– Creating partitions and volumes.
– Extending, shrinking, and deleting volumes.
– Formatting partitions and volumes.
– Assigning and changing driver letters and paths.
– Examining and managing physical disk properties,
such as disk quotas, folder sharing, and error
checking.
Disk Management
The Initialize Disk Dialog Box
Disk Management Snap-in
with a Newly Initialized Disk
The Convert to Dynamic Disk Dialog Box
The Disk to Convert Dialog Box
The Convert Details Dialog Box
The Disk Management Information Box
The Specify Volume Size Page
The Assign Drive Letter or Path Page
The Format Partition Page
The Select Disks Pages
Extending Volumes
• Windows Server 2008 extends existing
volumes by expanding them into adjacent
unallocated space on the same disk.
• When you extend a simple volume across
multiple disks, the simple volume becomes
a spanned volume.
• You cannot extend striped volumes.
Extending Volumes
• To extend a volume on a basic disk, the system
must meet the following requirements:
– A volume of a basic disk must be either unformatted
or formatted with the NTFS file system.
– If you extend a volume that is actually a logical
drive, the console first consumes the contiguous
free space remaining in the extended partition.
– You can extend logical drives, boot volumes, or
system volumes only into contiguous space, and
only if the hard disk can be upgraded to a dynamic
disk.
Extending Volumes
• To extend a volume on a dynamic disk, the system
must meet these requirements:
– When extending a simple volume, you can use only
the available space on the same disk, if the volume
is to remain simple.
– You can extend a simple volume across additional
disks if it is not a system volume or a boot volume.
– You can extend a simple or spanned volume if it
does not have a file system (a raw volume) or if you
formatted it using the NTFS file system.
– You cannot extend mirrored or RAID-5 volumes.
Shrinking Volumes
• When shrinking volumes, the Disk
Management console frees up space at the
end of the volume, relocating the existing
volume’s files, if necessary.
• The console then converts that free space to
new unallocated space on the disk.
Shrinking Volumes
• To shrink basic disk volumes and simple or
spanned dynamic disk volumes, the system must
meet the following requirements:
– The existing volume must not be full and must
contain the specified amount of available free space
for shrinking.
– The volume must not be a raw partition (one without
a file system).
– You can shrink a volume only if you formatted it
using the NTFS file system.
– You cannot shrink striped, mirrored, or RAID-5
volumes.
– You should always defragment a volume before you
attempt to shrink it.
Storage Area Network
• RAID is a proven high availability technology
that was first defined in 1988, but serverattached RAID arrays are subject to
scalability problems.
• You can install only so many drives into a
single computer.
• The terminated SCSI bus that was originally
used for connections to external drive arrays
is limited to 16 devices and a maximum
length of 25 yards.
Storage Area Network
Multiple Servers Connected to a SAN
Fibre Channel
• Fibre Channel is a high-speed serial networking
technology, originally designed for use with
supercomputers but now associated primarily with
storage area networking.
• Fibre Channel is a versatile technology, supporting
various network media, transmission speeds,
topologies, and upper level protocols.
• Its primary disadvantage is that it requires
specialized hardware that can be extremely
expensive.
Fibre Channel Media
• A Fibre Channel network can use a variety of
network media.
• Copper alternatives include video or miniature
coaxial cable and, more commonly, shielded
twisted pair (STP) with DB-9 or HSSDC (High Speed
Serial Data Connection) cable connectors.
• Fiber optic alternatives include 62.5- or 50-ohm
multimode and 7- or 9-ohm singlemode, all using
LC or SC connectors.
• Because Fibre Channel uses serial instead of
parallel signaling, it can span much longer
distances than a pure SCSI connection, up to 50
kilometers or more in some cases.
Fiber Channel Speeds
• Transmission speeds for Fibre Channel
networks range from 133 Mbps (megabits
per second) to 1 Gbps (gigabit per second)
for copper cables, and up to 10 Gbps for
fiber optic.
• Maximum speeds depend on the type of
cable the network uses, the lengths of the
cable segments, and, in the case of fiber
optic, the type of laser used to transmit the
signals.
Fibre Channel Topologies
• Point-to-point (FC-P2P) — Consists of two
devices only, directly connected with a single
cable.
• Arbitrated loop (FC-AL) — Consists of up to
127 devices, connected in a loop topology,
similar to that of a token ring network.
– The loop can be physical, with each device
connected to the next device, or virtual, with
each device connected to a hub that
implements the loop.
