| .TH MKFS.CRAMFS 8 "April 2013" "util-linux" "System Administration" |
| .SH NAME |
| mkfs.cramfs \- make compressed ROM file system |
| .SH SYNOPSIS |
| .B mkfs.cramfs |
| [options] |
| .I directory file |
| .SH DESCRIPTION |
| Files on cramfs file systems are zlib-compressed one page at a time to |
| allow random read access. The metadata is not compressed, but is |
| expressed in a terse representation that is more space-efficient than |
| conventional file systems. |
| .PP |
| The file system is intentionally read-only to simplify its design; random |
| write access for compressed files is difficult to implement. cramfs |
| ships with a utility (mkcramfs) to pack files into new cramfs images. |
| .PP |
| File sizes are limited to less than 16\ MB. |
| .PP |
| Maximum file system size is a little under 272\ MB. (The last file on the |
| file system must begin before the 256\ MB block, but can extend past it.) |
| .SH ARGUMENTS |
| The |
| .I directory |
| is simply the root of the directory tree that we want to generate a |
| compressed filesystem out of. |
| .PP |
| The |
| .I file |
| will contain the cram file system, which later can be mounted. |
| .SH OPTIONS |
| .TP |
| \fB\-v\fR |
| Enable verbose messaging. |
| .TP |
| \fB\-E\fR |
| Treat all warnings as errors, which are reflected as command return value. |
| .TP |
| \fB\-b\fR \fIblocksize\fR |
| Use defined block size, which has to be divisible by page size. |
| .TP |
| \fB\-e\fR \fIedition\fR |
| Use defined file system edition number in superblock. |
| .TP |
| \fB\-N\fR \fIbig, little, host\fR |
| Use defined endianness. Value defaults to |
| .IR host . |
| .TP |
| \fB\-i\fR \fIfile\fR |
| Insert a |
| .I file |
| to cramfs file system. |
| .TP |
| \fB\-n\fR \fIname\fR |
| Set name of the cramfs file system. |
| .TP |
| \fB\-p\fR |
| Pad by 512 bytes for boot code. |
| .TP |
| \fB\-s\fR |
| This option is ignored. Originally the \-s turned on directory entry |
| sorting. |
| .TP |
| \fB\-z\fR |
| Make explicit holes. Use of this option will require 2.3.39 kernel, or newer. |
| .TP |
| \fB\-V\fR |
| Display version information and exit. |
| .TP |
| \fB\-h\fR |
| Display help and exit. |
| .SH "EXIT STATUS" |
| .RS |
| .PD 0 |
| .TP |
| .B 0 |
| success |
| .TP |
| .B 8 |
| operation error, such as unable to allocate memory |
| .PD |
| .RE |
| .SH "SEE ALSO" |
| .BR mount (8), |
| .BR fsck.cramfs (8) |
| .SH AVAILABILITY |
| The example command is part of the util-linux package and is available from |
| .UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/ |
| Linux Kernel Archive |
| .UE . |
