Archive for the ‘RAID and LVM’ Category

We have already learnt how to increase the size of lvm using lvextend command in linux.But Now here in this tutorial we will learn the reverse process i.e how to Reduce the lvm size in linux and we will do this in few simple steps.So this is basically an example lab showing how to reduce size of lvm in linux. (more…)

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If you are working as a Linux System Admin then resizing the file system size is an important task for you and you must know that.Here in this tutorial we are going to learn how to increase or extend lvm partition size.As we all know LVM provides us the facility to increase or reduce the of partition.

So here we will learn to increase lvm size using lvextend command.but before that we will create lvm first and mount it so that it is ready for use.

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 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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