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20140813-2 选题
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How to Extend/Reduce LVM’s (Logical Volume Management) in Linux – Part II
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================================================================================
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Previously we have seen how to create a flexible disk storage using LVM. Here, we are going to see how to extend volume group, extend and reduce a logical volume. Here we can reduce or extend the partitions in Logical volume management (LVM) also called as flexible volume file-system.
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![Extend/Reduce LVMs in Linux](http://www.tecmint.com/wp-content/uploads/2014/08/LVM_extend.jpg)
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### Requirements ###
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- [Create Flexible Disk Storage with LVM – Part I][1]
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注:两篇都翻译完了的话,发布的时候将这个链接做成发布的中文的文章地址
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#### When do we need to reduce volume? ####
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May be we need to create a separate partition for any other use or we need to expand the size of any low space partition, if so we can reduce the large size partition and we can expand the low space partition very easily by the following simple easy steps.
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#### My Server Setup – Requirements ####
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- Operating System – CentOS 6.5 with LVM Installation
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- Server IP – 192.168.0.200
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### How to Extend Volume Group and Reduce Logical Volume ###
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#### Logical Volume Extending ####
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Currently, we have One PV, VG and 2 LV. Let’s list them one by one using following commands.
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# pvs
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# vgs
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# lvs
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![Logical Volume Extending](http://www.tecmint.com/wp-content/uploads/2014/08/Logical-Volume-Extending.jpg)
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Logical Volume Extending
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There are no free space available in Physical Volume and Volume group. So, now we can’t extend the lvm size, for extending we need to add one physical volume (**PV**), and then we have to extend the volume group by extending the **vg**. We will get enough space to extend the Logical volume size. So first we are going to add one physical volume.
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For adding a new **PV** we have to use fdisk to create the LVM partition.
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# fdisk -cu /dev/sda
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- To Create new partition Press **n**.
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- Choose primary partition use **p**.
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- Choose which number of partition to be selected to create the primary partition.
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- Press **1** if any other disk available.
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- Change the type using **t**.
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- Type **8e** to change the partition type to Linux LVM.
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- Use **p** to print the create partition ( here we have not used the option).
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- Press **w** to write the changes.
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Restart the system once completed.
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![Create LVM Partition](http://www.tecmint.com/wp-content/uploads/2014/08/Create-LVM-Partition.jpg)
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Create LVM Partition
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List and check the partition we have created using fdisk.
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# fdisk -l /dev/sda
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![Verify LVM Partition](http://www.tecmint.com/wp-content/uploads/2014/08/Verify-LVM-Partition.jpg)
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Verify LVM Partition
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Next, create new **PV** (Physical Volume) using following command.
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# pvcreate /dev/sda1
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Verify the pv using below command.
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# pvs
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![Create Physical Volume](http://www.tecmint.com/wp-content/uploads/2014/08/Create-Physical-Volume.jpg)
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Create Physical Volume
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#### Extending Volume Group ####
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Add this pv to **vg_tecmint** vg to extend the size of a volume group to get more space for expanding **lv**.
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# vgextend vg_tecmint /dev/sda1
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Let us check the size of a Volume Group now using.
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# vgs
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![Extend Volume Group](http://www.tecmint.com/wp-content/uploads/2014/08/Extend-Volume-Group.jpg)
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Extend Volume Group
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We can even see which **PV** are used to create particular Volume group using.
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# pvscan
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![Check Volume Group](http://www.tecmint.com/wp-content/uploads/2014/08/Check-Volume-Group.jpg)
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Check Volume Group
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Here, we can see which Volume groups are under Which Physical Volumes. We have just added one pv and its totally free. Let us see the size of each logical volume we have currently before expanding it.
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![Check All Logical Volume](http://www.tecmint.com/wp-content/uploads/2014/08/Check-Each-Logical-Volume.jpg)
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Check All Logical Volume
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- LogVol00 defined for Swap.
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- LogVol01 defined for /.
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- Now we have 16.50 GB size for / (root).
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- Currently there are 4226 Physical Extend (PE) available.
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Now we are going to expand the / partition **LogVol01**. After expanding we can list out the size as above for confirmation. We can extend using GB or PE as I have explained it in LVM PART-I, here I’m using PE to extend.
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For getting the available Physical Extend size run.
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# vgdisplay
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![Check Available Physical Size](http://www.tecmint.com/wp-content/uploads/2014/08/Check-Available-Physical-Extend.jpg)
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Check Available Physical Size
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There are **4607** free PE available = **18GB** Free space available. So we can expand our logical volume up-to **18GB** more. Let us use the PE size to extend.
