NAME

newfs − construct a new ufs file system

SYNOPSIS

newfs [ −Nv ] [ mkfs-options ] raw-device

DESCRIPTION

newfs is a “friendly” front-end to the mkfs(1M) program for making ufs file systems on disk partitions.  newfs calculates the appropriate parameters to use and calls mkfs. 

raw-device is the name of a raw special device residing in /dev/rdsk (for example, /dev/rdsk/c0t0d0s6) on which to create the file system. 

If you run newfs interactively (that is, standard input is a tty), newfs will prompt for confirmation before making the file system. 

Note: You must be super-user to use this command. 

OPTIONS

−N Print out the file system parameters that would be used in creating the file system without actually creating the file system. 

−v Verbose.  newfs prints out its actions, including the parameters passed to mkfs. 

mkfs-options Options that override the default parameters are:

−a apc The number of alternate blocks per cylinder (SCSI devices only) to reserve for bad block replacement.  The default is 0. 

−b bsize The logical block size of the file system in bytes (either 4096 or 8192).  The default is 8192. 

−c cgize The number of cylinders per cylinder group (ranging from 1 to 32). The default is 16. 

−d gap Rotational delay. The expected time (in milliseconds) to service a transfer completion interrupt and initiate a new transfer on the same disk.  It is used to decide how much rotational spacing to place between successive blocks in a file. This parameter can be subsequently changed using the tunefs(1M) command. The default is disk-type dependent. 

−f fragsize The smallest amount of disk space in bytes to allocate to a file. The values must be a power of two selected from the range 512 to the logical block size.  If logical block size is 4096, legal values are 512, 1024, 2048 and 4096; if logical block size is 8192, 8192 is also a legal value.  The default is 1024. 

−i nbpi The number of bytes per inode. This  specifies the density of inodes in the file system.  The number is divided into the total size of the file system to determine the fixed number of inodes to create.  It should reflect the expected average size of files in the file system.  If fewer inodes are desired, a larger number should be used; to create more inodes a smaller number should be given. The default is 2048. 

−m free The minimum percentage of free space to maintain in the file system. This space is off-limits to normal users.  Once the file system is filled to this threshold, only the super-user can continue writing to the file system.  This parameter can be subsequently changed using the tunefs(1M) command. The default is 10%. 

−n nrpos The number of different rotational positions in which to divide a cylinder group. The default is 8. 

−o opt (space or time).  The file system can either be instructed to try to minimize the time spent allocating blocks, or to try to minimize the space fragmentation on the disk.  If the minimum free space threshold (as specified by the −m option) is less than 10%, the default is to optimize for space; if the minimum free space threshold is greater than or equal to 10%, the default is to optimize for time. 

−r rpm The speed of the disk in revolutions per minute.  The default is 3600. 

−s size The size of the file system in sectors.  The default is to use the entire partition. 

−t ntrack The number of tracks per cylinders on the disk.  The default is taken from the disk label. 

−C maxcontig The maximum number of blocks, belonging to one file, that will be allocated contiguously before inserting a rotational delay.  For a 4K file system, the default is 14; for an 8K file system, the default is 7.  This parameter can be subsequently changed using the tunefs(1M) command. 

Note: This parameter also controls clustering.  Regardless of  the  value of gap, clustering is enabled only when maxcontig is greater than 1.  Clustering allows higher I/O rates for sequential I/O and is described in tunefs(1M). 

EXAMPLES

The following example verbosely displays the parameters for the raw special device, c0t0d0s6, but does not actually create a new file system:

example# newfs −Nv /dev/rdsk/c0t0d0s6
mkfs −F ufs −o N /dev/rdsk/c0t0d0s6 1112940 54 15 8192 1024 16 10 60 2048 t 0 −1 8
/dev/rdsk/c0t0d0s6:     1112940 sectors in 1374 cylinders of 15 tracks, 54 sectors
        569.8MB in 86 cyl groups (16 c/g, 6.64MB/g, 3072 i/g)
super-block backups (for fsck −b #) at:
 32, 13056, 26080, 39104, 52128, 65152, 78176, 91200, 104224,
 ...
example#

SEE ALSO

fsck(1M), fsck_ufs(1M), mkfs(1M), mkfs_ufs(1M), tunefs(1M), fs_ufs(4)

DIAGNOSTICS

newfs: special No such file or directory
The device specified does not exist, or a disk partition was not specified.

special: cannot open
You must be super-user to use this command.

SunOS 5.2  —  Last change: 8 Mar 1993