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What are logical volumes?

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26.What are logical volumes?
Ans.
1. Logical volume manager (LVM) enables you to be much more flexible with your disk usage than you can be with conventional old-style file partitions.

 2. Normally if we create a partition we have to keep the partition at that size indefinitely.

 3. For example, if our system logs have grown immensely, and we ran out of space on ‘/var’ partition, increasing a partition size without LVM is a big pain.

 4. With LVM we can add another disk, create a physical volume to the volume group that contains the /var partition.

 5. Then we can use the LVM file system resizing tool to increase the file system size to match the new partition size.

 6. We can use a file system creation tool such as fdisk to create a file system on logical volume.

 7. Basic syntax for using ‘lvm’ command is :
lvm<command> file
We can obtain complete listing of commands by entering ‘lvm help’ at command prompt.

 8. To get a list of logical volumes on your system, enter ‘lvm lvdisply’ in terminal prompt.

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