/proc/filesystems: Explanation & Insights

Information about supported filesystems

/proc/filesystems is a virtual file that provides information about the filesystems that are currently supported by the Linux kernel. Each supported filesystem has a corresponding entry in /proc/filesystems.

When you run the cat /proc/filesystems command, it will display a list of all the filesystems that the kernel supports, along with their type and other relevant information.

Here's an example output of the command:

nodev	sysfs
nodev	rootfs
nodev	ramfs
nodev	bdev
nodev	proc
nodev	cpuset
nodev	cgroup
nodev	cgroup2
nodev	tmpfs
nodev	devtmpfs
nodev	debugfs
nodev	tracefs
nodev	securityfs
nodev	sockfs
nodev	bpf
nodev	configfs
nodev	dax
nodev	hugetlbfs
nodev	zsmalloc
nodev	overlay
nodev	mnt-nfs

Each line represents a filesystem type. The first column specifies whether the filesystem is a block device (bdev) or a node device (nodev). The second column is the name of the filesystem.

For example, sysfs is a virtual filesystem that provides information about the system's hardware and software configuration. ramfs is a temporary filesystem that resides in memory, and proc is a virtual filesystem that provides information about running processes.

In summary, /proc/filesystems provides a convenient way to see the filesystems that are currently supported by the Linux kernel, and it can be useful when troubleshooting issues related to filesystems.