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Manual Pages  — CFUMASS


cfumass – USB device side support for Mass Storage Class Transport



This driver can be compiled into the kernel by placing these lines in the kernel configuration file: device usb device usb_template device iscsi device ctl device cfumass

The driver module can also be loaded at boot by adding this line to loader.conf(5):



The cfumass driver provides device side support for emulating an USB mass storage device compliant with the USB Mass Storage Class Bulk-Only (BBB) Transport specification, implemented as a ctl(4) frontend driver.

To use cfumass:

Upon loading, the driver creates a ctl(4) port named cfumass, presenting the first LUN mapped for that port - usually LUN 0 - to the USB host. See ctl.conf(5) and ctld(8) for details on configuring the LUN.


These variables are available as both sysctl(8) variables and loader(8) tunables:
  Verbosity level for log messages from the cfumass driver. Set to 0 to disable logging or 1 to warn about potential problems. Larger values enable debugging output. Defaults to 1.
  Ignore START STOP UNIT SCSI commands with START and LOEJ bits cleared. Some initiators send that command to stop the target when the user attempts to gracefully eject the drive, but fail to start it when the drive is reconnected. Set to 0 to handle the command in a standards-compliant way, 1 to ignore it and log a warning, or 2 to ignore it silently. Defaults to 1.
  Max LUN number to report to the initiator (USB host). Must be between 0 and 15. Some initiators incorrectly handle values larger than 0. Defaults to 0.


ctl(4), umass(4), usb(4), usb_template(4), ctl.conf(5), ctld(8)


The cfumass driver first appeared in FreeBSD 11.1 .


The cfumass driver was developed by Edward Tomasz Napierala <Mt trasz@FreeBSD.org> under sponsorship from the FreeBSD Foundation.

CFUMASS (4) January 27, 2017

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