Creating a UFS File System

You need to create UFS file systems only occasionally, because the system software automatically creates file systems as part of the installation process. You need to create (or re-create) a UFS file system when you:

• Add or replace disks

• Change the existing partitioning structure

• Do a full restoration on a file system

The following procedure uses the newfs command to create UFS file systems. The newfs command is a convenient front-end to the mkfs command, which creates the new file system. On Solaris 2.x systems, newfs parameter defaults, such as tracks per cylinder and sectors per track, are read from the disk label that will contain the new file system, and the options you choose are passed to the mkfs command to build the file system.

File System Parameters

To make a new file system on a disk slice, you almost always use the newfs command. Table 27-1 shows the default parameters the newfs command uses.

Prerequisites

• The disk must be formatted and divided into slices before you can create UFS file systems on it.

• You need to know the raw device file name of the slice that will contain the file system. See Chapter 22, Administering Disks (Tasks) for information on finding disks and disk slice numbers.

• If you are re-creating an existing UFS file system, unmount it.

• You must be superuser.

How to Create a UFS File System

1. Make sure you have met the prerequisites listed on "Prerequisites".

2. Create the file system.

   # newfs [-N] [-b size] [-i bytes] /dev/rdsk/device-name

   -N	Displays all of the parameters newfs would pass to mkfs. No file system is created.
   -b size	Sets the file system block size. Default is 8192 blocks.
   -i bytes	Sets the number of bytes per inode. Default is 2048 bytes.
   device-name	The device that will contain the new file system.

   ---

   Caution -

   Be sure you have specified the correct device name for the slice before performing the next step. If you specify the wrong slice, you will erase its contents when the new file system is created.

   ---

   The system asks for confirmation.

3. To verify the creation of UFS file systems, check the new file systems with the fsck command.

   # fsck /dev/rdsk/device-name

   device-name

   The name of the device containing the new file system.

   This utility checks the consistency of the new file system, reports problems it finds, and prompts you before repairing the problems. See Chapter 31, Checking File System Integrity for more information on fsck.

Example--Creating a UFS File System

This example creates a file system on /dev/rdsk/c0t3d0s7.

# newfs /dev/rdsk/c0t3d0s7
newfs: construct a new file system /dev/rdsk/c0t3d0s7 (y/n)? y
/dev/rdsk/c0t3d0s7:     163944 sectors in 506 cylinders of 9 tracks, 
   36 sectors 83.9MB in 32 cyl groups (16 c/g, 2.65MB/g, 1216 i/g)
super-block backups (for fsck -b #) at:
 32, 5264, 10496, 15728, 20960, 26192, 31424, 36656, 41888,
 47120, 52352, 57584, 62816, 68048, 73280, 78512, 82976, 88208,
 93440, 98672, 103904, 109136, 114368, 119600, 124832, 130064, 
 135296, 140528, 145760, 150992, 156224, 161456,

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