+WARNING: Running sgp_dd will ERASE the contents of the disk devices.
+ This is NOT to be run on any OST where you care about any data
+ or you are not expecting to reformat the filesystem afterward.
Requirements
------------
. sg3_utils (for sgp_dd)
-. SCSI device
+ SCSI device
+ Or, if using non-scsi disk
+ raw device support
+ sg3_utils
Overview
writing a separate area of the disk to show how performance varies with the
number of concurrent stripe files.
+The device(s) used must meet one of two tests:
+SCSI device:
+ Must appear in the output of 'sg_map'
+Raw device:
+ Must appear in the output of 'raw -qa'
+You may not mix raw and SCSI devices in the test specification.
+
Running
-------
total_size 8388608K rsz 1024 thr 1 crg 1 180.45 MB/s 1 x 180.50 = 180.50 MB/s
-The first number is the bandwidth computed by measuring total data and
-elapsed time. The other numbers are a check on the bandwidths reported by
-the individual sgp_dd instances.
+The number immediately before the first MB/s is the bandwidth computed by
+measuring total data and elapsed time. The other numbers are a check on
+the bandwidths reported by the individual sgp_dd instances.
If there are so many threads that sgp_dd is unlikely to be able to allocate
I/O buffers, "ENOMEM" is printed.