raw device support
sg3_utils
-
Overview
--------
The device(s) used must meet one of two tests:
SCSI device:
Must appear in the output of 'sg_map'
+ (make sure the kernel module "sg" is loaded)
Raw device:
Must appear in the output of 'raw -qa'
-You may not mix raw and SCSI devices in the test specification.
+ If you need to create raw devices in order to use this tool, note that
+ raw device 0 can not be used due to a bug in certain versions of the
+ "raw" utility (including that shipped with RHEL4U4.)
+
+You may not mix raw and SCSI devices in the test specification.
Running
-------
and where it should keep its working files. Customisation variables are
described clearly at the start of the script.
+e.g.: scsidevs=/dev/sda size=128 crghi=16 thrhi=32 ./sgpdd-survey
+
When the script runs, it creates a number of working files and a pair of
result files. All files start with the prefix given by ${rslt}.
If not all the sgp_dd instances successfully reported a bandwidth number
"failed" is printed.
-
Visualising Results
-------------------
regions) all seem to land on top of each other, it shows the device is
phased by seeks at the given record size.
-
-The included script, parse.pl will process output files and create .csv files fo spreadsheet import
+The included script "plot-sgpdd" will process output files and create
+.dat (similar to csv) files for spreadsheet import. It also plots the
+results directly using gnuplot and creates .png files.