scsa2usb(7D) Devices scsa2usb(7D)NAMEscsa2usb - SCSI to USB bridge driver
SYNOPSIS
storage@unit-address
DESCRIPTION
The scsa2usb driver is a USBA (Oracle Solaris USB architecture) compli‐
ant nexus driver that supports the USB Mass Storage Bulk Only Transport
Specification 1.0 and USB Control/Bulk/Interrupt (CBI) Transport Speci‐
fication 1.0. The scsa2usb driver also supports USB storage devices
that implement CBI Transport without the interrupt completion for sta‐
tus (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, bypass‐
ing 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 Oracle 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 rmformat(1) and volume manage‐
ment 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 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 can 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 overriding the default device
attributes. The entries in this list are commented out by default and
can be uncommented to enable support of particular devices.
Follow the information given in the scsa2usb.conf file to see if a par‐
ticular device can be supported using the override information. Also
see http://www.sun.com/io. For example, by adding the following to the
scsa2usb.conf file, many USB memory sticks and card readers might oper‐
ate more reliably:
attribute-override-list = "vid=* reduced-cmd-support=true";
Note that this override applies to all USB mass storage devices and
might be inappropriate for a USB CD writer. If so, you can add an entry
for each device to the attribute override 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 device as
described in the following subsection.
Using Volume Management
Disk storage devices are managed by Volume Manager. Software that man‐
ages removable media creates a device nickname that can be listed with
eject(1) or rmmount(1M). A device that is not mounted automatically can
be mounted using rmmount(1M) under /rmdisk/label. The mount(1M) and
umount(1M) commands do not accept nicknames; you must use explicit
device names with these commands.
See rmmount(1m) to unmount the device and eject(1) to eject the media.
If the device is ejected while it is mounted, volume management soft‐
ware unmounts the device before ejecting 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 device in /etc/vfstab. In
this entry, you must set the mount at boot field to no. See vfstab(4).
See the System Administration Guide, Volume I and Solaris Common Desk‐
top Environment: User's Guide for details on how to manage a removable
device with CDE and Removable Media Manager. See dtfile.1X under CDE
for information on how to use Removable Media Manager.
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 devices must follow the same
restrictions as those for SCSI disks or tapes. Refer to sd(7D) or
st(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
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 attributes:
┌─────────────────────────────┬──────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼──────────────────────────────┤
│Architecture │SPARC, x86, PCI-based systems │
├─────────────────────────────┼──────────────────────────────┤
│Availability │SUNWusb │
└─────────────────────────────┴──────────────────────────────┘
SEE ALSOcdrw(1), eject(1), rmformat(1), cfgadm_scsi(1M), cfgadm_usb(1M),
fdisk(1M), mount(1M), rmmount(1M), umount(1M), dtfile.1X (in CDE man
pages), 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
Universal Serial Bus Mass Storage Class Specification Overview 1.0
Universal Serial Bus Mass Storage Class Bulk-Only Transport Specifica‐
tion 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/io
DIAGNOSTICS
Refer to sd(7D) and st(7D).
In addition to being logged, the following messages can appear on the
system console. All messages are formatted in the following manner:
Warning: <device path> (scsa2usb<instance number>): Error Message...
Cannot access <device>. 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 dis‐
connect 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.
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 can be logged into the system log. They are for‐
matted in the following manner:
<device path><scsa2usb<instance number>): message...
Invalid <record> in scsa2usb.conf file entry.
An unrecognized record was specified in the scsa2usb.conf file.
Pkt submitted with 0 timeout which can 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 can be cor‐
rupted.
scsa2usb.conf override: <record>.
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
...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 Specifica‐
tion 1.0 and cannot be power managed. Power Management 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 takes place for the disk mass-storage device.
(Syncing is not supported by the scsa2usb driver.) As a result, the
file system on the media is not be consistent on reboot.
If a PCFS file system is mounted, no syncing is needed and the filesys‐
tem is consistent on reboot.
If a mass-storage device is busy, system suspend cannot proceed and the
system immediately resumes again.
Attempts to remove a mass-storage device from the system fails. The
failure is logged to the console. An attempt to replace the removed
device with some other USB device also fails. 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 can 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.
SunOS 5.10 17 May 2011 scsa2usb(7D)
