Transcript 1.3 Storage and RAID - Glendale Community College

CompTIA Server+
Certification
1.3 Storage and RAID
This courseware is copyrighted © 2011 gtslearning. No part of this courseware or any training material supplied by gtslearning International Limited to accompany
the courseware may be copied, photocopied, reproduced, or re-used in any form or by any means without permission in writing from a director of gtslearning
International Limited. Violation of these laws will lead to prosecution. All trademarks, service marks, products, or services are trademarks or registered trademarks
of their respective holders and are acknowledged by the publisher.
All gtslearning products are supplied on the basis of a single copy of a course per student. Additional resources that may be made available from gtslearning may
only be used in conjunction with courses sold by gtslearning. No material changes to these resources are permitted without express written permission by a director
of gtslearning. These resources may not be used in conjunction with content from any other supplier.
If you suspect that this course has been copied or distributed illegally, please telephone or email gtslearning.
Objectives
• Describe the features and
performance characteristics of
server-class hard disks and solid
state drives
• Describe features of the SCSI
interface and know how to
configure devices correctly
• Describe features of the SATA and
SAS interfaces and know how to
configure devices correctly
• Select an appropriate RAID level
for a given storage solution
• Configure a RAID array
1.3 Storage and RAID
Slide 2
Hard Drives
• HDD
– SCSI / SAS / SATA
– LFF and SFF
• SDD
• Enclosure /
backplane
1.3 Storage and RAID
Slide 3
The SCSI Interface
• Parallel SCSI
– SCSI-1
– SCSI-2
• Fast / wide SCSI
• Active termination
– SCSI-3
• UltraSCSI
• Firewire
• Fiber Channel / iSCSI
• SAS
1.3 Storage and RAID
Slide 4
Parallel SCSI Configuration
• HBA
• Internal and external
devices
• Signaling (SE / HVD /
LVD)
• Connectors
• Termination
• IDs and LUNs
• Drivers / config utility
1.3 Storage and RAID
Slide 5
Serial Attached SCSI
• Standard for new
enterprise servers
• 3 Gbps or 6 Gbps
• Bus can host SATA
devices
• Connectors
1.3 Storage and RAID
Slide 6
Serial ATA
• Desktop market /
cheaper servers
• 1.5 / 3 / 6 Gbps
• eSATA
1.3 Storage and RAID
Slide 7
Drive Arrays (RAID)
• Redundant Array of Independent Disks
• Performance
– Striping
• Fault tolerance
– Mirroring
– Parity
• RAID levels offer different combinations
• Performance
– Reads versus writes
– Sequential versus transactional I/O
1.3 Storage and RAID
Slide 8
RAID 0
• Data stored in blocks (stripe
size) across multiple drives
(stripe width)
• Improves read and write
performance
• Volume size is capacity of all
disks (assuming disks are
equal capacity)
• No fault tolerance
• Specialist applications only
(where complete loss of data
is tolerable)
1.3 Storage and RAID
Slide 9
RAID 1
• Mirroring
• 2 disks
• 50% utilization
• Tolerates failure of 1
disk
• Duplexing
controllers
1.3 Storage and RAID
Slide 10
RAID 5
• RAID 3 (Striping with
parity disk)
• RAID 5 (distributed
parity)
• Minimum 3 disks
• Tolerates failure of 1
disk
• RAID 6 supports 2
disk failures
1.3 Storage and RAID
Slide 11
RAID 1+0 (RAID 10)
• Requires 4+ disks
• 50% utilization
• Can support multiple disk failures (1 per
subvolume)
1.3 Storage and RAID
Slide 12
RAID 5+0 (RAID 50)
• Requires 6+ disks
• Can support multiple
disk failures (1 per
subvolume)
• Can achieve better
than 50% utilization
– More disks per
subvolume increases
storage efficiency
– Fewer disks per
subvolume improves
reliability
1.3 Storage and RAID
Slide 13
Calculating Usable Storage
• Level 0
– Total space of all disks in stripe set (assuming all disks are same size)
• Level 1 / Level 1+0
– 50%
• Level 5/ Level 6
– (# Drives - 1) * Drive Size for RAID 5
– (# Drives - 2) * Drive Size for RAID 6
• Level 5+0
– The array capacity is Drive Size * (# Drives per Set -1) * # Sets
– The storage efficiency is (# Drives per Set -1) / # Drives per Set
– 2x6-disk (80 GB disks) array gives a capacity of 800 GB (80*(6-1)*2)
- 83% efficiency
– 3x4-disk array has a capacity of 720 GB - 75% efficiency
1.3 Storage and RAID
Slide 14
Implementing RAID
• Hardware
• Fake RAID
• Software
1.3 Storage and RAID
Slide 15
Enterprise RAID
• Hot swapping
• Hot spare
• Online Capacity Extension
• Online RAID Level Migration
• Drive Roaming
• Controller spanning
• n-way mirroring
• Array splitting
1.3 Storage and RAID
Slide 16
Review
• Describe the features and
performance characteristics of
server-class hard disks and solid
state drives
• Describe features of the SCSI
interface and know how to
configure devices correctly
• Describe features of the SATA and
SAS interfaces and know how to
configure devices correctly
• Select an appropriate RAID level
for a given storage solution
• Configure a RAID array
1.3 Storage and RAID
Slide 17
Labs
• Lab 1 Configuring RAID
1.3 Storage and RAID
Slide 18