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# lvextend -l +4607 /dev/vg_tecmint/LogVol01
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Use **+** to add the more space. After Extending, we need to re-size the file-system using.
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# resize2fs /dev/vg_tecmint/LogVol01
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![Expand Logical Volume](http://www.tecmint.com/wp-content/uploads/2014/08/Expand-Logical-Volume.jpg)
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Expand Logical Volume
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- Command used to extend the logical volume using Physical extends.
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- Here we can see it is extended to 34GB from 16.51GB.
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- Re-size the file system, If the file-system is mounted and currently under use.
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- For extending Logical volumes we don’t need to unmount the file-system.
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Now let’s see the size of re-sized logical volume using.
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# lvdisplay
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![Resize Logical Volume](http://www.tecmint.com/wp-content/uploads/2014/08/Resize-Logical-Volume.jpg)
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Resize Logical Volume
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- LogVol01 defined for / extended volume.
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- After extending there is 34.50GB from 16.50GB.
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- Current extends, Before extending there was 4226, we have added 4607 extends to expand so totally there are 8833.
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Now if we check the vg available Free PE it will be 0.
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# vgdisplay
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See the result of extending.
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# pvs
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# vgs
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# lvs
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![Verify Resize Partition](http://www.tecmint.com/wp-content/uploads/2014/08/Verify-Resize-Partition.jpg)
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Verify Resize Partition
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- New Physical Volume added.
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- Volume group vg_tecmint extended from 17.51GB to 35.50GB.
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- Logical volume LogVol01 extended from 16.51GB to 34.50GB.
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Here we have completed the process of extending volume group and logical volumes. Let us move towards some interesting part in Logical volume management.
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#### Reducing Logical Volume (LVM) ####
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Here we are going to see how to reduce the Logical Volumes. Everyone say its critical and may end up with disaster while we reduce the lvm. Reducing lvm is really interesting than any other part in Logical volume management.
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- Before starting, it is always good to backup the data, so that it will not be a headache if something goes wrong.
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- To Reduce a logical volume there are 5 steps needed to be done very carefully.
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- While extending a volume we can extend it while the volume under mount status (online), but for reduce we must need to unmount the file system before reducing.
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Let’s wee what are the 5 steps below.
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- unmount the file system for reducing.
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- Check the file system after unmount.
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- Reduce the file system.
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- Reduce the Logical Volume size than Current size.
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- Recheck the file system for error.
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- Remount the file-system back to stage.
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For demonstration, I have created separate volume group and logical volume. Here, I’m going to reduce the logical volume **tecmint_reduce_test**. Now its 18GB in size. We need to reduce it to **10GB** without data-loss. That means we need to reduce **8GB** out of **18GB**. Already there is **4GB** data in the volume.
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18GB ---> 10GB
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While reducing size, we need to reduce only 8GB so it will roundup to 10GB after the reduce.
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# lvs
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![Reduce Logical Volume](http://www.tecmint.com/wp-content/uploads/2014/08/Reduce-Logical-Volume.jpg)
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Reduce Logical Volume
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Here we can see the file-system information.
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# df -h
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![Check File System Size](http://www.tecmint.com/wp-content/uploads/2014/08/Check-File-System-Size.jpg)
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Check File System Size
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- The size of the Volume is 18GB.
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- Already it used upto 3.9GB.
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- Available Space is 13GB.
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First unmount the mount point.
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# umount -v /mnt/tecmint_reduce_test/
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![Unmount Parition](http://www.tecmint.com/wp-content/uploads/2014/08/Unmount-Parition.jpg)
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Unmount Parition
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Then check for the file-system error using following command.
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# e2fsck -ff /dev/vg_tecmint_extra/tecmint_reduce_test
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![Scan Parition for Errors](http://www.tecmint.com/wp-content/uploads/2014/08/Scan-Parition-for-Errors.jpg)
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Scan Parition for Errors
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**Note**: Must pass in every 5 steps of file-system check if not there might be some issue with your file-system.
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Next, reduce the file-system.
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# resize2fs /dev/vg_tecmint_extra/tecmint_reduce_test 8GB
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![Reduce File System](http://www.tecmint.com/wp-content/uploads/2014/08/Reduce-File-System.jpg)
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Reduce File System
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Reduce the Logical volume using GB size.
