Disks and File systems

File system types

HelenOS currently supports the following file systems:

File system	/srv executable	Can be root FS	Has mk*fs utility	Status
TMPFS	tmpfs	yes	no	Stable
FAT	fat	yes	yes	Stable
locfs	locfs	no	no	Stable
Ext2fs/Ext3fs/Ext4fs	ext4fs	yes	no	Stable
exFAT	exfat	no	yes	Testing
CDFS	cdfs	no	no	Testing
MFS	mfs	no	yes	Stable
UDF	udf	no	no	Read-only testing

Directory structure

The file system of a running HelenOS system is roughly laid out as follows:

/app	end-user applications (see the Command Reference)
/cfg	system-wide configuration
/data	application data (e.g. the web root served by websrv)
/drv	device drivers
/inc	header files
/lib	libraries
/loc	location service nodes (rough analogy of /dev in UNIX)
/src	source files
/srv	server applications (services, e.g. console, networking - see the Command Reference)
/tmp	temporary files

This layout is not fixed in any way and may change in the future.

Block device drivers

Non-DDF:

file_bd	File-backed block device
part	Disk label/partition driver - provides block devices for individual partitions
rd	Initial ramdisk
sata_bf	AHCI SATA

DDF-based:

ata_bd	ATA/ATAPI
usbmast	USB mass storage