Adds verify_only option
When this option is set, a dry run (no actual io is performed) of the
workload will be done in order to compute the numberio for each block
header without overwriting the data on disk. Then, do_verify() will be
effectively verifying data that was written in a previous fio run.
In the case that "loops" is set to more than 1, do_verify() will delay
the verification of numberio to the last iteration when the same
numberio state that would have been written to disk in a previous
fio run has been reached.
Signed-off-by: Juan Casse <jcasse@chromium.org>
Reviewed-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/HOWTO b/HOWTO
index e69cf41..9830fa1 100644
--- a/HOWTO
+++ b/HOWTO
@@ -1068,6 +1068,13 @@
to repeat the same workload a given number of times. Defaults
to 1.
+verify_only Do not perform specified workload---only verify data still
+ matches previous invocation of this workload. This option
+ allows one to check data multiple times at a later date
+ without overwriting it. This option makes sense only for
+ workloads that write data, and does not support workloads
+ with the time_based option set.
+
do_verify=bool Run the verify phase after a write phase. Only makes sense if
verify is set. Defaults to 1.
@@ -1106,7 +1113,9 @@
meta Write extra information about each io
(timestamp, block number etc.). The block
- number is verified. See also verify_pattern.
+ number is verified. The io sequence number is
+ verified for workloads that write data.
+ See also verify_pattern.
null Only pretend to verify. Useful for testing
internals with ioengine=null, not for much