writing to FAT32 3112

In a message on 5 Mar 2005 14:06:59 -0800, wrote :

The Linux FAT drivers are very stable and reliable.

Floppies tend to be unreliable, especially given the way people handle them these days -- *no one* uses protective envelopes or cases anymore. Mounting with -t vfat *should* give read-write access by default. What *other* options are you using? What does youretc-fstab file have for your floppy drive? Mine is:

dev-fd0 fd0 msdos user,noauto,conv=auto,gid=100,uid=5125,umask=000 0 0dev-fd0 fd0v vfat user,noauto,conv=auto,gid=100,uid=5125,umask=000 0 0dev-fd0 fd0e2 ext2 user,noauto 0 0dev-fd0 fd0nc msdos user,noauto,gid=100,uid=5125,umask=000 0 0dev-fd0 fd0vnc vfat user,noauto,gid=100,uid=5125,umask=000 0 0dev-fd0D720 fd0ddnc msdos user,noauto,gid=100,uid=5125,umask=000 0 0dev-fd0D720 fd0dd msdos user,noauto,gid=100,uid=5125,umask=000 0 0dev-fd0fd0auto auto user,noauto,gid=100,uid=5125,umask=000 0 0

(yes, I have a pile of extra variations for various reasons.)

Also, MS-Windows users tend to do things that will corrupt floppies -- generally ejecting them without making sure the data is flushed. Linux *tries* to prevent this by locking the (removial) media on mount. Unfortunately, PC floppy drives are not mechanically 'lockable'. Since Linux uses a write-behind caching disk I-O system, ejecting a floppy while it is still mounted *will* result in file corruption. *Always* unmount the floppy before ejecting and *WAIT* for the disk I-O light to go out before pushing the eject button.

Mount it as '-t vfat'. Note, if you mount it as root and don't have the proper uid=, gid=, and umask= options it might appear to be read-only when it is not. Note: the chown & chgrp command *don't* work with fat and vfat file systems since these file system don't support file ownership.

The kernel won't let you mount a file system with the wrong file system type (or at least not with an incompatible file system). Specifing the wrong type will result in an error message ('wrong fs type or no super block'). There are several flavors of FAT: both in terms of the pointer size of the FAT itself (12-bit (floppies), 16-bit (small HD), and 32-bit (large HD)) and in terms of file naming (the original 8+3 names (msdos) and the 'long' names (vfat)). The FAT pointer size is auto-detected by the kernel. The file naming is selected as a option to mount. If you select the wrong file naming flavor, it is only inconvient: eg selecting the 8+3 flavor just means you will lots of foobar~1.dat files rather then foobarfile1.dat files. Selecting vfat on a disk without long names is harmless -- you will just get the short names, since that is all that is there.