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# lvreduce -L -8G /dev/vg_tecmint_extra/tecmint_reduce_test
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![Reduce Logical Partition](http://www.tecmint.com/wp-content/uploads/2014/08/Reduce-Logical-Volume-Partition.jpg)
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Reduce Logical Partition
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To Reduce Logical volume using PE Size we need to Know the size of default PE size and total PE size of a Volume Group to put a small calculation for accurate Reduce size.
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# lvdisplay vg_tecmint_extra
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Here we need to do a little calculation to get the PE size of 10GB using bc command.
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1024MB x 10GB = 10240MB or 10GB
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10240MB / 4PE = 2048PE
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Press **CRTL+D** to exit from BC.
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![Calculate PE Size](http://www.tecmint.com/wp-content/uploads/2014/08/bc-command.jpg)
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Calculate PE Size
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Reduce the size using PE.
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# lvreduce -l -2048 /dev/vg_tecmint_extra/tecmint_reduce_test
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![Reduce Size Using PE](http://www.tecmint.com/wp-content/uploads/2014/08/Reduce-Size-Using-PE.jpg)
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Reduce Size Using PE
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Re-size the file-system back, In this step if there is any error that means we have messed-up our file-system.
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# resize2fs /dev/vg_tecmint_extra/tecmint_reduce_test
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![Resize File System](http://www.tecmint.com/wp-content/uploads/2014/08/Resize-File-System.jpg)
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Mount the file-system back to same point.
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# mount /dev/vg_tecmint_extra/tecmint_reduce_test /mnt/tecmint_reduce_test/
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![Mount File System](http://www.tecmint.com/wp-content/uploads/2014/08/Mount-File-System.jpg)
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Mount File System
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Check the size of partition and files.
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# lvdisplay vg_tecmint_extra
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Here we can see the final result as the logical volume was reduced to 10GB size.
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![Verify Logical Volume Size](http://www.tecmint.com/wp-content/uploads/2014/08/Verify-Logical-Volume-Size.jpg)
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In this article, we have seen how to extend the volume group, logical volume and reduce the logical volume. In the next part (Part III), we will see how to take a Snapshot of logical volume and restore it to earlier stage.
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--------------------------------------------------------------------------------
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via: http://www.tecmint.com/extend-and-reduce-lvms-in-linux/
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作者:[Babin Lonston][a]
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译者:[译者ID](https://github.com/译者ID)
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校对:[校对者ID](https://github.com/校对者ID)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译,[Linux中国](http://linux.cn/) 荣誉推出
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[a]:http://www.tecmint.com/author/babinlonston/
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[1]:http://www.tecmint.com/create-lvm-storage-in-linux/
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sources/tech/20140813 How to remove file metadata on Linux.md
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How to remove file metadata on Linux
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================================================================================
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A typical data file often has associated "metadata" which is descriptive information about the file, represented in the form of a set of name-value pairs. Common metadata include creator's name, tools used to generate the file, file creation/update date, location of creation, editing history, etc. EXIF (images), RDF (web resources), DOI (digital documents) are some of popular metadata standards.
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While metadata has its own merits in data management fields, it can actually affect your privacy [adversely][1]. EXIF data in photo images can reveal personally identifiable information such as your camera model, GPS coordinate of shooting, your favorite photo editor software, etc. Metadata in documents and spreadsheets contain author/affiliation information and other editing history. Not to be paranoid, but metadata gathering tools such as [metagoofil][2] are often exploited during information gathering stage as part of penetration testing.
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For those of you who want to strip any personalizing metadata from any shared data, there are ways to remove metadata from data files. You can use existing document or image editor software which typically have built-in metadata editing capability. In this tutorial, let me introduce a nice standalone **metadata cleaner tool** which is developed for a single goal: **anonymize all metadata for your privacy**.
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[MAT][3] (Metadata Anonymisation Toolkit) is a dedicated metadata cleaner written in Python. It was developed under the umbrella of the Tor project, and comes standard on [Tails][4], privacy-enhanced live OS.
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Compared to other tools such as [exiftool][5] which can write to only a limited number of file types, MAT can eliminate metadata from all kinds of files: images (png, jpg), documents (odt, docx, pptx, xlsx, pdf), archives (tar, tar.bz2), audio (mp3, ogg, flac), etc.
