Simple and quickly understand Linux disk division

I have encountered such a scene a few days ago: One server is provided in the form of a virtual machine, only more than 30 g from the server disk space via DF -H, but finding that a 160G disk space is not mounted by fdisk -l, it is necessary to do not restart Mount 160g of disk. It has been handled several times before, but I don't forget it for some time. I will share this case and deepen my memory. Before you say this case, please briefly talk about the logical volume management (LVM) related knowledge you want to use. Logical volume management LVM is a versatile hard disk system tool. Whether in Linux or other similar systems, it is very easy. Traditional partitions use fixed size partitions, re-adjust the size is very troublesome. However, LVM can create and manage the "logical" volume instead of using physical hard drives directly. It is possible to expand the management logical volume of the administrator to expand, easy to operate, and not damaged the stored data. The new hard drive can be added to the LVM to expand the existing logical volume. LVM does not need to be restarted to let the kernel know the existence of the partition. LVM uses a hierarchical structure as shown below. At the top of the figure, the first is the actual physical disk and its divided partition and the physical volume (PV) thereon. One or more physical volumes can be used to create a volume group (VG). The logical volume (LV) can then be created based on the volume group. As long as there is available space in the volume group, you can create a logical volume as you want. The file system is created on the logical volume and can then mount and access at the operating system. Case: Disk expansion 1. View disk file free space, found that only 30 available disk space [root @ server tomcat-atm] # df -h 2. View the details of disk space pair, you can see a 160G disk [root @ Server Tomcat-ATM] # fdisk -l 3. Create a disk partition, use the '8e' type to make it available for LVM [root @ server tomcat-atm] # fdisk / dev / sdb 4. Create a physical volume Root @ Server Tomcat-ATM] # pvcreate / dev / sdb Physical Volume "/ dev / sdb" SuccessFully CREATED 5. Check the creation of the physical volume [root @ server tomcat-atm] # pvdisplay 6. Extended volume group [root @ server Tomcat-ATM] # VGEXTEND CENTOS / DEV / SDB Volume Group "Centos" SuccessFully Extended 7. View the volume group [root @ server tomcat-atm] # vgdisplay 8. Expand LVM volume [root @ server Tomcat-ATM] # LVEXTEND -L + 100% free / dev / mapper / centos-root Size of Logical Volume Centos / Root Changed from 35.47 GIB (9080 Extents) To 185.50 Gib (47489 Extents). Logical Volume Root SuccessFully Resize. 9. Extended capacity [root @ server Tomcat-ATM] # xfs_growfs / dev / mapper / centos-root 10. View disk space, you can see the successful expansion, read full text, original title: 3 minutes to understand Linux disk division Article Source: [Micro Signal: Magedu-Linux, WeChat Public Number: Master Linux Operations] Welcome to add attention! Please indicate the source of the article.