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Wecome To Linux
How LVM Works:
LVM has basically three terms, Physical Volume PV, Volume Group VG, Logical Volume LV.
- PV – It’s a raw hard drive that it initialized to work with LVM, such as /dev/sdb, /dev/sdc, /dev/sdb1 etc.
- VG – Many PV is combined into one VG. You can create many VGs and each of them has a unique name.
- LV – You can create many LVs from a VG. You can extend, reduce the LV size on the fly. The LV also has unique names. You format the LV into ext4, zfs, btrfs etc filesystems, mount it and use it as you do other ordinary partitions.
Installing LVM:
LVM may not be installed on your CentOS 7 machine. But it is available in the official package repository of CentOS 7.
First update the YUM package repository cache with the following command:
[root@clouddevops opt]#yum makecache
Run the following command to install LVM on CentOS 7:
[root@clouddevops opt]#yum install lvm2
Now press y and then press <Enter> to continue.
LVM should be installed.
Initializing Disk for LVM:
[root@clouddevops opt]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x0003d1b7 Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 83886079 40893440 8e Linux LVM Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/centos-root: 37.7 GB, 37706792960 bytes, 73646080 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/centos-swap: 4160 MB, 4160749568 bytes, 8126464 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes[root@clouddevops ~]#
[root@clouddevops opt]# df -h
Filesystem Size Used Avail Use% Mounted on devtmpfs 894M 0 894M 0% /dev tmpfs 910M 0 910M 0% /dev/shm tmpfs 910M 11M 900M 2% /run tmpfs 910M 0 910M 0% /sys/fs/cgroup /dev/mapper/centos-root 36G 7.9G 28G 23% / /dev/sda1 1014M 346M 669M 35% /boot tmpfs 182M 28K 182M 1% /run/user/0 /dev/sr0 4.5G 4.5G 0 100% /run/media/root/CentOS 7 x86_64
[root@clouddevops ~]#
You can use the raw disk such as /dev/sdb or /dev/sdc as LVM PV. LVM has no problem with that but it is not recommended as other operating systems won’t be able to detect LVM metadata and you may not be able to tell whether the disk is set up to use LVM if you have many disks lying around.
So I recommend you create a single partition on your hard drive with all the available space and change the partition type to Linux LVM or 8E.
Use fdisk to create a single partition on the disk, let’s say /dev/sdb:
[root@clouddevops opt]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition g create a new empty GPT partition table G create an IRIX (SGI) partition table l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only)
Now type in n and press <Enter> to create a new partition. Now keep pressing <Enter> to accept the defaults.
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-209715199, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-209715199, default 209715199): +25G
Partition 1 of type Linux and of size 25 GiB is set
Command (m for help): p
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x30a7e19f
Device Boot Start End Blocks Id System
/dev/sdb1 2048 52430847 26214400 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@clouddevops ~]#
[root@clouddevops opt]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x0003d1b7 Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 83886079 40893440 8e Linux LVM Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x30a7e19f Device Boot Start End Blocks Id System /dev/sdb1 2048 52430847 26214400 83 Linux Disk /dev/mapper/centos-root: 37.7 GB, 37706792960 bytes, 73646080 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/centos-swap: 4160 MB, 4160749568 bytes, 8126464 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes
[root@clouddevops ~]#
The partition should be created.
[root@clouddevops opt]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help):m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition g create a new empty GPT partition table G create an IRIX (SGI) partition table l list known partition types m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partition's system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only)
Now type in t and press <Enter>.
Command (m for help): t Selected partition 1 Hex code (type L to list all codes):l 0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris 1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT- 2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT- 3 XENIX usr 3c PartitionMagic 84 OS/2 hidden C: c6 DRDOS/sec (FAT- 4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx 5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data 6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / . 7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility 8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt 9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi eb BeOS fs e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/ 10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b 11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor 12 Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor 14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f2 DOS secondary 16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS 17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE 18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto 1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep 1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT 1e Hidden W95 FAT1 80 Old Minix Hex code (type L to list all codes):8e
Now type in 8e as the Hex code and press <Enter>. The partition type should be set to Linux LVM.
Now type in t and press <Enter>. Then type in 8e as the Hex code and press <Enter>. The partition type should be set to Linux LVM.
Hex code (type L to list all codes): 8e Changed type of partition 'Linux' to 'Linux LVM' Command (m for help): p Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x30a7e19f Device Boot Start End Blocks Id System /dev/sdb1 2048 52430847 26214400 8e Linux LVM
Now type in w and press <Enter> to save the changes.
Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
The partition /dev/sdb1 is now ready to be used with LVM.
Create one more Partition sdb2 with sdb raw disk fallow the steps same as like above or fallowing bellow steps.
[root@clouddevops opt]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x0003d1b7 Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 83886079 40893440 8e Linux LVM Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x30a7e19f Device Boot Start End Blocks Id System /dev/sdb1 2048 52430847 26214400 8e Linux LVM Disk /dev/mapper/centos-root: 37.7 GB, 37706792960 bytes, 73646080 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/centos-swap: 4160 MB, 4160749568 bytes, 8126464 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes
[root@clouddevops ~]#
Create a 2nd one sdb2 partition like fallowing bellow steps
[root@clouddevops opt]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p): p
Partition number (2-4, default 2):
First sector (52430848-209715199, default 52430848):
Using default value 52430848
Last sector, +sectors or +size{K,M,G} (52430848-209715199, default 209715199): +25G
Partition 2 of type Linux and of size 25 GiB is set
Command (m for help): p
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x30a7e19f
Device Boot Start End Blocks Id System
/dev/sdb1 2048 52430847 26214400 8e Linux LVM
/dev/sdb2 52430848 104859647 26214400 83 Linux
Command (m for help):
Change the id from 83 to 8e
See the Bellow steps to convert from 83 to 8e
[root@clouddevops opt]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help): t Partition number (1,2, default 2): 2 Hex code (type L to list all codes): 8e Changed type of partition 'Linux' to 'Linux LVM' Command (m for help): p Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x30a7e19f Device Boot Start End Blocks Id System /dev/sdb1 2048 52430847 26214400 8e Linux LVM /dev/sdb2 52430848 104859647 26214400 8e Linux LVM Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
[root@clouddevops ~]#
List the All Physical Volumes (PV)
[root@clouddevops opt]# pvs
PV VG Fmt Attr PSize PFree /dev/sda2 centos lvm2 a-- <39.00g 4.00m
OR
[root@clouddevops opt]# pvdisplay
--- Physical volume --- PV Name /dev/sda2 VG Name centos PV Size <39.00 GiB / not usable 3.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 9983 Free PE 1 Allocated PE 9982 PV UUID S1ncTT-Mlnf-XSfH-J0yi-E6dd-CKri-0GAy4U
[root@clouddevops ~]#
Adding the Disk to LVM PV:
Now run the following command to add the disk /dev/sdb1 to the LVM as PV:
[root@clouddevops opt]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
[root@clouddevops ~]#
You can list all the PV with the following command:
[root@clouddevops opt]# pvs
PV VG Fmt Attr PSize PFree /dev/sda2 centos lvm2 a-- <39.00g 4.00m /dev/sdb1 lvm2 --- 25.00g 25.00g
OR
[root@clouddevops opt]# pvdisplay
--- Physical volume --- PV Name /dev/sda2 VG Name centos PV Size <39.00 GiB / not usable 3.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 9983 Free PE 1 Allocated PE 9982 PV UUID S1ncTT-Mlnf-XSfH-J0yi-E6dd-CKri-0GAy4U "/dev/sdb1" is a new physical volume of "25.00 GiB" --- NEW Physical volume --- PV Name /dev/sdb1 VG Name PV Size 25.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID rgVeKF-foP0-ri65-rxob-LlZG-B3bq-0Rfcsj
[root@clouddevops ~]#
OR
If you want to display more information about any specific PV, let’s say /dev/sdb1, then run the following command:
[root@clouddevops opt]# pvdisplay /dev/sdb1
"/dev/sdb1" is a new physical volume of "25.00 GiB" --- NEW Physical volume --- PV Name /dev/sdb1 VG Name PV Size 25.00 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID rgVeKF-foP0-ri65-rxob-LlZG-B3bq-0Rfcsj
[root@clouddevops ~]#
[root@clouddevops opt]# pvscan
PV /dev/sda2 VG centos lvm2 [<39.00 GiB / 4.00 MiB free] PV /dev/sdb1 lvm2 [25.00 GiB] Total: 2 [<64.00 GiB] / in use: 1 [<39.00 GiB] / in no VG: 1 [25.00 GiB]
[root@clouddevops ~]#
Creating Volume Groups:
Now you can create a VG out of as many PV as you have available. Right now I have only one PV /dev/sdb1 available.
