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What's the right filesystem for your portable backup drive?
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NEWFS_MSDOS(8) BSD System Manager's Manual NEWFS_MSDOS(8) NAME
newfs_msdos -- construct a new MS-DOS (FAT) file system SYNOPSIS
newfs_msdos [-N] [-B boot] [-F FAT-type] [-I volid] [-O OEM] [-S sector-size] [-a FAT-size] [-b block-size] [-c cluster-size] [-e dirents] [-f format] [-h heads] [-i info] [-k backup] [-m media] [-n FATs] [-o hidden] [-r reserved] [-s total] [-u track-size] [-v volume-name] special [disktype] DESCRIPTION
The newfs_msdos utility creates a FAT12, FAT16, or FAT32 file system on device special, using disktab(5) entry disktype to determine geome- try, if required. The options are as follow: -N Don't create a file system: just print out parameters. -B boot Get bootstrap from file. -F FAT-type FAT type (one of 12, 16, or 32). -I volid Volume ID. -O OEM OEM string (up to 8 characters). The default is "BSD 4.4". -S sector-size Number of bytes per sector. Acceptable values are powers of 2 in the range 128 through 32768. -a FAT-size Number of sectors per FAT. -b block-size File system block size (bytes per cluster). This should resolve to an acceptable number of sectors per cluster (see below). -c cluster-size Sectors per cluster. Acceptable values are powers of 2 in the range 1 through 128. -e dirents Number of root directory entries (FAT12 and FAT16 only). -f format Specify a standard (floppy disk) format. The eight standard formats are (capacities in kilobytes): 160, 180, 320, 360, 640, 720, 1200, 1232, 1440, 2880. -h heads Number of drive heads. -i info Location of the file system info sector (FAT32 only). A value of 0xffff signifies no info sector. -k backup Location of the backup boot sector (FAT32 only). A value of 0xffff signifies no backup sector. -m media Media descriptor (acceptable range 0xf0 to 0xff). -n FATs Number of FATs. Acceptable values are 1 to 16 inclusive. The default is 2. -o hidden Number of hidden sectors. -r reserved Number of reserved sectors. -s total File system size. -u track-size Number of sectors per track. -v volume-name Volume name (filesystem name), up to 11 characters. The name should consist of only those characters permitted in regular DOS (8+3) filenames. NOTES
FAT file system parameters occupy a "Boot Sector BPB (BIOS Parameter Block)" in the first of the "reserved" sectors which precede the actual file system. For reference purposes, this structure is presented below. struct bsbpb { u_int16_t bps; /* [-S] bytes per sector */ u_int8_t spc; /* [-c] sectors per cluster */ u_int16_t res; /* [-r] reserved sectors */ u_int8_t nft; /* [-n] number of FATs */ u_int16_t rde; /* [-e] root directory entries */ u_int16_t sec; /* [-s] total sectors */ u_int8_t mid; /* [-m] media descriptor */ u_int16_t spf; /* [-a] sectors per FAT */ u_int16_t spt; /* [-u] sectors per track */ u_int16_t hds; /* [-h] drive heads */ u_int32_t hid; /* [-o] hidden sectors */ u_int32_t bsec; /* [-s] big total sectors */ }; /* FAT32 extensions */ struct bsxbpb { u_int32_t bspf; /* [-a] big sectors per FAT */ u_int16_t xflg; /* control flags */ u_int16_t vers; /* file system version */ u_int32_t rdcl; /* root directory start cluster */ u_int16_t infs; /* [-i] file system info sector */ u_int16_t bkbs; /* [-k] backup boot sector */ }; EXAMPLES
newfs_msdos /dev/disk0s1 Create a file system, using default parameters, on /dev/disk0s1. newfs_msdos -f 1440 -v foo fd0 Create a standard 1.44M file system, with volume name "foo", on /dev/fd0. SEE ALSO
fdisk(8), mount(8) DIAGNOSTICS
Exit status is 0 on success and 1 on error. HISTORY
The newfs_msdos command appeared in FreeBSD 3.0. AUTHORS
Robert Nordier <rnordier@FreeBSD.org>. BSD
July 6, 1998 BSD