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### Install MAT on Linux ###
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On Debian-based systems (Ubuntu or Linux Mint), MAT comes packaged, so installation is straightforward:
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$ sudo apt-get install mat
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On Fedora, MAT does not come as a pre-built package, so you need to build it from the source. Here is how I built MAT on Fedora (with some limited success; see the bottom of the tutorial):
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$ sudo yum install python-devel intltool python-pdfrw perl-Image-ExifTool python-mutagen
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$ sudo pip install hachoir-core hachoir-parser
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$ wget https://mat.boum.org/files/mat-0.5.tar.xz
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$ tar xf mat-0.5.tar.xz
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$ cd mat-0.5
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$ python setup.py install
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### Anonymize Metadata with MAT-GUI ###
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Once installed, MAT can be accessible via GUI as well as from the command line. To launch MAT's GUI, simply type:
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$ mat-gui
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Let's clean up a sample document file (e.g., private.odt) which has the following metadata embedded.
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![](https://farm6.staticflickr.com/5588/14694815240_22eced1f94_z.jpg)
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To add the file to MAT for cleanup, click on "Add" icon. Once the file is loaded, click on "Check" icon to scan for any hidden metadata information.
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![](https://farm4.staticflickr.com/3874/14694958067_00694d9d1f_z.jpg)
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Once any metadata is detected by MAT, "State" will be marked as "Dirty". You can double click the file to see detected metadata.
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![](https://farm4.staticflickr.com/3861/14694815160_cda63bb8d8_z.jpg)
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To clean up metadata from the file, click on "Clean" icon. MAT will automatically empty all private metadata fields from the file.
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![](https://farm6.staticflickr.com/5554/14694815220_40918f680f_z.jpg)
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The cleaned up state is without any personally identifiable traces:
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![](https://farm6.staticflickr.com/5591/14881486215_83808b6aaf_z.jpg)
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### Anonymize Metadata from the Command Line ###
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As mentioned before, another way to invoke MAT is from the command line, and for that, use mat command.
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To check for any sensitive metadata, first go to the directory where your files are located, and then run:
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$ mat -c .
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It will scan all files in the current directory and its sub directories, and report their state (clean or unclean).
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![](https://farm6.staticflickr.com/5564/14878449991_cf9d605e6d_o.png)
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You can check actual metadata detected by using '-d' option:
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$ mat -d <input_file>
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![](https://farm6.staticflickr.com/5558/14901361173_0e587329f5_z.jpg)
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If you don't supply any option with mat command, the default action is to remove metadata from files. If you want to keep a backup of original files during cleanup, use '-b' option. The following command cleans up all files, and stores original files as '*.bak" files.
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$ mat -b .
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![](https://farm6.staticflickr.com/5591/14694850169_1cf7562657_z.jpg)
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To see a list of all supported file types, run:
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$ mat -l
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![](https://farm6.staticflickr.com/5588/14901361153_e59ab7b684_z.jpg)
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### Troubleshooting ###
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Currently I have the following issue with a compiled version of MAT on Fedora. When I attempt to clean up archive/document files (e.g., *.gz, *.odt, *.docx) on Fedora, MAT fails with the following error. If you know how to fix this problem, let me know in the comment.
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File "/usr/lib64/python2.7/zipfile.py", line 305, in __init__
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raise ValueError('ZIP does not support timestamps before 1980')
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ValueError: ZIP does not support timestamps before 1980
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### Conclusion ###
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MAT is a simple, yet extremely useful tool to prevent any inadvertent privacy leaks from metadata. Note that it is still your responsibility to anonymize file content, if necessary. All MAT does is to eliminate metadata associated with your files, but does nothing with the files themselves. In short, MAT can be a life saver as it can handle most common metadata removal, but you shouldn't rely solely on it to guarantee your privacy.
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--------------------------------------------------------------------------------
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via: http://xmodulo.com/2014/08/remove-file-metadata-linux.html
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作者:[Dan Nanni][a]
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译者:[译者ID](https://github.com/译者ID)
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校对:[校对者ID](https://github.com/校对者ID)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译,[Linux中国](http://linux.cn/) 荣誉推出
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[a]:http://xmodulo.com/author/nanni
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[1]:http://www.theguardian.com/world/2013/sep/30/nsa-americans-metadata-year-documents
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[2]:http://code.google.com/p/metagoofil/
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[3]:https://mat.boum.org/
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[4]:https://tails.boum.org/
|
||||
[5]:http://xmodulo.com/2013/08/view-or-edit-pdf-and-image-metadata-from-command-line-on-linux.html
|
@ -0,0 +1,354 @@
|
||||
Setup Flexible Disk Storage with Logical Volume Management (LVM) in Linux – PART 1
|
||||
================================================================================
|
||||
**Logical Volume Management (LVM)** makes it easier to manage disk space. If a file system needs more space, it can be added to its logical volumes from the free spaces in its volume group and the file system can be re-sized as we wish. If a disk starts to fail, replacement disk can be registered as a physical volume with the volume group and the logical volumes extents can be migrated to the new disk without data loss.
