Linux NTFS support

= Background = For a long time, only reading a NTFS partition was available in Linux. It is a limitation for NAS devices as it means that a plugged USB drive that is in NTFS format will not be able in the network to store/modify data on this drive ! But there are, now, some solutions to gain write access to NTFS partitions. We will list the available solutions and benchmark them ...

= Available solutions =

Stock kernel's NTFS support (all platforms)
The NTFS support that is in the Linux kernel is only allowing read operations on NTFS disk.

Mounting a partition can be done using this command : mount -t ntfs /dev/'device' mountpoint

FUSE + NTFS-3G (all platforms)
This solution is the easiest to install, and is available for MIPS, PPC & ARM devices !

You need to compile the fuse support in your kernel and to compile Fuse and NTFS-3G.

Mounting a partition can be done using this command : mount -t ntfs-3g /dev/'device' mountpoint

Paragon Software NTFS for Linux (ARM only)
This solution have been developed by Paragon Software.

The ARM version is not publicly available and I had to sign a NDA to receive the module for benchmarking. The source code is not available but the driver have been compiled for a Marvell CPU close to the one used in our ARM9 devices. The point in testing that is to show if this solution is fast enought to be embedeed in a NAS device like the Linkstation Pro (and other NAS using the same Marvell's SoC).

It's have been compiled for a 2.6.12.6-arm1 kernel (same as the Linkstation stock kernel) but require some modules that are not in the stock Linkstation Pro system. The tested driver is : UFSD version 6.02 (Oct 4 2007, 16:33:44) NTFS read/write support included $Id: ufsdvfs.c,v 1.117 2007/09/17 14:38:11 shura Exp $

Mounting a partition can be done using this command : mount -t ufsd /dev/'device' mountpoint

= Benchmarking results = A Kurobox Pro (running @ 400MHz) and Bonnie++ v1.03a benchmarking tool have been used to benchmark the filesystems.
 * EXT3 benchmarking have been done using a 2.6.24-rc3 (Orion) kernel
 * FUSE v2.7.1 + NTFS-3G v1.1120 benchmarking have been done using a 2.6.24-rc3 (Orion) kernel
 * NTFS-3G v1.1128 benchmarking have been done using a 2.6.24-rc3 (Orion) kernel
 * Paragon Software NTFS for Linux driver (marvell_ufsd_slow.ko) benchmarking have been done using kernel 2.6.12.6

= Conclusion = Fuse + NTFS-3G give some slow performances on a Linkstation Pro/Kurobox Pro (and it should be worst on PPC based devices). In real usage configuration (ie : using an USB drive in NTFS format), performances will even be slower because of the USB driver taking CPU time ... We'll have to wait for this driver to be in optimization phase to have decent writing speed !

The Paragon Software driver is 2x faster than ntfs-3g for reading data and 7.5x faster for writing data. It's a commercial product that is perfect for NAS builders who want to add efficient NTFS support in their NAS, but for communities like ours, it's useless (because it's not available for individual persons and because it's linked to a specific kernel version).