Disk drives and partitions
IDE disks are known as /dev/hda, /dev/hdb, /dev/hdc, /dev/hdd, and so on.
Any disks using the SCSI emulation layer are known as /dev/sda, /dev/sdb, /dev/sdc, and so on. These include SCSI disks, SATA disks, and, in newer kernels, IDE disks.
Three types of partitions:
Filesystem container. At least one must exist, and up to four can exist on a single physical disk. They are identified with numbers 1 to 4, such as /dev/hda1, /dev/hda2, and so on.
A variant of a primary partition, but it cannot contain a filesystem. Instead, it contains one or more logical partitions. Only one extended partition may exist, and it takes one of the four possible spots for primary partitions.
Created within the extended partition. From 1 to 12 logical partitions may be created. They are numbered from 5 to 16, such as /dev/hda5, /dev/hda6, and so on.
Up to 15 partitions with filesystems may exist on a single physical disk.