---
name: "umass"
section: "4"
platform: "linux"
package: "freebsd-manpages"
version: "6.0-5"
release: "Debian 4.0 (Etch)"
platforms: ["linux", "freebsd", "openbsd"]
url: "https://new.carta.tech/umass"
---

# umass(4)

USB Mass Storage Devices driver

## NAME

**umass** – USB Mass Storage Devices driver

## SYNOPSIS

**device umass**

## DESCRIPTION

The **umass** driver provides support for Mass Storage devices that attach to the USB port.

To use the **umass** driver, [usb(4)](/usb/4.md) and one of [uhci(4)](/uhci/4.md) or [ohci(4)](/ohci/4.md) must be configured in the kernel. Additionally, since **umass** uses the SCSI subsystem and sometimes acts as a SCSI device, it requires [da(4)](/da/4.md) and [scbus(4)](/scbus/4.md) to be included in the kernel.

## HARDWARE

The **umass** driver supports USB Mass Storage devices, including:

- ADTEC Stick Drive AD-UST32M, 64M, 128M, 256M

- Denno FireWire/USB2 Removable 2.5-inch HDD Case MIFU-25CB20

- FujiFilm Zip USB Drive ZDR100 USB A

- GREEN HOUSE USB Flash Memory "PicoDrive" GH-UFD32M, 64M, 128M

- IBM 32MB USB Memory Key (P/N 22P5296)

- IBM 256MB USB Drive (MSYSTEM DiskOnKey2)

- IBM ThinkPad USB Portable CD-ROM Drive (P/N 33L5151)

- I-O DATA USB CD/CD-R/CD-RW/DVD-R/DVD-RW/DVD-RAM/DVD-ROM Drive DVR-iUH2 (CDROM, DVD-RAM only)

- I-O DATA USB x6 CD-RW Drive CDRW-i64/USB (CDROM only)

- I-O DATA USB/IEEE1394 Portable HD Drive HDP-i30P/CI, HDP-i40P/CI

- Iomega USB Zip 100/250 drive

- Iomega Zip750 USB2.0 drive

- Keian USB1.1/2.0 3.5-inch HDD Case KU350A

- Kurouto Shikou USB 2.5-inch HDD Case GAWAP2.5PS-USB2.0

- LaCie P3 HardDrive USB 200GB

- Logitec LDR-H443U2 DVD-RAM/-R/+R/-RW/+RW drive

- Logitec Mobile USB Memory LMC-256UD

- Logitec USB1.1/2.0 HDD Unit SHD-E60U2

- Logitec USB Double-Speed Floppy Drive LFD-31U2

- Logitec USB/IEEE1394 DVD-RAM/R/RW Unit LDR-N21FU2 (CDROM only)

- MELCO USB Flash Disk "ClipDrive", RUF-C32M, -C64M, -C128M, -C256M, -C512M

- MELCO USB Flash Disk "PetitDrive", RUF-32M, -64M, -128M, -256Mm

- MELCO USB2.0 Flash Disk "PetitDrive2", RUF-256M/U2, -512M/U2

- MELCO USB2.0 MO Drive MO-CH640U2

- Matshita CF-VFDU03 floppy drive

- Microtech International, Inc. USB-SCSI-HD 50 USB to SCSI cable

- NOVAC USB2.0 2.5/3.5-inch HDD Case NV-HD351U

- PNY Attache Flash Drive

- Panasonic ("Matshita FDD CF-VFDU03")

- Panasonic KXL-CB20AN Portable DVD-ROM/CD-R/RW

- Panasonic KXL-CB35AN (DVD-ROM & CD-R/RW)

- Panasonic USB2.0 Portable CD-RW Drive KXL-RW40AN (CDROM only)

- Panasonic floppy drive

- RATOC Systems USB2.0 Removable HDD Case U2-MDK1, U2-MDK1B

- SanDisk SDDR-31 (Compact Flash)

- SanDisk SDDR-75 (only Compact Flash port works)

- Sitecom CN-300 MultiFlash (MMC/SD, SmartMedia, CF, MemoryStick)

- Sony Portable CD-R/RW Drive CRX10U (CDROM only)

- TEAC Portable USB CD-ROM Unit CD-110PU/210PU

- Trek Thumbdrive 8MB

- VAIO floppy drive (includes Y-E Data Flashbuster-U)

- Y-E Data floppy drive (720/1.44/2.88Mb)

Among the supported digital cameras are:

- Asahi Optical (PENTAX) Optio 230 & 330

## EXAMPLES

```
device umass
device scbus
device da
device pass
```

Add the **umass** driver to the kernel.

```
camcontrol rescan 0
```

Rescan a Zip drive that was added after boot. The command above assumes that the Zip drive is on the first SCSI bus in the system.

```
camcontrol rescan 0:0:0
camcontrol rescan 0:0:1
camcontrol rescan 0:0:2
camcontrol rescan 0:0:3
```

Rescan all slots on a multi-slot flash reader, where the slots map to separate LUNs on a single SCSI ID. Typically only the first slot will be enabled at boot time. Again, this assumes that the flash reader is the first SCSI bus in the system.

```
bsdlabel -w da0 zip100
newfs da0c
mount -t ufs /dev/da0c /mnt
```

Write a disklabel to the Zip drive (see [vpo(4)](/vpo/4.md) for the [disktab(5)](/disktab/5.md) entry), creates the file system and mounts the new file system on /mnt.

```
newfs_msdos /dev/da0
```

Create a new FAT type file system. Care should be taken not to run [newfs(8)](/newfs/8.md) on devices that already contain data, as this will result in the information being lost.

Many consumer devices such as digital cameras automatically create MS-DOS based file systems when storing information such as images and videos. These file systems can be accessed by specifying the file system type as **msdos** when using [mount(8)](/mount/8.md).

## SEE ALSO

[ehci(4)](/ehci/4.md), [ohci(4)](/ohci/4.md), [uhci(4)](/uhci/4.md), [usb(4)](/usb/4.md), [vpo(4)](/vpo/4.md), [disktab(5)](/disktab/5.md), [bsdlabel(8)](/bsdlabel/8.md), [camcontrol(8)](/camcontrol/8.md)

## AUTHORS

The **umass** driver was written by MAEKAWA Masahide ⟨bishop@rr.iij4u.or.jp⟩ and Nick Hibma ⟨n\_hibma@FreeBSD.org⟩.

This manual page was written by Nick Hibma ⟨n\_hibma@FreeBSD.org⟩.