Devices scsa2usb(7D)
NAME
scsa2usb - SCSI to USB bridge driver
SYNOPSIS
storage@unit-address
DESCRIPTION
The scsa2usb driver is a USBA (Solaris USB architecture)
compliant nexus driver that supports the USB Mass Storage
Bulk Only Transport Specification 1.0 and USB
Control/Bulk/Interrupt (CBI) Transport Specification 1.0.
The scsa2usb driver also supports USB storage devices that
implement CBI Transport without the interrupt completion for
status (that is, Control/Bulk (CB) devices.) It supports
bus-powered and self-powered USB mass storage devices. This
nexus driver is both a USB client driver and a SCSA HBA
driver. As such, the scsa2usb driver only supports storage
devices that utilize the above two transports.
The scsa2usb driver also supports a ugen(7D) interface
allowing raw access to the device, for example by
libusb(3LIB) applications, bypassing the child sd(7D) or
st(7D) driver. Because a libusb application might change the
state of the device, you should not access the disk or tape
concurrently.
The scsa2usb nexus driver maps SCSA target driver requests
to USBA client driver requests.
The scsa2usb driver creates a child device info node for
each logical unit (LUN) on the mass storage device. The
standard Solaris SCSI disk driver or tape driver is attached
to those nodes. Refer to sd(7D) or st(7D).
This driver supports multiple LUN devices and creates a
separate child device info node for each LUN. All child LUN
nodes attach to sd(7D) for disks or st(7D) for tapes.
In previous releases, all USB disk storage devices were
treated as removable media devices and managed by rmfor-
mat(1) and volume management software. In the current
release, however, only disk storage devices with a removable
bit (RMB) value of 1 are removable. (The RMB is part of the
device's SCSI INQUIRY data.) See SCSI specifications
T10/995D Revision 11a, T10/1236-D Revision 20 or T10/1416-D
Revision 23 for more information. However, for backward
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Devices scsa2usb(7D)
compatibility, all USB disk storage devices can still be
managed by rmformat(1). With or without a volume manager,
you can mount, eject, hot remove and hot insert a 1394
mass storage device as the following sections explain.
Some devices may be supported by the USB mass storage driver
even though they do not identify themselves as compliant
with the USB mass storage class.
The scsa2usb.conf file contains an attribute-override-list
that lists the vendor ID, product ID, and revision for
matching mass storage devices, as well as fields for over-
riding the default device attributes. The entries in this
list are commented out by default and may be uncommented to
enable support of particular devices.
Follow the information given in the scsa2usb.conf file to
see if a particular device can be supported using the over-
ride information. Also see http://www.sun.com/io. For exam-
ple, by adding the following to the scsa2usb.conf file, many
USB memory sticks and card readers might operate more reli-
ably:
attribute-override-list = "vid=* reduced-cmd-support=true";
Note that this override applies to all USB mass storage dev-
ices and might be inappropriate for a USB CD writer. If so,
you can add an entry for each device to the attribute over-
ride list.
If USB mass storage support is considered a security risk,
this driver can be disabled in /etc/system as follows:
exclude: scsa2usb
Alternatively, you can disable automatic handling of a dev-
ice as described in the following subsection.
Using Volume Management
Disk storage devices are managed by Volume Manager. Software
that manages removable media creates a device nickname that
can be listed with eject(1) or rmmount(1). A device that is
not mounted automatically can be mounted using rmmount(1)
under /rmdisk/label. Note that the mount(1M) and mount(1M)
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Devices scsa2usb(7D)
commands do not accept nicknames; you must use explicit dev-
ice names with these commands.
See rmmount(1) to unmount the device and eject(1) to eject
the media. If the device is ejected while it is mounted,
volume management software unmounts the device before eject-
ing it. It also might kill any active applications that are
accessing the device.
Volume management software is hotplug-aware and normally
mounts file systems on USB mass storage devices if the file
system is recognized. Before hot removing the USB device,
use eject(1) to unmount the file system. After the device is
removed, a console warning, such as "The disconnected device
was busy, please reconnect," might display. The warning is
harmless and you can ignore it.
You can disable the automatic mounting and unmounting of
removable devices by inserting a entry for a removable dev-
ice in /etc/vfstab. In this entry, you must set the mount at
boot field to no. See vfstab(4). See the System Administra-
tion Guide, Volume I.
Using mount and umount
Use mount(1M) to explicitly mount the device and umount(1M)
to unmount the device. Use eject(1) to eject the media.
After you have explicitly mounted a removable device, you
cannot use a nickname as an argument to eject.
Removing the disk device while it is being accessed or
mounted fails with a console warning. To hot remove the disk
device from the system, unmount the file system, then kill
all applications accessing the device. Next, hot remove the
device. A storage device can be hot inserted at any time.
For a comprehensive listing of (non-bootable) USB mass-
storage devices that are compatible with this driver, see
www.sun.com/io.
DEVICE SPECIAL FILES
Disk block special file names are located in /dev/dsk, while
raw file names are located in /dev/rdsk. Tape raw file names
are located in /dev/rmt. Input/output requests to the dev-
ices must follow the same restrictions as those for SCSI
disks or tapes. Refer to sd(7D) or st(7D).
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Devices scsa2usb(7D)
IOCTLS
Refer to dkio(7I) and cdio(7I).