|
||||
|
||||
![Create LVM Storage in Linux](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage.jpg)
|
||||
Create LVM Storage in Linux
|
||||
|
||||
In a modern world every Server needs more space day by day for that we need to expand depending on our needs. Logical volumes can be use in RAID, SAN. A Physical Disk will be grouped to create a volume Group. Inside volume group we need to slice the space to create Logical volumes. While using logical volumes we can extend across multiple disks, logical volumes or reduce logical volumes in size with some commands without reformatting and re-partitioning the current disk. Volumes can stripes data across multiple disks this can increase the I/O stats.
|
||||
|
||||
### LVM Features ###
|
||||
|
||||
- It is flexible to expand the space at any time.
|
||||
- Any file systems can be installed and handle.
|
||||
- Migration can be used to recover faulty disk.
|
||||
- Restore the file system using Snapshot features to earlier stage. etc…
|
||||
|
||||
#### My Server Setup – Requirements ####
|
||||
|
||||
- Operating System – CentOS 6.5 with LVM Installation
|
||||
- Server IP – 192.168.0.200
|
||||
|
||||
### Creating LVM Disk Storage in Linux ###
|
||||
|
||||
**1. **We’ve used CentOS 6.5 Operating system using LVM in a Virtual Disk (VDA). Here we can see the Physical Volume (PV), Volume Group (VG), Logical Volume (LV) by using following command.
|
||||
|
||||
# pvs
|
||||
# vgs
|
||||
# lvs
|
||||
|
||||
![Check Physical Volumes](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-03.jpg)
|
||||
Check Physical Volumes
|
||||
|
||||
Here, is the description of each parameters shown in above screenshot.
|
||||
|
||||
- Physical Disk Size (PV Size)
|
||||
- Disk which used was Virtual Disk vda.
|
||||
- Volume Group Size (VG Size)
|
||||
- Volume Group name (vg_tecmint)
|
||||
- Logical Volume name (LogVol00, LogVol01)
|
||||
- LogVol00 Assigned for sawp with 1GB Size
|
||||
- LogVol01 Assigned for / with 16.5GB
|
||||
|
||||
So, from here we come to know that there is not enough free space in VDA disk.
|
||||
|
||||
**2. **For Creating a **New Volume Group**, we need to add Additional **3 hard disks** in this server. It is not Compulsory to use 3 Drives just 1 is Enough to create a new **VG** and **LV** inside that vg, I am adding more here for demonstration purpose and for more feature command explanations.
|
||||
|
||||
Following are the disks I have added additionally.
|
||||
|
||||
sda, sdb, sdc
|
||||
|
||||
----------
|
||||
|
||||
# fdisk -l
|
||||
|
||||
![Verify Added Disks](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-04.jpg)
|
||||
Verify Added Disks
|
||||
|
||||
- Default Disk using for Operating system (Centos6.5).
|
||||
- Partitions defined in default Disk (vda1 = swap), (vda2 = /).
|
||||
- Additionally added Disks are mentioned as Disk1, Disk2, Disk3.
|
||||
|
||||
Each and every Disks are 20 GB in Size. Default PE Size of a Volume Group is 4 MB, Volume group what we are using in this server is configured using default PE.
|
||||
|
||||
![Volume Group Display](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-05.jpg)
|
||||
Volume Group Display
|
||||
|
||||
- **VG Name** – A Volume Group name.
|
||||
- **Format** – LVM Architecture Used LVM2.
|
||||
- **VG Access** – Volume Group is in Read and Write and ready to use.
|
||||
- **VG Status** – Volume Group can be re-sized, We can Expand more if we need to add more space.
|
||||
- **Cur LV** – Currently there was 2 Logical volumes in this Volume Group.
|
||||
- **CurPV and Act PV** – Currently Using Physical Disk was 1 (vda), And its active, so what we can use this volume group.
|
||||
- **PE Size** – Physical Extends, Size for a disk can be defined using PE or GB size, 4MB is the Default PE size of LVM. For example, if we need to create 5 GB size of logical volume we can use sum of 1280 PE, Don’t you understand what I’m saying ?.
|
||||
|
||||
Here the Explanation –> 1024MB = 1GB, if so 1024MB x 5 = 5120PE = 5GB, Now Divide the 5120/4 = 1280, 4 is the Default PE Size.
|
||||
|
||||
- Total PE – This Volume Group have.