[root@clouddevops opt]# vgs
VG #PV #LV #SN Attr VSize VFree centos 1 2 0 wz--n- <39.00g 4.00m
Compelte Information about VOLUME GROUP (VG)
[root@clouddevops ~]# vgdisplay
--- Volume group --- VG Name centos System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size <39.00 GiB PE Size 4.00 MiB Total PE 9983 Alloc PE / Size 9982 / 38.99 GiB Free PE / Size 1 / 4.00 MiB VG UUID S7d6eF-L8Xv-XDyc-eKDb-Qvo0-JHr2-JGhk1l
[root@clouddevops ~]#
Run the following command to create VG clouddevops with PV /dev/sdb1:
[root@clouddevops opt]# vgcreate clouddevops /dev/sdb1
Volume group "clouddevops" successfully created
[root@clouddevops ~]#
Now you can list all the VGs with the following command:
[root@clouddevops opt]# vgscan
Reading volume groups from cache. Found volume group "centos" using metadata type lvm2 Found volume group "clouddevops" using metadata type lvm2
[root@clouddevops ~]#
You can display more information about any specific VG, such as clouddevops with the following command:
[root@clouddevops opt]# vgdisplay clouddevops
--- Volume group --- VG Name clouddevops System ID Format lvm2 Metadata Areas 1 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 1 Act PV 1 VG Size <25.00 GiB PE Size 4.00 MiB Total PE 6399 Alloc PE / Size 0 / 0 Free PE / Size 6399 / <25.00 GiB VG UUID Cffkp2-iStu-fcsp-gWYf-FTfi-cN60-jmWOjA
[root@clouddevops ~]#
Extending Volume Groups:
If you wish you can add more PV to an existing VG clouddevops with the following command:
[root@clouddevops opt]# vgextend clouddevops /dev/sdb2
Physical volume "/dev/sdb2" successfully created. Volume group "clouddevops" successfully extended
[root@clouddevops ~]#
Creating Logical Volumes:
Now you can create as many LVs as you want using a VG, in my case VG clouddevops.
we can create from 1MB aslo but here i am using25GB LV clouddevops from VG clouddevops with the following command:
[root@clouddevops opt]# lvcreate --size 20G --name devopslvm clouddevops
Logical volume "devopslvm" created.[root@clouddevops ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root centos -wi-ao---- <35.12g swap centos -wi-ao---- <3.88g devopslvm clouddevops -wi-a----- 20.00g[root@clouddevops ~]#
Let’s create another LV lvmtwo of size 10GB from VG clouddevops with the following command:
[root@clouddevops opt]# lvcreate --size 10G --name lvm_two clouddevops
Logical volume "lvm_two" created.
[root@clouddevops opt]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root centos -wi-ao---- <35.12g swap centos -wi-ao---- <3.88g devopslvm clouddevops -wi-a----- 20.00g lvm_two clouddevops -wi-a----- 10.00g
[root@clouddevops ~]#
Now you can list all the LVs with the following commands:
[root@clouddevops opt]# lvscan
ACTIVE '/dev/centos/swap' [<3.88 GiB] inherit ACTIVE '/dev/centos/root' [<35.12 GiB] inherit ACTIVE '/dev/clouddevops/devopslvm' [20.00 GiB] inherit ACTIVE '/dev/clouddevops/lvm_two' [10.00 GiB] inherit
[root@clouddevops ~]#
Or
[root@clouddevops opt]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root centos -wi-ao---- <35.12g swap centos -wi-ao---- <3.88g devopslvm clouddevops -wi-a----- 20.00g lvm_two clouddevops -wi-a----- 10.00g
[root@clouddevops ~]#
You can also display more information about any specific LV with the following command:
$ sudo lvdisplay VG_NAME/LV_NAMEIn my case, VG_NAME is clouddevops and LV_NAME is clouddevops
[root@clouddevops opt]# lvdisplay /dev/clouddevops/clouddevops
--- Logical volume --- LV Path /dev/clouddevops/clouddevops LV Name clouddevops VG Name clouddevops LV UUID fgru9C-ICZi-BfmR-mvJg-0Fjb-FxUW-2D0MYy LV Write Access read/write LV Creation host, time clouddevops.com, 2020-08-15 23:00:56 +0530 LV Status available # open 0 LV Size 10.00 GiB Current LE 2560 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:4
[root@clouddevops ~]#
Formatting and Mounting Logical Volumes:
You can access your LVs just as you do with ordinary hard drive partitions such as /dev/sdb1, /dev/sdc2 etc.