ERRORS
Refer to sd(7D) for disks or st(7D) for tapes.
FILES
The device special files for the USB mass storage device are
created like those for a SCSI disk or SCSI tape. Refer to
sd(7D) or st(7D).
/dev/dsk/cntndnsn
Block files for disks.
/dev/rdsk/cntndnsn
Raw files for disks.
/dev/usb/*/*/*
ugen(7D) nodes
/dev/rmt/[0- 127][l,m,h,u,c][b][n]
Raw files for tapes.
/vol/dev/aliases/zip0
Symbolic link to the character device for the media in
Zip drive 0
/vol/dev/aliases/jaz0
Symbolic link to the character device for the media in
Jaz drive 0.
/vol/dev/aliases/rmdisk0
Symbolic link to the character device for the media in
removable drive 0. This is a generic removable media
device.
/kernel/drv/scsa2usb
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Devices scsa2usb(7D)
32-bit x86 ELF kernel module
/kernel/drv/amd64/scsa2usb
64-bit x86 ELF kernel module
/kernel/drv/sparcv9/scsa2usb
64-bit SPARC ELF kernel module
/kernel/drv/scsa2usb.conf
Can be used to override specific characteristics.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
_____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|______________________________|
| Architecture | SPARC, x86, PCI-based systems|
|_____________________________|______________________________|
| Availability | driver/usb |
|_____________________________|______________________________|
SEE ALSO
cdrw(1), eject(1), rmformat(1), rmmount(1), cfgadm_scsi(1M),
cfgadm_usb(1M), fdisk(1M), mount(1M), umount(1M),
libusb(3LIB), scsi(4), vfstab(4), attributes(5),
ieee1394(7D)sd(7D), st(7D), ugen(7D), usba(7D), pcfs(7FS),
cdio(7I), dkio(7I)
Writing Device Drivers
System Administration Guide, Volume I
Solaris Common Desktop Environment: User's Guide
Universal Serial Bus Specification 2.0
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Devices scsa2usb(7D)
Universal Serial Bus Mass Storage Class Specification Over-
view 1.0
Universal Serial Bus Mass Storage Class Bulk-Only Transport
Specification 1.0
Universal Serial Bus Mass Storage Class
Control/Bulk/Interrupt (CBI) Transport Specification 1.0
System Administration Guide: Basic Administration
SCSI Specification T10/995D Revision 11a - March 1997
SCSI SpecificationT10/1236-D Revision 20 - July 2001
SCSI SpecificationT10/1416-D Revision 23- May 2005
http://www.sun.com
DIAGNOSTICS
Refer to sd(7D) and st(7D).
In addition to being logged, the following messages may
appear on the system console. All messages are formatted in
the following manner:
Warning: (scsa2usb): Error Message...
Cannot access . Please reconnect.
There was an error in accessing the mass-storage device
during reconnect. Please reconnect the device.
Device is not identical to the previous one on this port.
Please disconnect and reconnect.
Another USB device has been inserted on a port that was
connected to a mass-storage device. Please disconnect
the USB device and reconnect the mass-storage device
back into that port.
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Devices scsa2usb(7D)
Reinserted device is accessible again.
The mass-storage device that was hot-removed from its
USB slot has been re-inserted to the same slot and is
available for access.
Please disconnect and reconnect this device.
A hotplug of the device is needed before it can be
restored.
The following messages may be logged into the system log.
They are formatted in the following manner:
): message...
Invalid in scsa2usb.conf file entry.
An unrecognized record was specified in the
scsa2usb.conf file.
Pkt submitted with 0 timeout which may cause indefinite
hangs.
An application submitted a request but did not specify a
timeout.
Syncing not supported.
Syncing after a panic is not supported. The filesystem
may be corrupted.
scsa2usb.conf override: .
An override record specified in scsa2usb.conf was
applied. Examples of an override record applied to a
device with vendor ID 123 and product ID 456 are:
vid=0x123 pid=0x456 reduced-cmd-support=true
or
vid=* reduced-cmd-support=true
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Devices scsa2usb(7D)
...meaning that the override record is applied to this
device and all other USB mass storage devices.
NOTES
The Zip 100 drive does not comply with Universal Serial Bus
Specification 1.0 and cannot be power managed. Power Manage-
ment support for Zip 100 has been disabled.
If the system panics while a UFS file system is mounted on
the mass storage media, no syncing will take place for the
disk mass-storage device. (Syncing is not supported by the
scsa2usb driver.) As a result, the file system on the media
will not be consistent on reboot.
If a PCFS file system is mounted, no syncing is needed and
the filesystem will be consistent on reboot.
If a mass-storage device is busy, system suspend cannot
proceed and the system will immediately resume again.
Attempts to remove a mass-storage device from the system
will fail. The failure will be logged to the console. An
attempt to replace the removed device with some other USB
device will also fail. To successfully remove a USB mass-
storage device you must "close" all references to it.
An Iomega Zip 100Mb disk cannot be formatted on an Iomega
Zip250 drive. See the Iomega web site at
http://www.iomega.com for details.
Concurrent I/O to devices with multiple LUNs on the same
device is not supported.
Some USB CD-RW devices may perform inadequately at their
advertised speeds. To compensate, use USB CD-RW devices at
lower speeds (2X versus 4X). See cdrw(1) for details.
This driver also supports CBI devices that do not use USB
interrupt pipe for status completion.
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