1. Configuring Disk Devices

2. Module 4 – Configuring Disk Devices ♦ Overview This module deals with making partitions using fdisk, implementing RAID and Logical Volume Management. RAID is implemented in Linux systems to provide data redundancy. Logical Volume Management for making the file system management easy ♦ Lessons in this module ► Partitioning Using fdisk ► Implementing RAID ► LVM for Linux

3. Configuring Disk Devices ♦ Introduction Partitioning is done using several utilities. One such utility is fdisk used for performing disk partitions. It is a tool that permits modifying the partitions already made on a hard drive. fdisk is the conventional tool for managing partitions. ♦ Topics Covered in this Lesson ► Partition a disk by using fdisk Lesson 1 – Partitioning using fdisk

4. Configuring Disk Devices Topic 1 – Partition a disk using fdisk ♦ fdisk is the utility used to partition a hard disk. ♦ While partitioning a disk, if fdisk is chosen; the next screen will prompt you to select a drive to partition using fdisk

5. Configuring Disk Devices ♦ list of the fdisk commands List of fdisk commands

6. Configuring Disk Devices ♦ Creating partition can be started by running the command n. Creating Partition

7. Configuring Disk Devices Creating Partition ♦ After running partprobe, run fdisk -1 to check the partitions.

8. Configuring Disk Devices ♦ Running t command will give the range of partition numbers and type whichever partition has to be changed. Hex code (type L to list codes)

9. Configuring Disk Devices Hardware Browser ♦ The details of the partitions are done using the hardware browser. Hardware browser can be seen by typing hwbrowser at a shell prompt. ♦ Otherwise click on Main Menu =>System Tools => Hardware Browser

10. Configuring Disk Devices ♦ Introduction RAID, an acronym for Redundant Array of Independent Disks or Redundant Array of Inexpensive Disks is a method of combining several physical disks to make a virtual disk. It is implemented in the system to increase performance, speed and increase the size and to provide data redundancy. ♦ Topics Covered in this Lesson ► What is RAID? ► Various RAID levels ► Implementation of RAID Lesson 2 – Implementing RAID

11. Configuring Disk Devices Topic 1 - What is RAID? ♦ RAID is an acronym for Redundant Array of Inexpensive Disks or Redundant Array of Independent Disks. ♦ It is called an array of independent disks because even if one disk gets damaged the data can be retrieved from other ♦ The function of the other disks does not get affected. ♦ It is a method of creating one virtual disk by putting together several physical disks.

12. Configuring Disk Devices Topic 2 - Various Levels of RAID ♦ There are various levels of RAID as listed below ► RAID Level 0 ► RAID Level 1 ► RAID Level 2 ► RAID Level 3 ► RAID Level 4 ► RAID Level 5 ► RAID Level 6 ► RAID Level 7 ► RAID Level 0+1 ► RAID Level 1+0

13. Configuring Disk Devices Topic 3 – Implementing RAID ♦ The RAID virtual device should be created using the command mkraid in Enterprise Linux 3 and mdadm in Enterprise Linux 4 ♦ For example, consider Implementing RAID level 5 Contd …

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21. Configuring Disk Devices Corrupting one of the partitions in the RAID device

22. Configuring Disk Devices Adding the partition to the RAID array

23. Configuring Disk Devices Lab Exercise ♦ Exercise Software RAID ♦ Configure the lab by performing the following instructions: ► Create three partitions 100M each and partition type (0*fd) ► Create a software raid with the help of these partitions ► Create one directory test0 and mount your raid partition under this directory ► Give entry in fstab file so that your RAID partition gets mounted at the boot time ► Try to remove one of the three partitions and then add new partition to it

24. Configuring Disk Devices ♦ Introduction Linux has support for Logical Volumes that makes the file system management easy. The Linux Logical Volume Management will introduce an abstraction layer between the physical disk and the file system. ♦ Topics covered in this lesson ► Logical Volume Management or LVM ► Implementing LVM ► Advanced Concepts of LVM Lesson 3 – LVM for Linux

25. Configuring Disk Devices Topic 1 - Logic Volume Management or LVM ♦ LVM stands for logical volume management and is a hard disk drive partitioning scheme ♦ There are two version of LVM for Linux and they are, LVM1 and LVM2 ♦ The following terms are associated with LVM ► Physical Volume (PV) ► Physical Extent (PE) ► Logical Extent (LE) ► Logical Volume (LV) ► Volume Group (VG)

26. Configuring Disk Devices ♦ The steps that have to be performed for implementing LVM are as given below: ► Initializing disks or disk partitions ► Creating a volume group ► Creating a logical volume ► Extending a logical volume Topic 2 – Implementing LVM

27. Configuring Disk Devices ♦ LVM has built-in support for striping and mirroring and can be used with hardware or software RAID to offer configurable, fast and reliable disk storage ♦ LVM Snapshots ► The built-in support for mirroring also offers the concept of snapshots. ► Snapshots of immediate mirrors of logical volume are taken onto free space within the volume group. Topic 3 – Advanced concepts of LVM

28. Configuring Disk Devices Lab Exercise ♦ Exercise Creating Logical Volume Manager ♦ Create LVM by performing the following instructions: ► Create three partitions, each with 100M size and partition type (0*8e) ► Create a volume group name IIHT ► Create logical volume space 40M name data ► Extend your logical volume up to 60M ► Extend your volume group up to next partition ► Remove your LVM configuration

29. Configuring Disk Devices ♦ Summary ► fdisk is a utility to create partitions. Using fdisk, it is possible to create a partition and also delete a partition ► RAID is implemented to copy data and spread blocks of a file across several disk drives. ► LVM provides support to manage file system easily. ♦ Question and Answer Session Conclusion