The LVs are available as /dev/VG_NAME/LV_NAME
For example, if my VG_NAME is clouddevops, and LV_NAME is clouddevops, then the LV is available as /dev/clouddevops/clouddevops
You can use /dev/clouddevops/clouddevops just as you use an ordinary hard drive partition /dev/sdb1.
Once you’ve created a LV, you need to format it.
Run the following command to format /dev/clouddevops/clouddevops LV to EXT4 filesystem:
[root@clouddevops opt]# mkfs.ext4 /dev/clouddevops/clouddevops
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
655360 inodes, 2621440 blocks
131072 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2151677952
80 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
[root@clouddevops ~]#
Now run the following command to create a mount point where you want to mount /dev/clouddevops/clouddevops LV:
[root@clouddevops opt]# mkdir /opt/clouddevops
[root@clouddevops opt]# ll /opt/
total 0 drwxr-xr-x. 2 root root 6 Aug 15 23:16 clouddevops drwx--x--x. 4 root root 28 Aug 9 08:45 containerd drwxr-xr-x. 2 root root 6 Oct 31 2018 rh
[root@clouddevops ~]#
Now you can mount /dev/clouddevops/clouddevops to any empty directory such as /var/www/wordpress with the following command:
[root@clouddevops opt]# mount /dev/clouddevops/clouddevops /opt/clouddevops/
[root@clouddevops ~]#
As you can see, the LV is mounted to the desired mount point:
[root@clouddevops opt]# df -h
Filesystem Size Used Avail Use% Mounted on devtmpfs 1.9G 0 1.9G 0% /dev tmpfs 1.9G 0 1.9G 0% /dev/shm tmpfs 1.9G 13M 1.9G 1% /run tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup /dev/mapper/centos-root 36G 7.9G 28G 23% / /dev/sda1 1014M 346M 669M 35% /boot tmpfs 378M 24K 378M 1% /run/user/0 /dev/sr0 4.5G 4.5G 0 100% /run/media/root/CentOS 7 x86_64 /dev/mapper/clouddevops-clouddevops 9.8G 37M 9.2G 1% /opt/clouddevops
[root@clouddevops ~]#
Now you can use copy and paste files, create new files and directories in the /var/www/wordpress directory.
Extending Logical Volumes:
LVM is a good tool for quota management. You give away the space you need, no more, no less on each LVs. But if you do require more space, you can always resize the LV on the fly.
Even if you’re not doing quota management, when you’re out of disk space, you can just add new hard drives, add it to the PV, extend the VG with your new PV, extend the LV and you’re good to go.
For example, to add 5GB more to our LV clouddevops created from VG clouddevops, run the following command:
Note: You can use G keyword for GB. For example, --size +5G
[root@clouddevops opt]# lvextend --size +5G --resizefs clouddevops/clouddevops
Size of logical volume clouddevops/clouddevops changed from 10.00 GiB (2560 extents) to 15.00 GiB (3840 extents). Logical volume clouddevops/clouddevops successfully resized. resize2fs 1.42.9 (28-Dec-2013) Filesystem at /dev/mapper/clouddevops-clouddevops is mounted on /opt/clouddevops; on-line resizing required old_desc_blocks = 2, new_desc_blocks = 2 The filesystem on /dev/mapper/clouddevops-clouddevops is now 3932160 blocks long.
[root@clouddevops ~]#
The clouddevops LV should be resized as you can see from the screenshot below.
[root@clouddevops opt]# df -h
Filesystem Size Used Avail Use% Mounted on devtmpfs 1.9G 0 1.9G 0% /dev tmpfs 1.9G 0 1.9G 0% /dev/shm tmpfs 1.9G 13M 1.9G 1% /run tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup /dev/mapper/centos-root 36G 7.9G 28G 23% / /dev/sda1 1014M 346M 669M 35% /boot tmpfs 378M 24K 378M 1% /run/user/0 /dev/sr0 4.5G 4.5G 0 100% /run/media/root/CentOS 7 x86_64 /dev/mapper/clouddevops-clouddevops 15G 41M 14G 1% /opt/clouddevops
[root@clouddevops ~]#
That’s how you install and configure LVM on CentOS 7. Thanks for reading this article.
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