Fibre Channel Topologies
• Switched fabric (FC-SW) — Consists of up to
16,777,216 (224) devices, each of which is
connected to a Fibre Channel switch.
• Unlike Ethernet switches, Fibre Channel
switches provide redundant paths between
the connected devices, forming a topology
called a mesh or fabric.
• If a switch or a connection between switches
fails, data can find an alternate path through
the fabric to its destination.
iSCSI
• iSCSI is an alternative storage area
networking technology that enables servers
and storage devices to exchange SCSI traffic
using a standard IP network instead of a
dedicated Fibre Channel network.
• Because iSCSI uses a standard IP network
for its lower layer functionality, you can use
the same cables, network adapters,
switches, and routers for a SAN as you would
for a LAN or wide area network (WAN),
without any modifications.
iSCSI
• iSCSI communication is based on two
elements:
– Initiators
– Targets
iSCSI Initiator
• Initiates the SCSI communication process.
• Is a hardware or software device running on a computer
that accesses the storage devices on the SAN.
• On an iSCSI network, the initiator takes the place of the
host adapter that traditional SCSI implementations use
to connect storage devices to a computer.
• The initiator receives I/O requests from the operating
system and sends them, in the form of SCSI commands,
to specific storage devices on the SAN.
• The only difference between an iSCSI initiator and a SCSI
host adapter is that the initiator packages the SCSI traffic
in TCP/IP packets, instead of using the native SCSI
protocols.
iSCSI Target
• Integrated into a drive array or computer.
• The target receives SCSI commands from the
initiator and passes them to a storage device,
which is represented by a logical unit number
(LUN).
• A LUN is essentially an address that SCSI devices
use to identify a specific storage resource.
• A single LUN can represent an entire hard disk,
part of a disk, or a slice of a RAID array.
• Therefore, a single computer or drive array can
have many LUNs, represented by multiple targets.
iSNSs
• After the initiators and targets are in place, the only
problem remaining in iSCSI communications is how
the two locate each other.
• The Internet Storage Name Service (iSNS) makes
this possible by registering the presence of
initiators and targets on a SAN and responding to
queries from iSNS clients.
• Windows Server 2008 includes an iSNS
implementation as a feature, which can provide
the identification service for an entire SAN.
iSNS Components
• iSNS server — Receives and processes registration
requests and queries from clients on the SAN, using
the iSNS database as an information store.
• iSNS database — Information store on an iSNS server
that contains data supplied by client registrations. The
server retrieves the data to respond to client queries.
• iSNS clients — Component in iSCSI initiators and
targets that registers information about itself with an
iSNS server and sends queries to the server for
information about other clients.
• iSNS Protocol (iSNSP) — Protocol used for all
registration and query traffic between iSNS servers and
clients.
The Storage Manager for SANs Console
Create LUNs in the Storage
Manager for SANs Console
Displaying Subsystem Information
Displaying Drive Information
The Storage Explorer Console
Configuring an iSCSI Initiator
Summary
• Windows Server 2008 supports two hard
disk partition types: MBR and GPT; two disk
types: basic and dynamic; five volume types:
simple, striped, spanned, mirrored, and
RAID-5; and two file systems: NTFS and FAT.
• The Disk Management snap-in is the primary
interface you use to initialize, partition, and
format disks.
Summary
• A storage area network (SAN) is a network
dedicated solely to high-speed connections
between servers and storage devices.
• Fibre Channel is a high-speed serial
networking technology that was originally
designed for use with supercomputers but is
now associated primarily with storage area
networking.
Summary
• iSCSI is an alternative storage area
networking technology that enables servers
and storage devices to exchange SCSI traffic
using a standard IP network instead of a
dedicated Fibre Channel network.
Summary
• An iSCSI initiator is a hardware or software
device running on a computer that accesses
the storage devices on the SAN.
• The other half of the iSCSI equation is the
iSCSI target, which receives SCSI commands
from the initiator and passes them to a
storage device, represented by a logical unit
number (LUN).
Summary
• The Internet Storage Name Service (iSNS) registers
the presence of initiators and targets on a SAN and
responds to queries from iSNS clients.
• Storage Manager for SANs can manage only
storage devices that include support for the
Microsoft Virtual Disk Service.
• The storage device manufacturer must supply a
software component called a VDS hardware
provider, which you install on the computer, that
will manage the device.
Summary
• Storage Explorer is an MMC console that
provides information about SAN resources
and enables administrators to perform a
variety of management tasks.