[dm-devel] Re: Question regarding failback option in multipath.conf

[Eli Klein]

Sorry, left off a few key details:

I'm running the following:

redhat 5.3 x86_64
device-mapper-1.02.28-2.el5
device-mapper-multipath-0.4.7-23.el5_3.4

Let me know if there are other details that would be helpful.

-Eli

On Sep 30, 2009, at 10:41 AM, Eli Klein wrote:

> I'm running into an issue where the failback option in  
> multipath.conf is being ignored.  I've tried to set this to a value  
> > 0 to cause dm to pause before reinstating a recovered path, but it  
> reinstates the path immediately.  The same is true when setting the  
> value to "manual", the path is reinstated immediately.  The delay is  
> most useful when a ethernet switch has failed or rebooted.  During  
> the boot of the switch, the interface comes up and drops again  
> multiple times.  I'd love to be able to introduce a delay before DM  
> marks the path as reinstated after a recovery.  This would save me  
> the hassle of running into I/O errors (and occasional filesystem RO)  
> as the path bounces while the switch is booting.
>
> Thanks in advance for any help or suggestions!
>
> -Eli
>
> I've included my multipath.conf as well as output from multipath -ll  
> below:
>
> multipath.conf:
>
> blacklist {
>         devnode "sda$"
> #        devnode "*"
> }
>
> ## By default, devices with vendor = "IBM" and product = "S/390.*" are
> ## blacklisted. To enable mulitpathing on these devies, uncomment the
> ## following lines.
> #blacklist_exceptions {
> #	device {
> #		vendor	"IBM"
> #		product	"S/390.*"
> #	}
> #}
>
> ## Use user friendly names, instead of using WWIDs as names.
> defaults {
> 	user_friendly_names yes
> }
> ##
> ## Here is an example of how to configure some standard options.
> ##
> #
> defaults {
> 	udev_dir		/dev
> 	polling_interval 	10
> 	selector		"round-robin 0"
> 	path_grouping_policy	multibus
> 	getuid_callout		"/sbin/scsi_id -g -u -s /block/%n"
> 	prio_callout		/bin/true
> 	path_checker		readsector0
> 	rr_min_io		10
> 	rr_weight		priorities
> 	failback		120
> 	features		"1 queue_if_no_path"
> 	no_path_retry		1
> 	user_friendly_name	yes
> }
>
> multipath -ll:
>
> mpath2 (36000eb3945b8703a00000000000000f4) dm-3 LEFTHAND,iSCSIDisk
> [size=400G][features=1 queue_if_no_path][hwhandler=0][rw]
> \_ round-robin 0 [prio=0][active]
>  \_ 192:0:0:0 sdl 8:176 [active][ready]
>  \_ 191:0:0:0 sdf 8:80  [active][ready]
> mpath152 (36000eb3945b8703a0000000000001431) dm-2 LEFTHAND,iSCSIDisk
> [size=300G][features=1 queue_if_no_path][hwhandler=0][rw]
> \_ round-robin 0 [prio=0][active]
>  \_ 186:0:0:0 sdh 8:112 [active][ready]
>  \_ 185:0:0:0 sde 8:64  [active][ready]
> mpath149 (36000eb3945b8703a0000000000001429) dm-5 LEFTHAND,iSCSIDisk
> [size=300G][features=1 queue_if_no_path][hwhandler=0][rw]
> \_ round-robin 0 [prio=0][active]
>  \_ 189:0:0:0 sdc 8:32  [active][ready]
>  \_ 190:0:0:0 sdi 8:128 [active][ready]
> mpath151 (36000eb3945b8703a000000000000142d) dm-6 LEFTHAND,iSCSIDisk
> [size=300G][features=1 queue_if_no_path][hwhandler=0][rw]
> \_ round-robin 0 [prio=0][active]
>  \_ 188:0:0:0 sdj 8:144 [active][ready]
>  \_ 187:0:0:0 sdg 8:96  [active][ready]
> mpath150 (36000eb3945b8703a0000000000001435) dm-4 LEFTHAND,iSCSIDisk
> [size=200G][features=1 queue_if_no_path][hwhandler=0][rw]
> \_ round-robin 0 [prio=0][active]
>  \_ 184:0:0:0 sdk 8:160 [active][ready]
>  \_ 183:0:0:0 sdd 8:48  [active][ready]

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/dm-devel/attachments/20090930/467a0144/attachment.htm>