mkfs_vxfs: mkfs - construct a VxFS file system
[generic_options] specific_options] special [size]
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
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 terabyte file sys‐
tems. 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.
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
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
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.
is the block size for files on the file system and rep‐
resents 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 ter‐
abytes, and a block size of 8 KB allows for a file sys‐
tem 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
system is created.
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.
flag for the file system. If is specified, the bit is
set and files two gigabytes or larger can be created.
If is specified, 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 utili‐
ties 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 kilo‐
bytes (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 propor‐
tional 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 sys‐
tems currently cannot be created with a size of 8
exabytes. The default is disk layout Version 6.
Create a VxFS file system on Veritas Volume Manager volume at the spe‐
cial 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 ALSOfsadm_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