102.1 Design hard disk layout

102.1 Design hard disk layout

1. disks, partitions, filesystems and volumes.

   • Every disk needs at least one partition
   • Inside each partition there is a filesystem
   • Partitions cannot span multiple disks
   • (LVM) multiple partitions can be combined, even across disks, to form a single logical volume.
   • allocating filesystems and swap space to separate partitions or disks when needed.

2. Mount Points

   • removable devices are automatically mounted under /media/USER/LABEL
   • /boot
     • The boot partition contains files used by the bootloader to load the operating system.
     • The boot partition is usually the first partition on the disk
       • located at the start of the disk and ends before cylinder 1024 (528 MB),
     • A good size is around 300 MB.
   • /home
   • swap
   • /var
     • /var/cache /var/tmp /var/log /var/www/html /var/lib/mysql

3. The EFI System Partition (ESP)

   • machines based on the Unified Extensible Firmware Interface (UEFI) to store boot loaders and kernel images for the operating systems installed.
   • Linux system is mounted under /boot/efi.

4. LVM

   • The basic unit is the Physical Volume (PV),
   • PVs are grouped into Volume Groups (VG)
   • Each volume in a Volume Group is subdivided into fixed-sized pieces called extents.
   • Extents on a PV are called Physical Extents (PE), while those on a Logical Volume are Logical Extents (LE
   • Volume Groups can be subdivided into Logical Volumes (LVs)
   • A device will be created in /dev, named as /dev/VGNAME/LVNAME, where VGNAME is the name of the Volume Group, and LVNAME is the name of the Logical Volume.