Update HOWTO as well for verify_backlog

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 452e288b0279b76f7fd82997554973b58a3b5284..7cb24dd8c12e764a7ff5c5c5c813efc775418311 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -935,13 +935,18 @@ verify_backlog=int        Fio will normally verify the written contents of a
                associated with an IO block in memory, so for large
                verify workloads, quite a bit of memory would be used up
                holding this meta data. If this option is enabled, fio
+               will write only N blocks before verifying these blocks.
+
                will verify the previously written blocks before continuing
                to write new ones.
 
 verify_backlog_batch=int       Control how many blocks fio will verify
                if verify_backlog is set. If not set, will default to
                the value of verify_backlog (meaning the entire queue
-               is read back and verified).
+               is read back and verified).  If verify_backlog_batch is
+               less than verify_backlog then not all blocks will be verified,
+               if verify_backlog_batch is larger than verify_backlog, some
+               blocks will be verified more than once.
                
 stonewall      Wait for preceeding jobs in the job file to exit, before
                starting this one. Can be used to insert serialization
@@ -988,11 +993,12 @@ read_iolog=str    Open an iolog with the specified file name and replay the
                file first (blkparse <device> -o /dev/null -d file_for_fio.bin).
                
 replay_no_stall=int When replaying I/O with read_iolog the default behavior
-               is to attempt to respect the time stamps within the log and replay
-        them with the appropriate delay between IOPS.  By setting this variable
-        fio will not respect the timestamps and attempt to replay them as fast
-        as possible while still respecting ordering.  The result is the same
-        I/O pattern to a given device, but different timings.
+               is to attempt to respect the time stamps within the log and
+               replay them with the appropriate delay between IOPS.  By
+               setting this variable fio will not respect the timestamps and
+               attempt to replay them as fast as possible while still
+               respecting ordering.  The result is the same I/O pattern to a
+               given device, but different timings.
 
 replay_redirect=str While replaying I/O patterns using read_iolog the
                default behavior is to replay the IOPS onto the major/minor
@@ -1255,8 +1261,10 @@ For scripted usage where you typically want to generate tables or graphs
 of the results, fio can output the results in a semicolon separated format.
 The format is one long line of values, such as:
 
-2; client1;0;0;1906777;1090804;1790;0;0;0.000000;0.000000;0;0;0.000000;0.000000;929380;1152890;25.510151%;1078276.333333;128948.113404;0;0;0;0;0;0.000000;0.000000;0;0;0.000000;0.000000;0;0;0.000000%;0.000000;0.000000;100.000000%;0.000000%;324;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%;0.0%;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%
-;0.0%;0.0%;0.0%;0.0%;0.0%
+2;card0;0;0;7139336;121836;60004;1;10109;27.932460;116.933948;220;126861;3495.446807;1085.368601;226;126864;3523.635629;1089.012448;24063;99944;50.275485%;59818.274627;5540.657370;7155060;122104;60004;1;8338;29.086342;117.839068;388;128077;5032.488518;1234.785715;391;128085;5061.839412;1236.909129;23436;100928;50.287926%;59964.832030;5644.844189;14.595833%;19.394167%;123706;0;7313;0.1%;0.1%;0.1%;0.1%;0.1%;0.1%;100.0%;0.00%;0.00%;0.00%;0.00%;0.00%;0.00%;0.01%;0.02%;0.05%;0.16%;6.04%;40.40%;52.68%;0.64%;0.01%;0.00%;0.01%;0.00%;0.00%;0.00%;0.00%;0.00%
+A description of this job goes here.
+
+The job description (if provided) follows on a second line.
 
 To enable terse output, use the --minimal command line option. The first
 value is the version of the terse output format. If the output has to
@@ -1280,6 +1288,8 @@ Split up, the format is as follows:
                Bw: min, max, aggregate percentage of total, mean, deviation
        CPU usage: user, system, context switches, major faults, minor faults
        IO depths: <=1, 2, 4, 8, 16, 32, >=64
-       IO latencies: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, >=2000
-       Text description
-
+       IO latencies microseconds: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
+       IO latencies milliseconds: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000
+       Additional Info (dependant on continue_on_error, default off): total # errors, first error code 
+       
+       Additional Info (dependant on description being set): Text description