The lofi file driver exports a file as a block device. Reads and writes to the block device are translated to reads and writes on the underlying file. This is useful when the file contains a file system image. Exporting it as a block device through the lofi file driver allows normal system utilities to operate on the image through the block device (like fstyp(1M)fsck(1M), and mount(1M). This is useful for accessing CD-ROM and FAT floppy images. See lofiadm(1M) for examples.
File block device entries are contained in /dev/lofi, while /dev/rlofi contains the character (or raw) device entries. Entries are in the form of decimal numbers which are assigned through lofiadm(1M). When created, these device entries are owned by root, in group sys, and have permissions 0600. While ownership, group, and permission settings can be altered, there are possible ramifications. See lofiadm(1M) for more information.
Master control device
Block device for file n
Character device for file n
Driver configuration file. (Should not be altered.)
See attributes(5) for descriptions of the following attributes:
|ATTRIBUTE TYPE||ATTRIBUTE VALUE|
lofiadm(1M), fsck(1M), fstyp(1M), mount(1M), newfs(1M), attributes(5), lofs(7FS)
Just as you would not directly access a disk device that has mounted file systems, you should not access a file associated with a block device except through the lofi file driver.
For compatability purposes, a raw device is also exported along with the block device. For example, newfs(1M) requires one.