RAID (Redundant Array of Independent Disks) is a technology that combines multiple disk drives into a single logical unit to improve data reliability, increase input/output performance, or achieve both. There are different RAID levels serving different purposes - RAID 0 stripes data across disks for performance; RAID 1 mirrors data across disks for redundancy; RAID 5 uses block-level striping with distributed parity for both performance and fault tolerance. The document then provides commands to implement a RAID 5 array using 3 disks on a RHEL system and test failure recovery functionality.

1. RAID & It’s
Levels
SYSTEM AND NETWORK ADMINISTRATION

2. “The unsung heroes weaving the web of
connectivity, where every click, every
connection, is their masterpiece”
- SHERRY

3. RAID
TECHNOLOGY
REDUNDANT ARRAY OF INDEPENDENT DISKS

4. Introduction to RAID
 RAID is a technology that
significantly enhances data storage
and reliability. Let's explore its
various aspects.

5.  Redundant Array of Independent Disks is
a storage technology that combines
multiple disk drives into a single logical
unit. The main goals of RAID are to
improve data reliability, increase
input/output performance, or achieve
both simultaneously.

6. RAID Levels
 There are several RAID levels, each
serving different purposes.

7. RAID 0 (Striping for Performance)
 RAID 0 stripes data
across multiple disks,
enhancing
performance. However,
it doesn't provide
redundancy, so if one
drive fails, data is lost.

8. RAID1 (Mirroring for Redundancy)
 RAID 1 mirrors data
across two disks,
offering redundancy.
If one drive fails,
data is still
accessible from the
other drive

9. RAID 1 0 (Mirroring & Stripping)
 RAID 10 combines
the mirroring of
RAID 1 and the
striping of RAID 0. It
provides high
performance and
fault tolerance.

10. RAID 5 (Striping with Parity)
 RAID 5 uses block-
level striping with
distributed parity. It
offers both
performance and fault
tolerance. If one drive
fails, the system can
rebuild the lost data.

11. RAID 6 (Dual Parity)
 RAID 6 uses dual
parity for fault
tolerance. It can
withstand the
failure of two
drives without
losing data.

12. LET’S GO FOR
IMPLEMENTATION
OPEN THE TERMINAL IN YOUR RHEL.

13. COMMANDS:
Implementation
yum install –y mdadm // install setup for raid
 rpm –qa |grep mdadm // check if setup installed
 lsblk //detail partitions of disks
 mdadm -C /dev/md0 –l 5 –n3 /dev/sdb /dev/sdc /dev/sdd // create raid array
 mdadm –D /dev/md0 // detail array (raid)
 cat /proc/mdstat // details of array
 mdadm /dev/md0 –f /dev/sdd // fail disk sdd
 mdadm -D /dev/md0 // details of array
 mdadm /dev/md0 –r /dev/sdd // remove sdd disk
 mdadm /dev/md0 –a /dev/sdd // re add the disk sdd
 mdadm -vs /dev/md0 // remove all the disk from array
 mdadm -remove /dev/md0 // remove raid from system