|
||||
- Alloc PE – Total PE Used, full PE already Used, 4482 x 4PE = 17928.
|
||||
- Free PE – Here it’s already used so there was no free PE.
|
||||
|
||||
**3. **Only vda used, Currently Centos Installed **/boot, /, swap,** in vda physical disk using lvm there were no space remaining in this disk.
|
||||
|
||||
# df -TH
|
||||
|
||||
![Check the Disk Space](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-06.jpg)
|
||||
Check the Disk Space
|
||||
|
||||
Above image shows the mount Point we are using **18GB** fully used for root, so there is no free space available.
|
||||
|
||||
**4. **So let’s, create new physical volume (**pv**), Volume Group (**vg**) in the name of **tecmint_add_vg** and create Logical Volumes (**lv**) in it, Here we can create 4 Logical Volumes in the name of **tecmint_documents**, **tecmint_manager** and **tecmint_public**.
|
||||
|
||||
We can extend the Volume Group of currently using VG to get more space. But here, what we are going to do is to Create new Volume Group and play around it, later we can see how to extend the file systems Volume group which is currently in use.
|
||||
|
||||
Before using a new Disk we need to partition the disk using fdisk.
|
||||
|
||||
# fdisk -cu /dev/sda
|
||||
|
||||
- **c** – Switch off DOS-compatible mode it is Recommend to include this Option.
|
||||
- **u** – While listing the partition tables it will give us in sector instead of cylinder.
|
||||
|
||||
![Create New Physical Partitions](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-07.jpg)
|
||||
Create New Physical Partitions
|
||||
|
||||
Next, follow the below steps to create new partition.
|
||||
|
||||
- Choose **n** to create new.
|
||||
- Choose **p** to create a primary partition.
|
||||
- Choose which number of partition we need to create.
|
||||
- Press **Enter** twice to use the full space of the Disk.
|
||||
- We need to change the type of newly created partition type **t**.
|
||||
- Which number of partition need to change, choose the number which we created its **1**.
|
||||
- Here we need to change the type, we need to create LVM so we going to use the type code of LVM as 8e, if we do not know the type code Press **L** to list all type codes.
|
||||
- Print the Partition what we created to just confirm.
|
||||
- Here we can see the ID as 8e LINUX LVM.
|
||||
- Write the changes and exit fdisk.
|
||||
|
||||
Do the above steps for other 2 disks sdb and sdc to create new partitions. Then Restart the machine to verify the partition table using fdisk command.
|
||||
|
||||
# fdisk -l
|
||||
|
||||
![Verify Partition Table](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-08.jpg)
|
||||
Verify Partition Table
|
||||
|
||||
### Creating Physical Volumes ###
|
||||
|
||||
**5. **Now, it’s time to create Physical Volumes using all 3 disks. Here, I have listed the physical disk using pvs command, only one default **pvs** is now listed.
|
||||
|
||||
# pvs
|
||||
|
||||
Then create the new physical disks using command.
|
||||
|
||||
# pvcreate /dev/sda1 /dev/sdb1 /dev/sdc1
|
||||
|
||||
Once again list the disk to see the newly created Physical disks.
|
||||
|
||||
# pvs
|
||||
|
||||
![Create Physical Volumes](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-09.jpg)
|
||||
Create Physical Volumes
|
||||
|
||||
### Creating Volume Groups ###
|
||||
|
||||
**6. **Create Volume Group in the name of **tecmint_add_vg** using available free PV Create using PE size 32. To Display the current volume groups, we can see there is one volume group with 1 PV using.
|
||||
|
||||
# vgs
|
||||
|
||||
This will create the volume group using 32MB PE size in the name of **tecmint_add_vg** using 3 Physical volumes we created in last steps.
|
||||
|
||||
# vgcreate -s 32M tecmint_add_vg /dev/sda1 /dev/sdb1 /dev/sdc1
|
||||
|
||||
Next, verify the volume group by running vgs command again.
|
||||
|
||||
# vgs
|
||||
|
||||
![Create Volume Groups](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-10.jpg)
|
||||
Create Volume Groups
|
||||
|
||||
![Verify Volume Groups](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-11.jpg)
|
||||
Verify Volume Groups
|
||||
|
||||
Understanding vgs command output:
|
||||
|
||||
- Volume Group name.
|
||||
- Physical Volumes used in this Volume Group.
|
||||
- Shows free space available in this volume group.
|
||||
- Total Size of the Volume Group.
|
||||
- Logical Volumes inside this volume group, Here we have not yet created so there is 0.
