Async verify HOWTO/man update

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index 55662d34bae7d7cc2ed46a6b87d2a5fa971568ee..5099c83c8fd7913773de58285ff323e2bdaec4d0 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -832,7 +832,10 @@ verify_async=int   Fio will normally verify IO inline from the submitting
                thread. This option takes an integer describing how many
                async offload threads to create for IO verification instead,
                causing fio to offload the duty of verifying IO contents
-               to one or more separate threads.
+               to one or more separate threads. If using this offload
+               option, even sync IO engines can benefit from using an
+               iodepth setting higher than 1, as it allows them to have
+               IO in flight while verifies are running.
 
 verify_async_cpus=str  Tell fio to set the given CPU affinity on the
                async IO verification threads. See cpus_allowed for the

diff --git a/fio.1 b/fio.1
index 7b1fc8029008e683b17cb4710ea586285e1c0cd8..fa54763dbc43fca5876f287fac908384d82b3d89 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -602,7 +602,9 @@ false.
 Fio will normally verify IO inline from the submitting thread. This option
 takes an integer describing how many async offload threads to create for IO
 verification instead, causing fio to offload the duty of verifying IO contents
-to one or more separate threads.
+to one or more separate threads.  If using this offload option, even sync IO
+engines can benefit from using an \fBiodepth\fR setting higher than 1, as it
+allows them to have IO in flight while verifies are running.
 .TP
 .BI verify_async_cpus \fR=\fPstr
 Tell fio to set the given CPU affinity on the async IO verification threads.