procmounts

Procmounts refers to the /proc/mounts interface on Linux and other Unix-like systems. It is a read-only, kernel-provided file within the proc virtual filesystem that lists all currently mounted filesystems. The entry is updated in real time as devices are mounted or unmounted, and it serves as a canonical source of mount information for userspace tools.

Each line in /proc/mounts represents one mounted filesystem and contains six whitespace-separated fields: device, mountpoint, fstype, options, dump, and pass. The device field shows the block device or pseudo-device (for example, /dev/sda1 or tmpfs); the mountpoint is the directory where the filesystem is attached; the fstype is the filesystem type such as ext4, xfs, or tmpfs; the options field lists mount options separated by commas, for example rw,relatime,nosuid. The dump field is an integer used by the dump backup utility (commonly 0 or 1), and the pass field indicates the filesystem check order at boot (0 to disable, 1 for root, 2 for others).

Conventions: /proc/mounts is typically read by system utilities such as mount, df, and lsblk. On many systems, /etc/mtab is a symbolic link to /proc/mounts or is maintained to reflect the same information; this makes the data essentially consistent across tools.

Usage and considerations: Administrators and scripts read procmounts to determine what is mounted and how. Because it is kernel-provided, it shows the current state regardless of the user’s actions, and it should be consulted instead of static configuration files when diagnosing mount-related issues.