OS Manuals

/usr/bin/mount.composefs

The reliability of disk images, the flexibility of files

From composefs 1.0.8-r11 (enterprise-packages), captured 2026-11-08 by running mount.composefs --help (exit 1). permalink

/usr/bin/mount.composefs: invalid option -- '-'
usage: mount.composefs [-t type] [-o opt[,opts..]] IMAGE MOUNTPOINT
Example:
  mount.composefs -o basedir=/composefs/objects exampleimage.cfs /mnt/exampleimage
or, as a mount helper:
  mount -t composefs -o basedir=/composefs/objects exampleimage.cfs /mnt/exampleimage

Supported options:
  basedir=PATH[:PATH]    Specify location of basedir(s)
  digest=DIGEST          Specify required image digest
  idmap=PATH             Specify path to a user namespace whose ID mapping should be used
  verity                 Require all files to have specified and valid fs-verity digests
  tryverity              If supported by kernel, require fs-verity
  ro                     Read only
  rw                     Read/write
  upperdir               Overlayfs upperdir
  workdir                Overlayfs workdir

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.