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.

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

If the -N option is not specified and the inodes of the device are not randomized, newfs calls fsirand(1M).

You must be super-user to use this command, except when creating a UFS file system on a diskette. See EXAMPLES.

Creating a Multiterabyte UFS File System

The following options are supported:

-N

Print out the file system parameters that would be used in creating the file system without actually creating the file system. fsirand(1M) is not called here.

-T

Set the parameters of the file system to allow eventual growth to over a terabyte in total file system size. This option sets fragsize to be the same as bsize, and sets nbpi to 1 Mbyte, unless the -i option is used to make it even larger. If you use the -f or -i options to specify a fragsize or nbpi that is incompatible with this option, the user-supplied value of fragsize or nbpi is ignored.

Logging is enabled by default on all file systems created with this option.

-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 sectors per cylinder (SCSI devices only) to reserve for bad block replacement. The default is 0.

This option is not applicable for disks with EFI labels and is ignored.

-b bsize

The logical block size of the file system in bytes (either 4096 or 8192). The default is 8192. The sun4u architecture does not support the 4096 block size.

-c cgsize

The number of cylinders per cylinder group (ranging from 16 to 256). The default is calculated by dividing the number of sectors in the file system by the number of sectors in a gigabyte, and then multiplying the result by 32. The default value is always between 16 and 256. mkfs may override this value. See mkfs_ufs(1M) for details.

This option is not applicable for disks with EFI labels and is ignored.

-C maxcontig

The maximum number of logical blocks, belonging to one file, that is allocated contiguously before inserting a rotational delay. The default is determined from the disk drive's maximum transfer rate.

UFS supports no more than 1048576 byte (1MB) runs. With a logical block size of 4096, this gives a maxcontig limit of 256. With 8192, the limit is 128.

This parameter can be subsequently changed using the tunefs(1M) command.

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).

-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 zero, indicating a disk drive with track readahead buffering.

This option is not applicable for disks with EFI labels and is ignored.

-f fragsize

The smallest amount of disk space in bytes to allocate to a file. The smallest amout of disk space in bytes to allocate to a file. If the logical block size is 4096, legal values are 512, 1024, 2048, and 4096. When the logical block size is 8192, legal values are 1024, 2048, 4096, and 8192. The default value is 1024.

For file systems greater than 1 terabyte or for file systems created with the -T option, fragsize is forced to match block size (bsize).

-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 for nbpi is as follows:

Disk size Density Less than 1GB 2048 Less than 2GB 4096 Less than 3GB 6144 3GB to 1 Tbyte 8192 Greater than 1 Tbyte or created with -T 1048576

-m free

The minimum percentage of free space to maintain in the file system (between 1% and 99%, inclusively). 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 ((64 Mbytes/partition size) * 100), rounded down to the nearest integer and limited between 1% and 10%, inclusively.

-n nrpos

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

This option is not applicable for disks with EFI labels and is ignored.

-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. The default is time.

-r rpm

The speed of the disk in revolutions per minute. The default is driver- or device-specific.

This option is not applicable for disks with EFI labels and is ignored.

Note that you specify rpm for newfs and rps for mkfs.

-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 cylinder on the disk. The default is taken from the disk label.

This option is not applicable for disks with EFI labels and is ignored.

The following operands are supported:

raw-device

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

See largefile(5) for the description of the behavior of newfs when encountering files greater than or equal to 2 Gbyte ( 2³¹ bytes).

The following exit values are returned:

0

The operation was successful.

1, 10

Usage error or internal error. A message is output to STDERR explaining the error.

Other exit values may be returned by mkfs(1M), which is called by newfs.

See attributes(5) for descriptions of the following attributes:

fsck(1M), fsck_ufs(1M), fsirand(1M), mkfs(1M), mkfs_ufs(1M), tunefs(1M), attributes(5), largefile(5), ufs(7FS)

newfs: 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.