|
||||
- SN = Number of Snapshots the volume group contains. (Later we can create a snapshot).
|
||||
- Status of the Volume group as Writeable, readable, resizeable, exported, partial and clustered, Here it is wz–nthat means w = Writable, z = resizeable..
|
||||
- Number of Physical Volume (PV) used in this Volume Group.
|
||||
|
||||
**7. **To Display more information about volume group use command.
|
||||
|
||||
# vgs -v
|
||||
|
||||
![Check Volume Group Information](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-12.jpg)
|
||||
Check Volume Group Information
|
||||
|
||||
**8. **To get more information about newly created volume groups, run the following command.
|
||||
|
||||
# vgdisplay tecmint_add_vg
|
||||
|
||||
![List New Volume Groups](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-13.jpg)
|
||||
List New Volume Groups
|
||||
|
||||
- Volume group name
|
||||
- LVM Architecture used.
|
||||
- It can be read and write state, ready to use.
|
||||
- This volume group can be resizeable.
|
||||
- No of Physical disk used and they are active.
|
||||
- Volume Group total size.
|
||||
- A Single PE size was 32 here.
|
||||
- Total number of PE available in this volume group.
|
||||
- Currently we have not created any LV inside this VG so its totally free.
|
||||
- UUID of this volume group.
|
||||
|
||||
### Creating Logical Volumes ###
|
||||
|
||||
**9. **Now, ceate 3 Logical Volumes in the name of **tecmint_documents**, **tecmint_manager** and **tecmint_public**. Here, we can see how to Create Logical Volumes Using PE size and Using GB Size. First, list the Current Logical Volumes using following command.
|
||||
|
||||
# lvs
|
||||
|
||||
![List Current Volume Groups](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-14.jpg)
|
||||
List Current Volume Groups
|
||||
|
||||
**10. **These Logical Volumes are in **vg_tecmint** Volume Group. List and see how much free spaces are there to create logical volumes using **pvs** command.
|
||||
|
||||
# pvs
|
||||
|
||||
![Check Free Space](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-15.jpg)
|
||||
Check Free Space
|
||||
|
||||
**11. **Volume group size is **54GB** and its unused, So we can Create LV in it. Let us divide volume group to equal size to create 3 Logical Volumes. That means **54GB**/3 = **18GB**, A single Logical Volume will be 18GB in Size after Creation.
|
||||
|
||||
#### Method 1: Creating Logical Volumes using PE Size’s ####
|
||||
|
||||
First let us create Logical Volumes Using Physical Extends (PE) size. We need to know Default PE size assigned for this Volume Group and Total PE available to create new Logical Volumes, Run the command to get the info using.
|
||||
|
||||
# vgdisplay tecmint_add_vg
|
||||
|
||||
![Create New Logical Volume](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-16.jpg)
|
||||
Create New Logical Volume
|
||||
|
||||
- Default PE Assigned for this VG is 32MB, Here Single PE size will be 32MB.
|
||||
- Total Available PE is 1725.
|
||||
|
||||
Just do and see a little Calculation using bc command.
|
||||
|
||||
# bc
|
||||
|
||||
----------
|
||||
|
||||
1725PE/3 = 575 PE.
|
||||
575 PE x 32MB = 18400 --> 18GB
|
||||
|
||||
![Calculate Disk Space](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-17.jpg)
|
||||
Calculate Disk Space
|
||||
|
||||
Press **CRTL+D** to Exit from **bc**. Let us now Create 3 Logical Volumes using 575 PE’s.
|
||||
|
||||
# lvcreate -l (Extend size) -n (name_of_logical_volume) (volume_group)
|
||||
|
||||
# lvcreate -l 575 -n tecmint_documents tecmint_add_vg
|
||||
|
||||
# lvcreate -l 575 -n tecmint_manager tecmint_add_vg
|
||||
|
||||
# lvcreate -l 575 -n tecmint_public tecmint_add_vg
|
||||
|
||||
- -**l** – Creating using Extent Size
|
||||
- -**n** – Give a Logical Volume name.
|
||||
|
||||
List the Created Logical Volumes using lvs command.
|
||||
|
||||
# lvs
|
||||
|
||||
![List Created Logical Volumes](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-18.jpg)
|
||||
List Created Logical Volumes
|
||||
|
||||
#### Method 2: Creating Logical Volumes using GB Size’s ####
|
||||
|
||||
While Creating Logical Volume using GB size we cannot get the exact size. So, the better way is to create using extend.
