Update verify_backlog documentation
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fio.1 b/fio.1
index 9ca38ab..f01bf3a 100644
--- a/fio.1
+++ b/fio.1
@@ -698,13 +698,16 @@
everything is read back and verified. You may want to verify continually
instead for a variety of reasons. Fio stores the meta data 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 verify
-the previously written blocks before continuing to write new ones.
+be used up holding this meta data. If this option is enabled, fio will write
+only N blocks before verifying these blocks.
.TP
.BI verify_backlog_batch \fR=\fPint
Control how many blocks fio will verify if verify_backlog is set. If not set,
will default to the value of \fBverify_backlog\fR (meaning the entire queue is
-read back and verified).
+read back and verified). If \fBverify_backlog_batch\fR is less than
+\fBverify_backlog\fR then not all blocks will be verified, if
+\fBverify_backlog_batch\fR is larger than \fBverify_backlog\fR, some blocks
+will be verified more than once.
.TP
.B stonewall
Wait for preceeding jobs in the job file to exit before starting this one.