LVM INTERVIEW QUESTIONS AND ANSWERS
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1..Why we need partition?
Most people have a vague knowledge of what partitions are, since
every operating system has the ability to create or remove them. It may seem
strange that Linux uses more than one partition on the same disk, even when
using the standard installation procedure, so some explanation is called for.
One of the goals of having different partitions is to achieve
higher data security in case of disaster. By dividing the hard disk in
partitions, data can be grouped and separated. When an accident occurs, only
the data in the partition that got the hit will be damaged, while the data on
the other partitions will most likely survive.
2..What
do you mean by LVM?
Logical Volume Manager(LVM ) allows
administrators the flexibility to create logical disks that can be expanded
dynamically as more disk space is required.
3..How
to add the more space in linux?
Adding more disk space for Linux is easy, at
least after the hardware has been properly installed . You format it if
necessary, then create the partitions. and file system as described above, and
add the proper lines to /etc/fstab so that it is mounted automatically
4..How
to save the disk space?
To avoid installing unnecessary programs, Linux
distributions have an option to install only part of the packages they contain.
Compression programs such as gzip or zip will compress individual files or groups of files.
Most modern file systems will allow you to
specify the block size. The block size is chunk size that the file system will
use to read and write data.
5..How
to manage the logical volume with LVM?
To create logical volumes and share these as
block devices. To implement LVMs, we should create the following
A..Physical volumes: This represents the
raw disk space as disk partitions.
When we use partitions, the partition type
should be set to Linux LVM
with an ID of 8E using the fdisk partitioning
tool.
B..Volume groups: This aggregates
physical volumes together so that the disk
space can be consumed to logical volumes.
C..Logical
volumes: This represents the block device that can be shared.
It consumes space that is allocated from
volume groups
6..How
to portioning the disk?
We can
create the partition on the disk
using fdisk command to create .
single extended partition and create logical
partitions therein.
# fdisk /dev/hdb
fdisk
command, will be presented with a menu, you can choose the choices from the
menu
7..How
to create a volume group?
# vgcreate volume_group_name /dev/hda1 /dev/hdb1
Vol group
“vol_group1” successfully created
8..Explain about the LVM in Linux?
The Linux LVM was developed by Heinz
Mauelshagen and released in 1998.
Two versions of Linux LVM are available:
LVM1: The original LVM package released in 1998,
and available in only the 2.4 Linux kernels. It provides only basic Logical
Volume Management features.
LVM2: An updated version of the LVM, available in
the 2.6 Linux kernels. It provides additional features over the standard LVM1
features
9..What
you mean by Snapshots in linux?
The original Linux LVM allows you to copy an
existing logical volume to another device while the logical volume is active.
This feature is called a snapshot. Snapshots are great for backing up important
data that can't be locked due to high availability requirements.
10..What
is Striping and its use in linux?
LVM2 provides is striping. With
striping, a logical volume is created across multiple physical hard drives.
When the Linux LVM writes a file to the logical volume, the data blocks in the
file are spread across the multiple hard drives
Striping helps improve disk performance, as
Linux can write the multiple data blocks for a file to the multiple hard drives
simultaneously, rather than having to wait for a single hard drive to move the
read/write head to different locations.
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