Essential System Administration, 3rd Edition

Filesystem Types

Before any disk partition can be used, a filesystem must be built on it. When a filesystem is made, certain data structures are written to disk that will be used to access and organize the physical disk space into files (see Section 10.3, later in this chapter).

Table 10-1 lists the most important filesystem types available on the various systems we are considering.

Table 10-1. Important filesystem types

Use	AIX	FreeBSD	HP-UX	Linux	Solaris	Tru64
Default local	jfs or jfs2	ufs	vxfs[1]	ext3, reiserfs	ufs	ufs or advfs
NFS	nfs	nfs	nfs	nfs	nfs	nfs
CD-ROM	cdrfs	cd9660	cdfs	iso9660	hsfs	cdfs
Swap	not needed	swap	swap, swapfs	swap	swap	not needed
DOS	not supported	msdos	not supported	msdos	pcfs	pcfs
/proc	procfs	procfs	not supported	procfs	procfs	procfs
RAM-based	not supported	mfs[2]	not supported	ramfs, tmpfs	tmpfs	mfs
Other		union	hfs	ext2	cachefs
[1] HP-UX defines the default filesystem type in /etc/default/fs’s LOCAL variable. [2] This feature is deprecated and will be replaced by the md facility in Version 5.

About Unix Filesystems: Moments from History

In the beginning was the System V filesystem. Well, not really, but that’s where we’ll start. This filesystem type once dominated System V-based operating systems.^[3]

The superblock of standard System V filesystems contained information about currently available free space in the filesystem in addition to information about how the space in the filesystem is allocated. It held the number of free inodes and data blocks, the first 50 free inode numbers, and the addresses of the first ...