Unix (linux) has one root, one unified hierarchy. Home will be mounted on /home.
Sub-trees can be grafted on, but there is one tree per computer. You can even share sub-trees between computers using network file shares, but they are sub-trees not new trees.
mount -l on a command line to see all mounts. Note this includes a few special mounts that have no backing store. Also
df -h to get usage info.
Example from my system:
#how full are my filesystems.
df -h --print-type
Filesystem Type Size Used Avail Use% Mounted on
/dev/sda5 ext4 20G 9.7G 8.7G 53% /
tmpfs tmpfs 1.5G 0 1.5G 0% /lib/init/rw
udev tmpfs 1.5G 284K 1.5G 1% /dev
tmpfs tmpfs 1.5G 4.0K 1.5G 1% /dev/shm
/dev/sda6 ext4 87G 64G 18G 79% /home
/dev/sdb2 ext4 230G 85G 133G 39% /media/extra
#detailed info on what is mounted, but no size or usage info.
/dev/sda5 on / type ext4 (rw,dirsync,errors=remount-ro,barrier=1,data=journal,auto_da_alloc,journal_checksum) [debian]
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
/dev/sda6 on /home type ext4 (rw,dirsync,errors=remount-ro,barrier=1,data=journal,auto_da_alloc,journal_checksum) [debian-home]
fusectl on /sys/fs/fuse/connections type fusectl (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
/dev/sdb2 on /media/extra type ext4 (rw,nosuid,nodev,uhelper=udisks) [extra]
- The root file-system
/ [or c:] is on primary hard-disk extended partition 1 (5)
/lib/init/rw we have a temporary ram based file system. (probably used by init, process 1, probably best it ignore it)
/proc we have the proc file-system. This is magic, it is a dynamic file-system, it can tell you lots of cool stuff about you processes/system.
/sys we have the sys file-system. (see what I said about
/dev we have udev. udev manages
/dev. /dev is a where lots of magic lives, lots of things that you may not think of as files live there: partitions, audio/video input output, keyboard, mouse, a black-hole (
/dev/null), a source of nothing (
/home is primary disk partition extended 2 (6). This is where users directories are. [Equivalent to
?\User on modern Microsoft os, where ? may be C, or something else].
/media/extra is an external hard-disk.
/media is a place that external drives get mounted on automatically. In
/media is also a directories
/media/cdrom0 the first a reference to the other. They are empty directories, but if I put in a cdrom. Then the cd appears here. [ Equivalent to
#what swap have I got, and what is being used.
Filename Type Size Used Priority
/dev/sda7 partition 4095992 0 -1
#what disks and partitions have I got.
ls -l /dev/disk/by-path/*
lrwxrwxrwx 1 root root 9 Jul 15 22:39 /dev/disk/by-path/pci-0000:00:1d.7-usb-0:1.1:1.0-scsi-0:0:0:0 -> ../../sdb
lrwxrwxrwx 1 root root 10 Jul 15 19:36 /dev/disk/by-path/pci-0000:00:1d.7-usb-0:1.1:1.0-scsi-0:0:0:0-part2 -> ../../sdb2
lrwxrwxrwx 1 root root 9 Jul 15 22:39 /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 -> ../../sda
lrwxrwxrwx 1 root root 10 Jul 15 22:39 /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0-part3 -> ../../sda3
lrwxrwxrwx 1 root root 10 Jul 15 19:36 /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0-part5 -> ../../sda5
lrwxrwxrwx 1 root root 10 Jul 15 19:36 /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0-part6 -> ../../sda6
lrwxrwxrwx 1 root root 10 Jul 15 19:36 /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0-part7 -> ../../sda7
lrwxrwxrwx 1 root root 9 Jul 15 19:36 /dev/disk/by-path/pci-0000:00:1f.2-scsi-1:0:0:0 -> ../../sr0
/dev is the directory that raw devices live in.
/dev/sd* are disk partitions.
/dev/sda is primary hard disk
/dev/sdb is secondary hard disk in my case an external one.
/dev/sd?1 is first partition of a disk. 1,2,3,4 are primary partitions, 5,6,7,etc are secondary partitions.