freebsd-dev/share/man/man5/nandfs.5

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.Dd Nov 11, 2010
.Dt NANDFS 5
.Os
.Sh NAME
.Nm nandfs
.Nd NAND Flash file system
.Sh SYNOPSIS
To compile support for the
.Nm ,
place the following in your kernel configuration file:
.Bd -ragged -offset indent
.Cd "options NANDFS"
.Ed
.Pp
Even though the NAND FS can be used with any storage media, it has been
optimized and designed towards NAND Flash devices, so typically the following
driver is used:
.Bd -ragged -offset indent
.Cd "device nand"
.Ed
.Sh DESCRIPTION
The
.Nm
driver enables
.Fx
with support for NAND-oriented file system.
.Pp
It is a log-structured style file system with the following major features and
characteristics:
.Bl -bullet
.It
Hard links, symbolic links support
.It
Block journaling
.It
Copy-On-Write
.It
Snapshots (continuous, taken automatically, simultaneously mountable)
.It
Quick crash recovery at mount time
.It
64-bit data structures; supports many files, large files and volumes
.It
POSIX file permissions
.It
Checksum / ECC
.El
.Sh EXAMPLES
The most common usage is mounting the file system:
.Pp
.Dl "mount -t nandfs /dev/<gnandN> /mnt"
.Pp
or:
.Dl "mount_nandfs /dev/<gnandN> /mnt"
.Pp
where
.Ar gnandN
is the GEOM device representing a Flash partition (slice) containing the
.Nm
structure, and
.Pa /mnt
is a mount point.
.Pp
It is possible to define an entry in
.Pa /etc/fstab
for the
.Nm :
.Bd -literal
/dev/gnand0		/flash	nandfs		rw	0	0
.Ed
.Pp
This will mount a
.Nm
partition at the specified mount point during system boot.
.Sh SEE ALSO
.Xr gnand 4 ,
.Xr nand 4 ,
.Xr mount_nandfs 8 ,
.Xr nandfs 8 ,
.Xr nandsim 8 ,
.Xr nandtool 8 ,
.Xr umount_nandfs 8
.Sh HISTORY
The NAND FS concepts are based on NILFS principles and initial implementation
was derived from early read-only NILFS NetBSD code.
Since then the NAND FS
code diverged significantly and is by no means compatible with NILFS.
.Pp
The NAND Flash file system first appeared in
.Fx 10.0 .
.Sh AUTHORS
.An -nosplit
The NAND FS was written by
.An Grzegorz Bernacki
with the help of
.An Mateusz Guzik ,
based on the NetBSD code created by
.An Reinoud Zandijk .
Additional help and support by
.An Lukasz Plachno ,
.An Jan Sieka
and
.An Lukasz Wojcik .
This manual page was written by
.An Rafal Jaworowski .