[[linux_wiki:file_system_hierarchy]]

File System Hierarchy

General Information

Some of the most common top level directories in the Linux file system.

Checklist

  • Distro(s): Any

Sources


Top Level Directories

EL7 = Enterprise Linux 7 (Red Hat, CentOS, Scientific)

Directory Used For
/ Root directory; file system tree starts here
/bin Executable programs needed to repair system; essential during boot;
EL7 symlinks /bin → /usr/bin
/boot All files needed to boot the Linux kernel
/dev Special/device files; refer to physical device
/etc “etcetera”; configuration files local to the system
/home User local home directories
/lib and /lib64 Shared libraries used by programs in /boot,/bin, /sbin;
EL7 symlinks /lib → /usr/lib and /lib64 → /usr/lib64
/media and /mnt Mount points for removable media and temporary file systems respectively
/opt Add on or optional packages
/proc Pseudo-filesystem that provides information on running processes and the kernel
/root Home directory for the root user
/run Process/user specific info created since last boot
/sbin Similar to /bin, except for system administration not used by regular users;
EL7 symlinks /sbin → /usr/sbin
/srv Directory to use for data used by services (such as NFS, FTP, HTTP)
/sys To interface with hardware devices managed by the kernel
/tmp Temporary files that could be deleted without warning during boot
/usr Directory containing sub directories with program files, libraries, and documentation. Typically mimics the contents of /. EL6: Not required during boot. EL7: Important directory contents has been relocated here; now required during boot.
/var Files that can change dynamically (log files, mail, and spool files)

Common Directories with Own Partition

It is common to mount the following directories onto their own partition:

Directory Reason
/ isolate the core OS away from the rest of the system
/boot isolate kernel boot images, cannot be LVM
/home isolate user data from the rest of the system; usually to allocate more storage space and preserve user data during upgrades
/tmp isolate world writeable /tmp to give more secure mount options
/var isolate other variable data that could grow from affecting the rest of the system. (yum cache, common place for applications to write to)
/var/log prevent run away log files from affecting the rest of the system

View Mounts

Different ways to see file system mounts.


The “findmnt” command shows a tree like mount structure.

[root@srv01 ~]# findmnt
TARGET                           SOURCE                                FSTYPE     OPTIONS
/                                /dev/mapper/vgroot-lvroot             xfs        rw,relatime,attr2,inode64,noquota
├─/proc                          proc                                  proc       rw,nosuid,nodev,noexec,relatime
│ └─/proc/sys/fs/binfmt_misc     systemd-1                             autofs     rw,relatime,fd=40,pgrp=1,timeout=300,minproto=5,maxproto=5,direct
├─/sys                           sysfs                                 sysfs      rw,nosuid,nodev,noexec,relatime
│ ├─/sys/kernel/security         securityfs                            securityfs rw,nosuid,nodev,noexec,relatime
│ ├─/sys/fs/cgroup               tmpfs                                 tmpfs      rw,nosuid,nodev,noexec,mode=755
│ │ ├─/sys/fs/cgroup/systemd     cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd
│ │ ├─/sys/fs/cgroup/cpuset      cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,cpuset
│ │ ├─/sys/fs/cgroup/cpu,cpuacct cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,cpuacct,cpu
│ │ ├─/sys/fs/cgroup/memory      cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,memory
│ │ ├─/sys/fs/cgroup/devices     cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,devices
│ │ ├─/sys/fs/cgroup/freezer     cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,freezer
│ │ ├─/sys/fs/cgroup/net_cls     cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,net_cls
│ │ ├─/sys/fs/cgroup/blkio       cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,blkio
│ │ ├─/sys/fs/cgroup/perf_event  cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,perf_event
│ │ └─/sys/fs/cgroup/hugetlb     cgroup                                cgroup     rw,nosuid,nodev,noexec,relatime,hugetlb
│ ├─/sys/fs/pstore               pstore                                pstore     rw,nosuid,nodev,noexec,relatime
│ ├─/sys/kernel/config           configfs                              configfs   rw,relatime
│ └─/sys/kernel/debug            debugfs                               debugfs    rw,relatime
├─/dev                           devtmpfs                              devtmpfs   rw,nosuid,size=1829904k,nr_inodes=457476,mode=755
│ ├─/dev/shm                     tmpfs                                 tmpfs      rw,nosuid,nodev
│ ├─/dev/pts                     devpts                                devpts     rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000
│ ├─/dev/mqueue                  mqueue                                mqueue     rw,relatime
│ └─/dev/hugepages               hugetlbfs                             hugetlbfs  rw,relatime
├─/run                           tmpfs                                 tmpfs      rw,nosuid,nodev,mode=755
├─/mnt/redusb                    /dev/mapper/vgredusb-lvredbackups     ext4       rw,relatime,data=ordered
├─/mnt/blackusb                  /dev/mapper/vgblackusb-lvblackbackups ext4       rw,relatime,data=ordered
├─/boot                          /dev/sda1                             xfs        rw,relatime,attr2,inode64,noquota
├─/tmp                           /dev/mapper/vgroot-lvtmp              xfs        rw,relatime,attr2,inode64,noquota
├─/home                          /dev/mapper/vgroot-lvhome             xfs        rw,relatime,attr2,inode64,noquota
└─/var                           /dev/mapper/vgroot-lvvar              xfs        rw,relatime,attr2,inode64,noquota

The “mount” command showing only xfs and ext4 file system types (-t xfs,ext4)

[root@srv01 ~]# mount -t xfs,ext4
/dev/mapper/vgroot-lvroot on / type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mapper/vgblackusb-lvblackbackups on /mnt/blackusb type ext4 (rw,relatime,data=ordered)
/dev/mapper/vgredusb-lvredbackups on /mnt/redusb type ext4 (rw,relatime,data=ordered)
/dev/mapper/vgroot-lvtmp on /tmp type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mapper/vgroot-lvhome on /home type xfs (rw,relatime,attr2,inode64,noquota)
/dev/mapper/vgroot-lvvar on /var type xfs (rw,relatime,attr2,inode64,noquota)
/dev/sda1 on /boot type xfs (rw,relatime,attr2,inode64,noquota)

“df” command with human readable (-h) and print file system type (-T):

[root@srv01 ~]# df -hT
Filesystem                            Type      Size  Used Avail Use% Mounted on
/dev/mapper/vgroot-lvroot             xfs        30G  1.9G   29G   7% /
devtmpfs                              devtmpfs  1.8G     0  1.8G   0% /dev
tmpfs                                 tmpfs     1.8G     0  1.8G   0% /dev/shm
tmpfs                                 tmpfs     1.8G  8.6M  1.8G   1% /run
tmpfs                                 tmpfs     1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/mapper/vgblackusb-lvblackbackups ext4       99G   65G   29G  70% /mnt/blackusb
/dev/mapper/vgredusb-lvredbackups     ext4       99G   66G   28G  71% /mnt/redusb
/dev/mapper/vgroot-lvtmp              xfs       8.0G   33M  8.0G   1% /tmp
/dev/mapper/vgroot-lvhome             xfs       100G   65G   36G  65% /home
/dev/mapper/vgroot-lvvar              xfs       8.0G  527M  7.5G   7% /var
/dev/sda1                             xfs       247M  164M   83M  67% /boot
  • linux_wiki/file_system_hierarchy.txt
  • Last modified: 2019/05/26 03:50
  • (external edit)