mkfs_vxfs(1M)

Do not write the file system to the special file. This option gives all the information needed to create a file system but does not create it.

Create a file system in a file. Used for debugging only.

bsize is the block size for files on the file system and represents the smallest amount of disk space allocated to a file. The value of bsize must be based on 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 Version 5 disk layout file systems larger than two terabytes, the maximum file system size is dependent on the block size. See the "VxFS Version 5 Disk Layout File System Sizes" topic in this section for more information. If bsize is not specified, the block size defaults are set to the appropriate value, based on size, when a file system is created.

n is the on-disk inode structure size for files on the file system. The valid values are 256 and 512 bytes. The default is 256. There is usually no reason to increase the inode size, and not using the default value can adversely affect file system performance.

Controls the largefiles flag for the file system. If largefiles is specified, the bit is set and files two gigabytes or larger can be created. If nolargefiles is specified, the bit is cleared and files created on the file system are limited to less than two gigabytes. The default is nolargefiles. See fsadm_vxfs(1M) and mkfs(1M).

If largefiles is not specified, and inosize is 256 the maximum number of inodes on the file system is approximately 8,380,000. If largefiles is not specified, and inosize is 512, the maximum number of inodes on the file system is approximately 4,190,000.

Note: Large files are supported on HP-UX 10.20 systems and above. Be careful when implementing large file system capability. System administration utilities such as backup may not operate correctly if they are not large-file aware.

n is the number of file system blocks to allocate for an activity logging area. The minimum value for the Version 4 and Version 5 disk layout is the number of blocks that make the log no less than 256K. The maximum value for n is the number of blocks that make the log no greater than 16384K. The default logsize is 16 megabytes for file systems that are are 512 megabytes or larger. 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, and NFS-intensive workload performs better with a large log; a small floppy device requires a small log.

Note: The amount of virtual memory required by fsck (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 16384K log can be cleaned. On small systems, take care 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 rule of thumb (see swapinfo(1M)).

n is the maximum number of inodes in the file system. The actual maximum number of inodes is n rounded up to an appropriate boundary. The digit 0 and the string unlimited both mean that the number of inodes is unlimited. The default is unlimited.

n is the VxFS disk layout version number. Valid values are 4 and 5. The default is disk layout Version 5. The Version 5 disk layout supports file systems up to 32 terabytes in size.