LVM stands for Logical Volume Manager.<\/p>\n
With LVM, we can create logical partitions that can span across one or more physical hard drives. First, the hard drives are divided into physical volumes, then those physical volumes are combined together to create the volume group and finally the logical volumes are created from volume group.<\/p>\n
The LVM commands listed in this article are used under Ubuntu Distribution. But, it is the same for other Linux distributions. To create a LVM, we need to run through the following steps.<\/p>\n In this step, we need to choose the physical volumes that will be used to create the LVM. We can create the physical volumes using pvcreate command as shown below.<\/p>\n As shown above two physical volumes are created \u2013 \/dev\/sda6 and \/dev\/sda7.<\/p>\n If the physical volumes are already created, you can view them using the pvscan command as shown below.<\/p>\n <\/p>\n You can view the list of physical volumes with attributes like size, physical extent size, total physical extent size, the free space, etc., using pvdisplay command as shown below.<\/p>\n Note : PE \u2013 Physical Extents are nothing but equal-sized chunks. The default size of extent is 4MB.<\/p>\n Volume groups are nothing but a pool of storage that consists of one or more physical volumes. Once you create the physical volume, you can create the volume group (VG) from these physical volumes (PV).<\/p>\n In this example, the volume group vol_grp1 is created from the two physical volumes as shown below.<\/p>\n LVM processes the storage in terms of extents. We can also change the extent size (from the default size 4MB) using -s flag.<\/p>\n <\/p>\n vgdisplay command lists the created volume groups.<\/p>\n Now, everything is ready to create the logical volumes from the volume groups. lvcreate command creates the logical volume with the size of 80MB.<\/p>\n To make a LV the MAX size use this<\/p>\n lvcreate -n logical_vol1 -l 100%FREE vol_grp1<\/p>\n Use lvdisplay command as shown below, to view the available logical volumes with its attributes.<\/p>\n After creating the appropriate filesystem on the logical volumes, it becomes ready to use for the storage purpose.<\/p>\n We can extend the size of the logical volumes after creating it by using lvextend utility as shown below. The changes the size of the logical volume from 80MB to 100MB.<\/p>\n We can also add additional size to a specific logical volume as shown below.<\/p>\n LVM stands for Logical Volume Manager. With LVM, we can create logical partitions that can span across one or more physical hard […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2489","post","type-post","status-publish","format-standard","hentry","category-info-on-tech"],"_links":{"self":[{"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/2489","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2489"}],"version-history":[{"count":0,"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=\/wp\/v2\/posts\/2489\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2489"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2489"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.designed79.co.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2489"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n<\/span>
\nBefore we start, install the lvm2 package as shown below.<\/p>\n$ sudo apt-get intall lvm2\r\n<\/pre>\n
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Select the Physical Storage Devices for LVM \u2013 Use pvcreate, pvscan, pvdisplay Commands<\/h3>\n
$ sudo pvcreate \/dev\/sda6 \/dev\/sda7 \r\nPhysical volume \"\/dev\/sda6\" successfully created \r\nPhysical volume \"\/dev\/sda7\" successfully created \r\n<\/pre>\n
$ sudo pvscan \r\n PV \/dev\/sda6 lvm2 [1.86 GB] \r\n PV \/dev\/sda7 lvm2 [1.86 GB] \r\n Total: 2 [3.72 GB] \/ in use: 0 [0 ] \/ in no VG: 2 [3.72 GB] \r\n<\/pre>\n
$ sudo pvdisplay \r\n--- Physical volume --- \r\n PV Name \/dev\/sda6 \r\n VG Name \r\n PV Size 1.86 GB \/ not usable 2.12 MB \r\n Allocatable yes \r\n PE Size (KByte) 4096 \r\n Total PE 476 \r\n Free PE 456 \r\n Allocated PE 20 \r\n PV UUID m67TXf-EY6w-6LuX-NNB6-kU4L-wnk8-NjjZfv \r\n \r\n --- Physical volume --- \r\n PV Name \/dev\/sda7 \r\n VG Name \r\n PV Size 1.86 GB \/ not usable 2.12 MB \r\n Allocatable yes \r\n PE Size (KByte) 4096 \r\n Total PE 476 \r\n Free PE 476 \r\n Allocated PE 0 \r\n PV UUID b031x0-6rej-BcBu-bE2C-eCXG-jObu-0Boo0x \r\n<\/pre>\n
Create the Volume Group \u2013 Use vgcreate, vgdisplay Commands<\/h3>\n
$ sudo vgcreate vol_grp1 \/dev\/sda6 \/dev\/sda7 \r\n Volume group \"vol_grp1\" successfully created \r\n<\/pre>\n
$ sudo vgdisplay \r\n --- Volume group --- \r\n VG Name vol_grp1 \r\n System ID \r\n Format lvm2 \r\n Metadata Areas 2 \r\n Metadata Sequence No 1 \r\n VG Access read\/write \r\n VG Status resizable \r\n MAX LV 0 \r\n Cur LV 0 \r\n Open LV 0 \r\n Max PV 0 \r\n Cur PV 2 \r\n Act PV 2 \r\n VG Size 3.72 GB \r\n PE Size 4.00 MB \r\n Total PE 952 \r\n Alloc PE \/ Size 0 \/ 0 \r\n Free PE \/ Size 952 \/ 3.72 GB \r\n VG UUID Kk1ufB-rT15-bSWe-5270-KDfZ-shUX-FUYBvR \r\n<\/pre>\n
LVM Create: Create Logical Volumes \u2013 Use lvcreate, lvdisplay command<\/h3>\n
$ sudo lvcreate -l 20 -n logical_vol1 vol_grp1 \r\n Logical volume \"logical_vol1\" created \r\n<\/pre>\n
\r\n$ sudo lvdisplay \r\n --- Logical volume --- \r\n LV Name \/dev\/vol_grp1\/logical_vol1 \r\n VG Name vol_grp1 \r\n LV UUID ap8sZ2-WqE1-6401-Kupm-DbnO-2P7g-x1HwtQ \r\n LV Write Access read\/write \r\n LV Status available \r\n # open 0 \r\n LV Size 80.00 MB \r\n Current LE 20 \r\n Segments 1 \r\n Allocation inherit \r\n Read ahead sectors auto \r\n - currently set to 256 \r\n Block device 252:0 \r\n<\/pre>\n
$ sudo mkfs.ext3 \/dev\/vol_grp1\/logical_vol1 \r\n<\/pre>\n
LVM resize: Change the size of the logical volumes \u2013 Use lvextend Command<\/h3>\n
$ sudo lvextend -L100 \/dev\/vol_grp1\/logical_vol1 \r\n Extending logical volume logical_vol1 to 100.00 MB \r\n Logical volume logical_vol1 successfully resized \r\n<\/pre>\n
$ sudo lvextend -L+100 \/dev\/vol_grp1\/logical_vol1 \r\n Extending logical volume logical_vol1 to 200.00 MB \r\n Logical volume logical_vol1 successfully resized \r\n<\/pre>\n