| mkfs.erofs |
| |
| mkfs.erofs is a user-space tool to create erofs filesystem images. |
| |
| It can create 2 main types of erofs images, compressed and uncompressed: |
| - For compressed images, it is able to integrate several compression |
| algorithms, lz4 is supported according to the current erofs kernel |
| implementation. |
| - For uncompressed images, it can decide whether the last page of |
| a file should be inlined or not properly [1]. |
| |
| Note that mkfs.erofs can only be linked statically with lz4 library |
| due to the dependency of experimental lz4hc apis which were added in |
| lz4 1.8.0. Anyway, it's a good start to begin with building the latest |
| lz4 library statically first. :) |
| |
| Dependencies |
| lz4-1.8.0 or above |
| |
| How to build with lz4 static library |
| ./configure --with-lz4=<lz4 install path> |
| eg. if lz4 has been installed into fold of /usr/local |
| ./configure --with-lz4=/usr/local && make |
| On Fedora, static lz4 can be installed using: |
| yum install lz4-static.x86_64 |
| To build you should run this first: |
| $ ./autogen.sh |
| $ ./configure |
| $ make |
| |
| mkfs.erofs binary will be generated under mkfs folder. |
| |
| Usage: |
| $ ./mkfs.erofs |
| mkfs.erofs v1.0 Nov 17 2018 19:47:21 |
| |
| Usage: |
| [-z <compr_algri>] [-d <dbglvl>] |
| [target path] [source directory] |
| |
| -d -- set debugging level <dbglvl> |
| -z -- enable <compr_algri> compression (only lz4hc is supported) |
| |
| Target path, source directory are both needed. |
| |
| Specimen Usage: |
| 1) Create a temporary Disk |
| $ dd if=/dev/zero of=erofs_disk bs=512 count=23000 |
| |
| 2) Create and populate source directory |
| $ mkdir -p srcd |
| |
| Our sample source directory contents |
| $ ls -ali srcd/ |
| total 44 |
| 425555 drwxr-xr-x 2 root root 4096 Feb 23 06:55 . |
| 425533 drwxr-xr-x 9 root root 4096 Feb 26 06:54 .. |
| 422789 -rw-r--r-- 1 root root 0 Feb 22 14:52 ChangeLog |
| +422793 -rw-r--r-- 1 root root 3195 Feb 23 06:55 configure.ac |
| +422794 -rw-r--r-- 1 root root 25763 Feb 23 06:55 Makefile |
| +422796 -rw-r--r-- 1 root root 1879 Feb 23 06:55 README |
| |
| 3) Run mkfs.erofs |
| ./mkfs/mkfs.erofs ./erofs_disk ./srcd/ |
| c_version: [0.1 Feb 22 2019 14:13:38] |
| c_img_path: [./erofs_disk] |
| c_src_path: [/root/arshad/erofs-utils/srcd] |
| c_dbg_lvl: [ 0] |
| c_dry_run: [ 0] |
| c_alg_name: [ none] |
| c_compr_maxsz: [ 921600] |
| c_compr_lvl: [ 0] |
| c_compr_boundary: [ 128] |
| c_compr_ratio_limit: [ 100] |
| |
| 4) Load erofs.ko module |
| $ insmod drivers/staging/erofs/erofs.ko |
| |
| 5) Mount erofs_disk image |
| $ mount -t erofs erofs_disk /mnt/vg1 -o loop |
| |
| 6) Check FS type mount reports |
| $ mount | grep erofs |
| /root/arshad/erofs-utils/erofs_disk on /mnt/vg1 type erofs ro,relatime,user_xattr,acl) |
| |
| 7) Check the contents of the mounted FS |
| $ ls -ali /mnt/vg1/ |
| total 31 |
| 4 -rw-r--r-- 1 root root 0 Feb 23 06:55 ChangeLog |
| 896 -rw-r--r-- 1 root root 3195 Feb 23 06:55 configure.ac |
| 5 -rw-r--r-- 1 root root 25763 Feb 23 06:55 Makefile |
| 44 -rw-r--r-- 1 root root 1879 Feb 23 06:55 README |
| |
| 8) Umount /mnt/vg1 |
| $ umount /mnt/vg1 |
| |
| 9) Unload erofs module |
| $ rmmod erofs |
| |
| To: |
| linux-erofs mailing list <linux-erofs@lists.ozlabs.org> |
| Li Guifu <bluce.liguifu@huawei.com> |
| Miao Xie <miaoxie@huawei.com> |
| Fang Wei <fangwei1@huawei.com> |
| |
| Thanks-to: |
| Sun Qiuyang <sunqiuyang@huawei.com> |
| Guo Xuenan <guoxuenan@huawei.com> |
| Du Wei <weidu.du@huawei.com> |
| Wang Zhigang <brooke.wangzhigang@hisilicon.com> |
| |
| [1] According to the erofs on-disk format, the last page of files could |
| be inlined aggressively with its metadata in order to reduce the I/O |
| overhead and save the storage space. |
| |
