sgdiag(8)
NAME
sgdiag - Do Diagnostic functions on SCSI devices
SYNOPSIS
sgdiag [-aenx]
DESCRIPTION
Sgdiag is a program that uses the SCSI Generic interface
to send specific SCSI commands to specified SCSI devices.
The SCSI Generic interface requires that the kernel .con
fig file have CONFIG_CHR_DEV_SG set.
A log file, named sgdiag.log is created in the /var/log
directory which logs the status of the functions and any
errors.
Several different functions can be performed with this
utility.
- c = Compose Command to send
- This function allows the user to compose a custom
SCSI command to send to one or more devices. It
prompts the user for the command length, each com
mand byte, the write data length, each write data
byte, and the receive data length. - r = Reset SCSI bus
- This function will send a bus reset signal to the
SCSI bus of the selected device. This may be use
ful to free up a hung device. - i = Special Ser# Inquiries
- This issues several special SCSI inquiry to obtain
the serial number of the device. Normally this is
not needed, since the serial number of most modern
devices is included in the standard inquiry. - f = Format SCSI disk
- This function issues a low-level SCSI format com
mand to the selected device. This will remap any
media defects as it formats the disk. Of course,
it will erase any data on the selected disk. - w = Wipe SCSI disk
- This function issues a low-level SCSI format com
mand to the selected device. This will NOT include
the previous grown defect list. This may be useful
in testing to cause a disk to expose some media
defects. This is dangerous and should not be used
on production systems. - d = Send Diagnostic self-test
- This function issues a SCSI Send Diagnostic selftest command to the selected device. The device
returns a sense error if the self-test does not
succeed. - s = Start Unit
- This function issues a SCSI Start Unit command.
Some disk drives may not be configured to automati
cally start after power up. A reported sense of
02-04-02 indicates that this command is needed. - t = Stop Unit
- This function issues a SCSI Stop Unit command.
This might be used in testing to simulate a device
failure. - 1 = Do bug 1 (sense_len = 18)
- The standard sg structure only defines 16 bytes of
sense data, whereas 18 bytes are needed to parse
some illegal request sense keys. This function
attempts to request 18 bytes of sense data from the
standard sg structure, which should cause a 5/24/00
sense error, but should not cause the driver or the
utility to hang or stop working. - 2 = Do bug 2 (INQ hang)
- In versions of the old adaptec driver that were
delivered with RedHat 6.2, this function will hang
the driver by requesting a receive buffer less than
96 bytes. Newer versions of the driver should han
dle this function without error (status = 0). - 3 = Do bug 3 (format w short timeout)
- A SCSI format command can take several minutes to
complete. If the SCSI timeout is set too short, it
should cause several retries, followed by marking
the SCSI device offline. The device should return
to normal after a reboot.
OPTIONS
Command line options are described below.
- -? This option displays a summary of the commands
- accepted by sgdiag
- -a Automatically send command for all devices. If
- this option is specified, a default illegal SCSI
LOG_SENSE command will be sent to each device. - -e Causes any file writes to be avoided, such as the
- log file.
- -n Naming. By default, the device names are displayed
- as numeric sequences (/dev/sg0). This option shows
the device names as alphabetic sequences
(/dev/sga). - -x Causes extra debug messages to be displayed.
SEE ALSO
sgdefects(8) sgdskfl(8) sgmode(8)
WARNINGS
On some systems with older scsi drivers, the primary
defect list cannot be returned without errors.
See http://scsirastools.sourceforge.net for a bug list and
any later versions of this utility.
COPYRIGHT
Copyright (C) 2001-2002 Intel Corp.
sgdiag is open source software. You can redistribute it
and/or modify it under the terms of the BSD License. See
the COPYING file included with this software package for
more details regarding distribution.
sgdiag is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY.
AUTHOR
- Andy Cress <arcress@users.sourceforge.net>