Archive for the ‘RAID and LVM’ Category

 In this tutorial we will learn how to manually fail a device used in raid and how to add a new to device to existing raid. we will also learn how to use spare device and how to stop and remove software raid completely from our linux machine. But before we starting removing any devices from existing  raid device first check the built topology of created raid.check the number of disk and name of disk used in raid as active device and find out the device name used as spare device using below linux command line tools. (more…)

This tutorial is all about software raid-1 creation in linux.We will learn how to configure software raid-1 in linux having spare devices.In this lab we are going to use RedHat Enterprise Linux 5 to configure software raid-1 with spare device.We use spare device as a reserved disk which is used only when any of disk used in raid-1 failed.

As we know RAID-1 needs minimum of two disk and when any of disk among those two failed or crashes spare device replaces itself with that failed device or disk.

raid1 configuration in linux

 

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This tutorial is all about how to configure software raid-0  in RedHat Enterprise Linux.Even if you are new to Linux you can easily configure RAID-0 by reading this article.I have written raid-0 creation notes step wise from begining to end.In this article instead of two hard drive i have used two different partitions to show you how to create and configure software RAID-0 in Linux.RAID-0 is also known as No RAID because it doesn’t provides redundancy.To create RAID-0 array minimum device/partitions required is two.RAID-0 write data on different hard drives and hence increase the read-write speed.RAID-0 is needed only where we needs performance but no redundancy. (more…)

This tutorial is all about LVM SNAPSHOT .Please Don’t think that it is a substitute of media backup,no it’s not.LVM Snapshot features provides the ability to  create virtual images of device at a particular instant without causing any service interruption. so you can also say that Snapshot copies of a file system are just a virtual copy and not a media backup for file system.snapshot features requires a minimal amount of storage.3-5% of the original capacity is enough to store and maintain snapshot data.

Now what happen when change is made to original device after a snapshot is taken?

Answer is snapshot features make a copy of the changed data area as it was prior to the changes so that it can reconstruct the state of the device.

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In the world of computer  data is more important and with increase in internet users it’s increasing very fast and hence now storing data is most challenging task.Now it is not good to store your data on single drive when you know your data is important,because in case of disk failure your data will loss and it will be a huge disaster.So in place of storing data on a single disk it will be intelligent decesion to store your data on multiple disk such that if one disk fails your data is still safe on second disk.

There are two technology or you can say there are two methods commonly used to store data on multiple disk:

(1)One is to strore data on multiple disk through RAID and

(2)other is through LVM.

Since LVM provides us more flexblity  in handling disk and managing data,so most of us prefer configuring LVM.

In This article i have mentioned how to create and configure mirrored logical volume.here we learn the fundamental concept of LVM Mirroring and also learn to create,manage ad maintain LVM mirror in Linux in few simple steps. (more…)