| .\" Copyright (c) 2019 Gao Xiang <xiang@kernel.org> |
| .\" |
| .TH MKFS.EROFS 1 |
| .SH NAME |
| mkfs.erofs \- tool to create an EROFS filesystem |
| .SH SYNOPSIS |
| \fBmkfs.erofs\fR [\fIOPTIONS\fR] \fIDESTINATION\fR \fISOURCE\fR |
| .SH DESCRIPTION |
| EROFS is a new enhanced lightweight linux read-only filesystem with modern |
| designs (eg. no buffer head, reduced metadata, inline xattrs/data, etc.) for |
| scenarios which need high-performance read-only requirements, e.g. Android OS |
| for smartphones and LIVECDs. |
| .PP |
| It also provides fixed-sized output compression support, which improves storage |
| density, keeps relatively higher compression ratios, which is more useful to |
| achieve high performance for embedded devices with limited memory since it has |
| unnoticable memory overhead and page cache thrashing. |
| .PP |
| mkfs.erofs is used to create such EROFS filesystem \fIDESTINATION\fR image file |
| from \fISOURCE\fR directory. |
| .SH OPTIONS |
| .TP |
| .BI "\-z " compression-algorithm " [" ",#" "]" |
| Set an algorithm for file compression, which can be set with an optional |
| compression level separated by a comma. |
| .TP |
| .BI "\-C " max-pcluster-size |
| Specify the maximum size of compress physical cluster in bytes. It may enable |
| big pcluster feature if needed (Linux v5.13+). |
| .TP |
| .BI "\-d " # |
| Specify the level of debugging messages. The default is 2, which shows basic |
| warning messages. |
| .TP |
| .BI "\-x " # |
| Specify the upper limit of an xattr which is still inlined. The default is 2. |
| Disable storing xattrs if < 0. |
| .TP |
| .BI "\-E " extended-option " [,...]" |
| Set extended options for the filesystem. Extended options are comma separated, |
| and may take an argument using the equals ('=') sign. |
| The following extended options are supported: |
| .RS 1.2i |
| .TP |
| .BI legacy-compress |
| Disable "decompression in-place" and "compacted indexes" support, which is used |
| when generating EROFS images for kernel version < 5.3. |
| .TP |
| .BI force-inode-compact |
| Forcely generate compact inodes (32-byte inodes) to output. |
| .TP |
| .BI force-inode-extended |
| Forcely generate extended inodes (64-byte inodes) to output. |
| .TP |
| .BI noinline_data |
| Don't inline regular files for FSDAX support (Linux v5.15+). |
| .TP |
| .BI force-inode-blockmap |
| Forcely generate inode chunk format in 4-byte block address array. |
| .TP |
| .BI force-chunk-indexes |
| Forcely generate inode chunk format in 8-byte chunk indexes (with device id). |
| .RE |
| .TP |
| .BI "\-T " # |
| Set all files to the given UNIX timestamp. Reproducible builds requires setting |
| all to a specific one. |
| .TP |
| .BI "\-U " UUID |
| Set the universally unique identifier (UUID) of the filesystem to |
| .IR UUID . |
| The format of the UUID is a series of hex digits separated by hyphens, |
| like this: "c1b9d5a2-f162-11cf-9ece-0020afc76f16". |
| .TP |
| .B \-\-all-root |
| Make all files owned by root. |
| .TP |
| .BI "\-\-blobdev " file |
| Specify another extra blob device to store chunk-based data. |
| .TP |
| .BI "\-\-chunksize " # |
| Generate chunk-based files with #-byte chunks. |
| .TP |
| .BI "\-\-compress-hints " file |
| If the optional |
| .BI "\-\-compress-hints " file |
| argument is given, |
| .B mkfs.erofs |
| uses it to apply the per-file compression strategy. Each line is defined by |
| tokens separated by spaces in the following form: |
| .RS 1.2i |
| <pcluster-in-bytes> <match-pattern> |
| .RE |
| .TP |
| .BI "\-\-exclude-path=" path |
| Ignore file that matches the exact literal path. |
| You may give multiple `--exclude-path' options. |
| .TP |
| .BI "\-\-exclude-regex=" regex |
| Ignore files that match the given regular expression. |
| You may give multiple `--exclude-regex` options. |
| .TP |
| .BI "\-\-file-contexts=" file |
| Specify a \fIfile_contexts\fR file to setup / override selinux labels. |
| .TP |
| .BI "\-\-force-uid=" UID |
| Set all file uids to \fIUID\fR. |
| .TP |
| .BI "\-\-force-gid=" GID |
| Set all file gids to \fIGID\fR. |
| .TP |
| .B \-\-help |
| Display this help and exit. |
| .TP |
| .BI "\-\-max-extent-bytes " # |
| Specify maximum decompressed extent size # in bytes. |
| .SH AUTHOR |
| This version of \fBmkfs.erofs\fR is written by Li Guifu <blucerlee@gmail.com>, |
| Miao Xie <miaoxie@huawei.com> and Gao Xiang <xiang@kernel.org> with |
| continuously improvements from others. |
| .PP |
| This manual page was written by Gao Xiang <xiang@kernel.org>. |
| .SH AVAILABILITY |
| \fBmkfs.erofs\fR is part of erofs-utils package and is available from |
| git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git. |
| .SH SEE ALSO |
| .BR mkfs (8). |
