SCSI_LOGGING_LEVEL(8) SG3_UTILS SCSI_LOGGING_LEVEL(8)

scsi_logging_level - access Linux SCSI logging level information

scsi_logging_level [--all=LEV] [--create] [--error=LEV] [--get] [--help] [--highlevel=LEV] [--hlcomplete=LEV] [--hlqueue=LEV] [--ioctl=LEV] [--llcomplete=LEV] [--llqueue=LEV] [--lowlevel=LEV] [--midlevel=LEV] [--mlcomplete=LEV] [--mlqueue=LEV] [--scan=LEV] [--set] [--timeout=LEV] [--version]

This bash shell script accesses the Linux SCSI subsystem logging level. The current values can be shown (e.g. with --get) or changed (e.g. with --set). Superuser permissions will typically be required to set the logging level.

One of these options: --create, --get or --set is required. Only one of them can be given.

Arguments to long options are mandatory for short options as well.

LEV is used for all SCSI_LOG fields.
Options are parsed and placed in internal fields that are displayed but no logging levels are changed within the Linux kernel.
LEV is placed in the SCSI_LOG_ERROR field.
Fetches the current SCSI logging levels from the Linux kernel and displays them.
print out the usage message then exit.
LEV is placed in the SCSI_LOG_HLQUEUE and SCSI_LOG_HLCOMPLETE fields.
LEV is placed in the SCSI_LOG_HLCOMPLETE field.
LEV is placed in the SCSI_LOG_HLQUEUE field.
LEV is placed in the SCSI_LOG_IOCTL field.
LEV is placed in the SCSI_LOG_LLCOMPLETE field.
LEV is placed in the SCSI_LOG_LLQUEUE field.
LEV is placed in the SCSI_LOG_LLQUEUE and SCSI_LOG_LLCOMPLETE fields.
LEV is placed in the SCSI_LOG_MLQUEUE and SCSI_LOG_MLCOMPLETE fields.
LEV is placed in the SCSI_LOG_MLCOMPLETE field.
LEV is placed in the SCSI_LOG_MLQUEUE field.
LEV is placed in the SCSI_LOG_SCAN field.
Uses the fields specified in this command's options and attempts to apply them to the Linux SCSI subsystem logging levels. Typically superuser permissions will be required to do this.
LEV is placed in the SCSI_LOG_TIMEOUT field.
Outputs the version information and then exits.

The --get and --set options access the /proc/sys/dev/scsi/logging_level pseudo file.

The exit status of this script is 0 when it is successful. Any other exit status indicates that an error has occurred.

The following will set SCSI_LOG_ERROR to level 5 in the Linux kernel. It requires root permissions:


scsi_logging_level -s -E 5

So as to not interfere with other SCSI subsystem upper level drivers (ULDs) which most likely will be active at the same time, the Linux sg driver uses SCSI_LOG_TIMEOUT for logging purposes. To see full debugging and trace from the sg driver use:


scsi_logging_level -s -T 7

The output from the sg driver caused by this will go to the system logs (e.g. /var/log/syslog). To reduce the amount of output use a number lower than 7. Using 0 will turn off the tracing and debug.

To turn on maximum SCSI subsystem logging use:


scsi_logging_level -s -a 7

That is probably best done on a system that does not use a SCSI command device to hold the root file system, or the file system that holds the system log. Note that SATA disks and USB attached storage nearly always use the SCSI subsystem.

Written by IBM. Small alterations by Douglas Gilbert.

Report bugs to <dgilbert at interlog dot com>.

Copyright © IBM Corp. 2006
This software is distributed under the GPL version 2. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

The software was obtained from an IBM package called s390-tools-1.6.2 found on that company's "developerworks" site. The most recent version of that package at this time is 1.8.3 .

December 2022 sg3_utils-1.48