Difference between mkfs.vfat and mkfs.msdos?

EmrldDrgn · 07-22-2009, 04:17 AM

I realize that both files are symlinks to mkdosfs, but does mkdosfs do any sort of check of the name it's called by, as I know some programs do? And if so, what is the difference between vfat and msdos? I mean, both create FAT file systems, right?

Tinkster · 07-22-2009, 04:32 AM

Which distro? There's no mkfs.vfat or mkfs.msdos in Slackware,
for example ...

shahz · 07-22-2009, 04:39 AM

in RHEL you will find the mkfs.vfat mkfs.msdos

IW2B · 07-22-2009, 05:21 AM

Hi,

The MSDOS file system will support the 8.3 file/directory naming, whereas vfat will allow you to use long file names.

The following is from my Fedora 11 system:

Code:

$ mkfs.vfat   /dev/sde1
$ mkfs.msdos  /dev/sde2

$ mount -t vfat  /dev/sde1 /vfat/
$ mount -t msdos /dev/sde2 /msdos/
$ mount
/dev/sde2 on /msdos type msdos (rw)
/dev/sde1 on /vfat type vfat (rw)


$ touch  /vfat/123456789.1234
$ touch /msdos/123456789.1234
$ ls -al /msdos/ /vfat/

/msdos/:
-rwxr-xr-x   1 user user    0 2009-07-22 12:16 12345678.123

/vfat/:
-rwxr-xr-x   1 user user    0 2009-07-22 12:16 123456789.1234

Regards
Ian

i92guboj · 07-22-2009, 05:32 AM

IW2B, that's due to how you mount the fs, and not because of the mkfs tool you use. In fact, you can quickly check that something formated with mkfs.msdos can be perfectly mounted as vfat because in fact both tools are the same.

Code:

$ dd if=/dev/zero of=foo.img bs=4096 count=10k
10240+0 records in
10240+0 records out
41943040 bytes (42 MB) copied, 0,0803099 s, 522 MB/s
$ mkfs.msdos foo.img
mkfs.msdos 3.0.2 (28 Feb 2009)
$ mkdir tmp
$ mount -t vfat -oloop foo.img tmp
$ mount|grep loop
/dev/loop0 on /home/i92guboj/tmp type vfat (rw)

EmrldDrgn, yes, both mkfs.vfat and mkfs.msdos are just symlinks pointing to mkdosfs, so they do exactly the same thing. mkdosfs supports fat12, 16 and 32 fs's but on a quick check of the source I haven't seen any specific check for the name of the argument zero, so both symlinks are equivalent unless I am missing something.

So, doing mkfs.msdos or mkfs.vfat makes no difference. However the driver for msdos and vfat on the kernel are not the same, so mounting them as msdos or vfat DO make a difference, because both drivers do have different capabilities.

I think that both symlinks exist just for convenience. Nothing else. They are 100% equivalent.

EmrldDrgn · 07-22-2009, 05:36 AM

Thank you very much, I understand now. That was my own estimation based on the source code, but I'm not familiar with Linux programming in C so I was afraid I may have missed something. I appreciate the help.

IW2B · 07-23-2009, 03:27 AM

hi i92guboj,

I knew that and looking back at my post I seem to have lost/deleted an entire paragraph regarding the mounting options after the code section!

Apologies for that

Ian