[dm-devel] [PATCH] multipathd: update defaults

[Hannes Reinecke]

For years I've been telling our customers to use the 'tur' checker
as the current default 'directio' will cause spurious path failures
under high load.

And for several versions (years, even) the linux kernel has the ability
to correctly detect the device handler, so we should be making
'retain_hw_handler' the default.
And if we do this we also want to enable 'detect_prio', to ensure
we pick the correct prioritizer.

So this patch updates the default setting to always enable
'retain_hw_handler' and 'detect_prio' and switch to 'tur'
as the default path checker.

Signed-off-by: Hannes Reinecke <hare at suse.de>
---
 libmultipath/checkers.h    | 2 +-
 libmultipath/defaults.h    | 4 ++--
 multipath/multipath.conf.5 | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libmultipath/checkers.h b/libmultipath/checkers.h
index a935b3f..374c826 100644
--- a/libmultipath/checkers.h
+++ b/libmultipath/checkers.h
@@ -85,7 +85,7 @@ enum path_check_state {
 #define READSECTOR0  "readsector0"
 #define CCISS_TUR    "cciss_tur"
 
-#define DEFAULT_CHECKER DIRECTIO
+#define DEFAULT_CHECKER TUR
 
 #define ASYNC_TIMEOUT_SEC	30
 
diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
index 96f5a2c..4948271 100644
--- a/libmultipath/defaults.h
+++ b/libmultipath/defaults.h
@@ -16,8 +16,8 @@
 #define DEFAULT_FIND_MULTIPATHS	0
 #define DEFAULT_FAST_IO_FAIL	5
 #define DEFAULT_DEV_LOSS_TMO   600
-#define DEFAULT_RETAIN_HWHANDLER RETAIN_HWHANDLER_OFF
-#define DEFAULT_DETECT_PRIO DETECT_PRIO_OFF
+#define DEFAULT_RETAIN_HWHANDLER RETAIN_HWHANDLER_ON
+#define DEFAULT_DETECT_PRIO DETECT_PRIO_ON
 #define DEFAULT_DEFERRED_REMOVE DEFERRED_REMOVE_OFF
 #define DEFAULT_DELAY_CHECKS DELAY_CHECKS_OFF
 #define DEFAULT_UEVENT_STACKSIZE 256
diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
index aaaa01b..20a2304 100644
--- a/multipath/multipath.conf.5
+++ b/multipath/multipath.conf.5
@@ -295,7 +295,7 @@ Check the path state for LSI/Engenio/NetApp E-Series RDAC storage controller.
 .B directio
 Read the first sector with direct I/O.
 .TP
-Default value is \fIdirectio\fR.
+Default value is \fItur\fR.
 .RE
 .TP
 .B failback
@@ -463,7 +463,7 @@ are supported, or the
 prioritizer if not. If set to
 .I no
 , the prioritizer will be selected as usual. Default is
-.I no
+.I yes
 .TP
 .B force_sync
 If set to
-- 
2.6.6