mkfs_vxfs(1M) mkfs_vxfs(1M)
NAME
mkfs_vxfs: mkfs - construct a VxFS file system
SYNOPSIS
[generic_options] specific_options] special [size]
DESCRIPTION
The command constructs a file system by writing on the special device file (for example, unless the flag is provided. special specifies
the special device file location (or character device node) of a particular storage device. The numeric size specifies the number of
1024-byte sectors in the file system. If size is not specified, determines the size of the special device.
size can also be specified with a suffix to indicate a unit of measure other than sectors. Append to indicate the value is in kilobytes;
to indicate megabytes; to indicate gigabytes; or to indicate terabytes. An appended letter can be separated from the number by a spac by
enclosing the letter and number in a set of quotes (for example, "512 k").
The command builds a file system with a root directory and a lost+found directory (see fsck(1M)). The file system can have disk layout
Version 4, Version 5, or Version 6. Version 4 adds support for large files and Access Control Lists. Version 5 adds support for 32 ter-
abyte file systems. Version 6 adds support for 256 terabyte file systems and various extended VxFS features such as multi-volume support
and cross-platform data sharing. The default is Version 6.
The number of inodes allocated to a file system depends on the disk layout version. Inodes are allocated dynamically. There are a minimum
number of inodes allocated to the file system by and any other inode allocations are done on an as-needed basis during file system use.
NOTES
The size argument is ignored when the volume is part of a volume set. The full size of each volume is used instead.
The output of the option is not sufficient to recreate a multi-volume file system. The command fails if the option's output is used for
this purpose.
OPTIONS
generic_options
Supported by the generic command (see mkfs(1M)).
Specifies the VxFS file system type.
Displays the command line that was used to create the file system.
The file system must already exist. This option also enables you to determine the parameters used to construct the file system.
Echoes the completed command line, but does not perform the action.
The command line is generated by incorporating the specified options and arguments with other information derived from This
option allows the user to verify the command line.
Specifies the VxFS-specific
options in a comma-separated list.
The arguments and are no longer supported. The following arguments are available:
Do not write the file system to the
special file. Using gives all the information needed to create a file system but does not create it.
Creates a file system in a file.
Used for debugging only; size must be specified.
bsize
is the block size for files on the file system and represents the smallest amount of disk space allocated to a file. bsize
must be a power of 2 selected from the range 1024 bytes to 8192 bytes. The default is 1024 bytes for file systems smaller
than two terabytes. For file systems larger than two terabytes, the maximum file system size is dependent on the block
size. A block size of 1 KB allows a maximum file system size of up to 32 terabytes, a block size of 2 KB allows a maximum
file system size of up to 64 terabytes, a block size of 4 KB allows a maximum file system size of up to 128 terabytes, and a
block size of 8 KB allows for a file system up to 256 terabytes. These maximum sizes are for disk layout Version 6. The
actual maximum file system sizes are slightly less than the above values. The exact values can be found in the Veritas File
System Administrator's Guide. If bsize is not specified, the block size defaults to the appropriate value when a file sys-
tem is created.
inosize
is the on-disk inode structure size for files on the file system. The valid values are 256 and 512. The default is 256.
There is generally no reason to increase the inode size, and not using the default value can adversely affect file system
performance.
Controls the
flag for the file system. If is specified, the bit is set and files two gigabytes or larger can be created. If is speci-
fied, the bit is cleared and files created on the file system are limited to less than two gigabytes. The default is
mkfs(1M) and fsadm_vxfs(1M)).
VxFS file systems are created by default with the option enabled. Be sure that any system administration utilities used on
VxFS file systems, such as backup, operate on large files.
n is the number of file system blocks to allocate for an activity logging area. The minimum value is the number of blocks
that make the log no less than 256 KB. The maximum value for n is the number of blocks that make the log no greater than
262,144 kilobytes (256 MB) on a file system with disk layout Version 6, or 16,384 kilobytes (16 MB) on a file system with
disk layout Version 4 or 5. For a small file system, the default may be smaller to avoid wasting space.
A large log provides better performance on metadata-intensive workloads. A small log uses less space on the disk and leaves
more room for file data. For example, an NFS-intensive workload performs better with a large log; a small floppy device
requires a small log.
The amount of virtual memory required by (see fsck_vxfs(1M)) to check a VxFS file system is proportional to the size of the
log. The maximum amount of virtual memory used is twice the size of the log. Therefore, the sum of physical memory and
swap space must be at least 32 MB to ensure that a file system with a 16384 KB log can be cleaned. On small systems, be
careful not to create a file system with a log larger than half the available swap space. A maximum log size of one third
the total of memory and swap space is a good general rule. See swapinfo(1M).
n is the VxFS disk layout version number. Valid values are 4, 5, and 6. Version 6 disk layouts support file systems up to
256 terabytes in size, although file systems currently cannot be created with a size of 8 exabytes. The default is disk
layout Version 6.
EXAMPLES
Create a VxFS file system on Veritas Volume Manager volume at the special device file /dev/vx/rdsk/dg1/vol1 with a size of 1 GB.
Determine the block size, disk layout version, inode size, log size, and device size of a VxFS file system.
SEE ALSO
fsadm_vxfs(1M), fsck(1M), fsck_vxfs(1M), mkfs(1M), mount_vxfs(1M), swapinfo(1M), dir(4), fs_vxfs(4).
Veritas Volume Manager Administrator's Guide
mkfs_vxfs(1M)