mount.erofs - Man Page

mount.erofs [Options] SOURCE MOUNTPOINT
mount.erofs -u TARGET
mount.erofs --reattach TARGET

EROFS is an enhanced lightweight read-only filesystem with modern designs for scenarios which need high-performance read-only requirements.

mount.erofs is used to mount an EROFS filesystem from SOURCE (which can be an image file or block device) to a MOUNTPOINT. It supports multiple backends including direct kernel mount, FUSE-based mount, and NBD (Network Block Device) for remote sources like OCI images.

-h,  --help

Display help message and exit.

-V,  --version

Display version information and exit.

-o options

Comma-separated list of mount options. See Mount Options below.

-t type[.subtype]

Specify the filesystem type and optional subtype. The type should be erofs. Available subtypes are:

fuse

Use FUSE-based mount via erofsfuse.

local

Force direct kernel mount (default if available).

nbd

Use NBD backend for remote sources (e.g., OCI images).

-u

Unmount the filesystem at the specified target.

--reattach

Reattach to an existing NBD device and restart the NBD service.

Standard mount options:

ro

Mount the filesystem read-only (default).

rw

Mount the filesystem read-write (not supported for EROFS).

nosuid

Do not honor set-user-ID and set-group-ID bits.

suid

Honor set-user-ID and set-group-ID bits (default).

nodev

Do not interpret character or block special devices.

dev

Interpret character or block special devices (default).

noexec

Do not allow direct execution of any binaries.

exec

Allow execution of binaries (default).

noatime

Do not update inode access times.

atime

Update inode access times (default).

nodiratime

Do not update directory inode access times.

diratime

Update directory inode access times (default).

relatime

Update inode access times relative to modify or change time.

norelatime

Do not use relative atime updates.

The following OCI-specific options are available:

oci.blob=digest

Specify the OCI blob digest to mount. The digest should be in the format sha256:.... Cannot be used together with oci.layer.

oci.layer=index

Specify the OCI layer index to mount (0-based). Cannot be used together with oci.blob.

oci.platform=platform

Specify the target platform (default: linux/amd64).

oci.username=username

Username for OCI registry authentication.

oci.password=password

Password for OCI registry authentication.

oci.tarindex=path

Path to a tarball index file for hybrid tar+OCI mode.

oci.zinfo=path

Path to a gzip zinfo file for random access to gzip-compressed tar layers.

oci.insecure

Use HTTP instead of HTTPS to access the image registry.

• EROFS filesystems are read-only by nature. The rw option will be ignored.
• When mounting OCI images via NBD, the mount process creates a background daemon to serve the NBD device. The daemon will automatically clean up when the filesystem is unmounted.
• The --reattach option is useful for recovering NBD mounts after a system crash or when the NBD daemon was terminated unexpectedly.
• Kernel direct mount is used when mounting a regular file without specifying a backend type. If file-based mounts is unsupported, loop devices will be set up automatically.

mkfs.erofs(1), erofsfuse(1), dump.erofs(1), fsck.erofs(1), mount(8), umount(8)

mount.erofs is part of erofs-utils.