Creating a Logical Volume Using LVM
Scenarios
This section shows how to create a 15 GB logical volume based on two 10 GB EVS disks.
Logical volumes can be created based on EVS disks with different specifications.
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Prerequisites
Two EVS disks have been attached to the ECS where LVM is installed.
Procedure
- Log in to the ECS as user root.
- Run the following command to view and take note of the device names:
fdisk -l | grep /dev/vd | grep -v vda
Information similar to the following is displayed:
[root@ecs-lvmtest ~]# fdisk -l | grep /dev/vd | grep -v vda Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 sectors Disk /dev/vdc: 10.7 GB, 10737418240 bytes, 20971520 sectors
In the command output, two EVS disks are attached to the ECS, and the device names are /dev/vdb and /dev/vdc.
- Create physical volumes using EVS disks.
- Run the following command to create physical volumes using EVS disks:
pvcreate Device name 1 Device name 2 Device name 3...
Parameter description:
Device name: indicates the disk device name. If multiple physical volumes need to be created in a batch, specify multiple device names and separate them with spaces.
In this example, run the following command:
pvcreate /dev/vdb /dev/vdc
Information similar to the following is displayed:
[root@ecs-lvmtest ~]# pvcreate /dev/vdb /dev/vdc Physical volume "/dev/vdb" successfully created. Physical volume "/dev/vdc" successfully created.
- Run the following command to query details of the physical volumes:
Information similar to the following is displayed:
[root@ecs-lvmtest ~]# pvdisplay "/dev/vdc" is a new physical volume of "10.00 GiB" --- NEW Physical volume --- PV Name /dev/vdc VG Name PV Size 10.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID dypyLh-xjIj-PvG3-jD0j-yup5-O7SI-462R7C "/dev/vdb" is a new physical volume of "10.00 GiB" --- NEW Physical volume --- PV Name /dev/vdb VG Name PV Size 10.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID srv5H1-tgLu-GRTl-Vns8-GfNK-jtHk-Ag4HHB
In the command output, the system has two new physical volumes named /dev/vdc and /dev/vdb.
- Run the following command to create physical volumes using EVS disks:
- Create a volume group for the physical volumes.
- Run the following command to create a volume group:
vgcreate Volume group name Physical volume name 1 Physical volume name 2 Physical volume name 3...
Parameter description:
- Volume group name: Specify a volume group name, for example, vgdata.
- Physical volume name: Specify the name of a physical volume to be added to the volume group. Multiple names are separated with spaces.
In this example, run the following command:
vgcreate vgdata /dev/vdb /dev/vdc
Information similar to the following is displayed:
[root@ecs-lvmtest ~]# vgcreate vgdata /dev/vdb /dev/vdc Volume group "vgdata" successfully created
- Run the following command to query details of the volume group:
Information similar to the following is displayed:
[root@ecs-lvmtest ~]# vgdisplay --- Volume group --- VG Name vgdata System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 1 VG Access read/write VG Status resizable MAX LV 0 Cur LV 0 Open LV 0 Max PV 0 Cur PV 2 Act PV 2 VG Size 19.99 GiB PE Size 4.00 MiB Total PE 5118 Alloc PE / Size 0 / 0 Free PE / Size 5118 / 19.99 GiB VG UUID NLkZV7-hYYE-0w66-tnlt-Y6jL-Ik7S-76w4P6
- Run the following command to create a volume group:
- Create a logical volume in the volume group.
- Run the following command to create a logical volume:
lvcreate -L Logical volume size -n Logical volume name Volume group name
Parameter description:
- Logical volume size: Specify a value smaller than the volume group's available space, either in MB or GB.
- Logical volume name: Specify a volume name, for example, lvdata1.
- Volume group name: Specify the name of the volume group where the logical volume belongs.
In this example, run the following command:
lvcreate -L 15GB -n lvdata1 vgdata
Information similar to the following is displayed:
[root@ecs-lvmtest ~]# lvcreate -L 15GB -n lvdata1 vgdata Logical volume "lvdata1" created.
- Run the following command to query details of the logical volume:
Information similar to the following is displayed:
[root@ecs-lvmtest ~]# lvdisplay --- Logical volume --- LV Path /dev/vgdata/lvdata1 LV Name lvdata1 VG Name vgdata LV UUID c7mNcF-CdPW-5PLD-1gVj-QZpB-nHfy-PHXchV LV Write Access read/write LV Creation host, time ecs-lvmtest.novalocal, 2018-11-29 11:28:18 +0800 LV Status available # open 0 LV Size 15.00 GiB Current LE 3840 Segments 2 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 252:0
- Run the following command to create a logical volume:
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