1. This courseware is copyrighted © 2016 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. 1.3 RAID CompTIA Server+ Certification (Exam SK0-004)

2. Objectives Select an appropriate RAID level for a given storage solution Configure a RAID array using software or hardware 1.3 RAID 27

3. Redundant Array of Independent Disks Performance o Striping Fault tolerance o Mirroring o Parity RAID levels offer different combinations Performance o Reads versus writes o Sequential versus transactional I/O Drive Arrays (RAID) 1.3 RAID 27

4. 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 RAID 28

5. RAID 1 Mirroring 2 disks 50% utilization Tolerates failure of 1 disk Duplexing controllers 1.3 RAID 29

6. 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 RAID 30

7. Requires 4+ disks 50% utilization Can support multiple disk failures (1 per subvolume) RAID 1+0 (RAID 10) 1.3 RAID 31

8. RAID 5+0 (RAID 50) Requires 6+ disks Can support multiple disk failures (1 per subvolume) Can achieve better than 50% utilization o More disks per subvolume increases storage efficiency o Fewer disks per subvolume improves reliability RAID 5+1 1.3 RAID 32

9. Hardware Solutions 1.3 RAID RAID controller o Motherboard support versus expansion card o SAS versus SATA (or parallel SCSI) o RAID level support / proprietary RAID levels Processor Cache Battery-backed cache 32

10. Array Configuration Utilities 1.3 RAID 34

11. Software Solutions Windows Dynamic Disks / Storage Spaces Linux Volume Manager (LVM) “Fake RAID” Just a Bunch of Disks (JBOD) 1.3 RAID 35

12. Level 0 o Total space of all disks in stripe set (assuming all disks are same size) Level 1 / Level 1+0 o 50% Level 5/ Level 6 o (# Drives - 1) * Drive Size for RAID 5 o (# Drives - 2) * Drive Size for RAID 6 Level 5+0 o The array capacity is Drive Size * (# Drives per Set -1) * # Sets o The storage efficiency is (# Drives per Set -1) / # Drives per Set o 2x6-disk (80 GB disks) array gives a capacity of 800 GB (80*(6-1)*2) - 83% efficiency o 3x4-disk array has a capacity of 720 GB - 75% efficiency Calculating Usable Storage 1.3 RAID 36

13. Hot swapping Hot spare Online Capacity Extension Online RAID Level Migration Drive Roaming Controller spanning n-way mirroring Array splitting Enterprise RAID 1.3 RAID 36

14. Same size (and model) Hot-swap and rebuild or reboot server RAID controller upgrade / replacement Firmware updates o Controller firmware o Disk firmware Installing Drives in a RAID Array 1.3 RAID 38

15. Review Select an appropriate RAID level for a given storage solution Configure a RAID array using software or hardware 1.3 RAID 39