|
||||
|
||||
# lvcreate -L 18G -n tecmint_documents tecmint_add_vg
|
||||
|
||||
# lvcreate -L 18G -n tecmint_manager tecmint_add_vg
|
||||
|
||||
# lvcreate -L 18G -n tecmint_public tecmint_add_vg
|
||||
|
||||
# lvcreate -L 17.8G -n tecmint_public tecmint_add_vg
|
||||
|
||||
List the Created logical Volumes using lvs command.
|
||||
|
||||
# lvs
|
||||
|
||||
![Verify Created Logical Volumes](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-19.jpg)
|
||||
Verify Created Logical Volumes
|
||||
|
||||
Here, we can see while creating 3rd LV we can’t Round-up to 18GB, It is because of small changes in size, But this issue will be ignored while creating LV using Extend size.
|
||||
|
||||
### Creating File System ###
|
||||
|
||||
**12. **For using the logical volumes we need to format. Here I am using ext4 file-system to create the volumes and going to mount under **/mnt/**.
|
||||
|
||||
# mkfs.ext4 /dev/tecmint_add_vg/tecmint_documents
|
||||
|
||||
# mkfs.ext4 /dev/tecmint_add_vg/tecmint_public
|
||||
|
||||
# mkfs.ext4 /dev/tecmint_add_vg/tecmint_manager
|
||||
|
||||
![Create Ext4 File System](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-20.jpg)
|
||||
Create Ext4 File System
|
||||
|
||||
**13. **Let us Create Directories in **/mnt** and Mount the Logical volumes what we have created file-system.
|
||||
|
||||
# mount /dev/tecmint_add_vg/tecmint_documents /mnt/tecmint_documents/
|
||||
|
||||
# mount /dev/tecmint_add_vg/tecmint_public /mnt/tecmint_public/
|
||||
|
||||
# mount /dev/tecmint_add_vg/tecmint_manager /mnt/tecmint_manager/
|
||||
|
||||
List and confirm the Mount point using.
|
||||
|
||||
# df -h
|
||||
|
||||
![Mount Logical Volumes](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-22.jpg)
|
||||
Mount Logical Volumes
|
||||
|
||||
#### Permanent Mounting ####
|
||||
|
||||
It’s now temporarily mounted, for permanent mount we need to add the entry in fstab, for that let us get the mount entry from mtab using
|
||||
|
||||
# cat /etc/mtab
|
||||
|
||||
We need to make slight changes in fstab entry while entering the mount entry contents copies from mtab, we need to change the rw to defaults
|
||||
|
||||
# vim /etc/fstab
|
||||
|
||||
Our fstab Entry want to be similar to below sample. Save and exit from fstab using wq!.
|
||||
|
||||
/dev/mapper/tecmint_add_vg-tecmint_documents /mnt/tecmint_documents ext4 defaults 0 0
|
||||
/dev/mapper/tecmint_add_vg-tecmint_public /mnt/tecmint_public ext4 defaults 0 0
|
||||
/dev/mapper/tecmint_add_vg-tecmint_manager /mnt/tecmint_manager ext4 defaults 0 0
|
||||
|
||||
![Get mtab Mount Entry](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-23.jpg)
|
||||
Get mtab Mount Entry
|
||||
|
||||
![Open fstab File](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-24.jpg)
|
||||
Open fstab File
|
||||
|
||||
![Add Auto Mount Entry](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-25.jpg)
|
||||
Add Auto Mount Entry
|
||||
|
||||
Execute the command mount -a to check for the fstab entry before restart.
|
||||
|
||||
# mount -av
|
||||
|
||||
![Verify fstab Entry](http://www.tecmint.com/wp-content/uploads/2014/07/Create-Logical-Volume-Storage-26.jpg)
|
||||
Verify fstab Entry
|
||||
|
||||
Here we have seen how to setup flexible storage with logical volumes by using physical disk to physical volume, physical volume to volume group, volume group to logical volumes.
|
||||
|
||||
In my upcoming future articles, I will see how to extend the volume group, logical volumes, reducing logical volume, taking snapshot and restore from snapshot. Till then stay updated to TecMint for more such awesome articles.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: http://www.tecmint.com/create-lvm-storage-in-linux/
|
||||
|
||||
作者:[Babin Lonston][a]
|
||||
译者:[译者ID](https://github.com/译者ID)
|
||||
校对:[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创翻译,[Linux中国](http://linux.cn/) 荣誉推出
|
||||
|
||||
[a]:http://www.tecmint.com/author/babinlonston/
|
Loading…
Reference in New Issue
Block a user