[dm-devel] Multipath-tools errors

Chandra Seetharaman sekharan at us.ibm.com
Thu Aug 16 19:05:40 UTC 2007 

On Thu, 2007-08-16 at 20:36 +0200, S. J. van Harmelen wrote:
> In my last lines I meant that it looked okay:
> 
> root at storage:~# multipath -ll
> backup (360019b9000d7e1100000444b46be82c4) dm-0 DELL    ,MD3000        
> [size=200G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=3][active]
>  \_ 1:0:1:2 sdg 8:96  [active][ready]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 1:0:0:2 sdd 8:48  [active][ghost]
> vmware (360019b9000d7e1100000444846be81b6) dm-2 DELL    ,MD3000        
> [size=200G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=3][active]
>  \_ 1:0:0:0 sdb 8:16  [active][ready]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 1:0:1:0 sde 8:64  [active][ghost]
> data (360019b9000d7ddab0000493846be81e5) dm-1 DELL    ,MD3000        
> [size=200G][features=0][hwhandler=0]
> \_ round-robin 0 [prio=3][active]
>  \_ 1:0:1:1 sdf 8:80  [active][ready]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 1:0:0:1 sdc 8:32  [active][ghost]
> 
> As you can see it show's all paths correctly and also show's them as

Yes, they all look good.

> active/ready and active/ghost. Attached is my multipath.conf b.t.w.
> 
Your multipath.conf looks good too.

> But I understand path failover/failback will not work without without
> the hardware handler :( I am planning this machine for a production

Your storage is configured in AVT mode or rdac mode ?

You wont need the handler if your storage is configured in AVT mode.
 
> environment, so I quess I have to wait till 2.6.23.1 comes out.

If you are using it in rdac mode, then you have to wait.

> 
> Any idea when that should be? Or are there any kernel patches I could

Usually they are released within 2-3 months of the last release. 2.6.22
was released on Jul 8th. So, it should be somewhere between Sep 8th and
Oct 8th :)...

> use for 2.6.22.2? Or does it not work that way?

It would work, but I would not suggest it :), especially for a
production system.

chandra
> 
> Thanks,
> 
> Sander
> 
> 
> 
> 
> On Thu, 2007-08-16 at 11:23 -0700, Chandra Seetharaman wrote:
> > On Thu, 2007-08-16 at 19:58 +0200, S. J. van Harmelen wrote:
> > > Hi Chandra,
> > > 
> > > Thanks for your reply! As far as I know it does use a LSI Engenio. I
> > > asked Dell if they can confirm this, but I didn't get any reply yet.
> > > Will get back with the answer as soon as I get it.
> > > 
> > My reply below is based on the assumption that it does use LSI Engenio.
> > 
> > > Besides that it seems to be working now. I don't have any errors anymore
> > > and it's not as slow as before. It's now doing something like 120M/sec,
> > > but don't know if thats good or not (don't know how fast this device
> > > should be)...
> > > 
> > > I did leave out the hardware_handler line because of the error it gives.
> > > But I understand that is because of my kernel? I'm using the package
> > > from Christophe's website version 0.4.8 on a Debian Etch 64bit machine
> > > with a 2.6.22.2 kernel.
> > 
> > Yes, you need a 2.6.23-rc1 (or upwards) kernel to have the rdac hardware
> > handler support.
> > > 
> > > I quess I need the hardware_handler to make it work as it should? Al
> > 
> > Yes, without the hardware handler, path failover/failback will not work.
> > 
> > > true it sees all paths and says that both active. Where one is
> > > active/ready and the other is active/ghost. 
> > > 
> > > Anything I can do about this? 
> > 
> > I do not understand the problem you are mentioning here. Will be easier
> > to follow if you can copy the o/p of "multipath -ll" and explain your
> > issue w.r.t that.
> > 
> > Also, attaching your multipath.conf would also be useful.
> > 
> > chandra
> > > 
> > > Sander
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > On Thu, 2007-08-16 at 10:26 -0700, Chandra Seetharaman wrote:
> > > > First off, the "mpath_prio_rdac" is the path checker for the lsi engenio
> > > > controller. Is the Dell MD300 based on that controller ?
> > > > 
> > > > If it is _not_, then you should _not_ be using mpath_prio_rdac.
> > > > 
> > > > If it is, read on.
> > > > 
> > > > You need to use the hardware handler for the same controller, you can
> > > > setup your multipath.conf to use the "rdac" hardware handler.
> > > > 
> > > > Here is how your multipath.conf should look like:
> > > > -----------
> > > > devices {
> > > >         device {
> > > >                 vendor                  "$vendor_name"
> > > >                 product                 "$product_name"
> > > >                 hardware_handler        "1 rdac"
> > > >                 path_checker            rdac
> > > >                 path_grouping_policy    group_by_prio
> > > >                 prio_callout            "/sbin/mpath_prio_rdac /dev/%n"
> > > >         }
> > > > }
> > > > -----------
> > > > 
> > > > Note: replace $vendor_name and $product_name with appropriate vendor and
> > > > product information for the storage.
> > > > 
> > > > Hardware handler for rdac is available only in 2.6.23-rc1 and onwards
> > > > (if you are not using this version, do let me know which version of the
> > > > kernel you are using, even if it is in distro).
> > > > 
> > > > Where did you get the multipath-tools from ? From Christophe's website
> > > > or any distro(RedHat/SuSE) ?
> > > > 
> > > > And, as Malahal pointed, make sure you have /sbin/mpath_prio_rdac
> > > > available and is an executable.
> > > > 
> > > > Hope this helps,
> > > > 
> > > > chandra
> > > > On Fri, 2007-08-10 at 16:50 +0200, S. J. van Harmelen wrote:
> > > > > Oke, got a bit further...
> > > > > 
> > > > > I now understand how to use the disks. Only thing thats not going oke is
> > > > > that I get these errors constantly (while formatting):
> > > > > 
> > > > > end_request: I/O error, dev sdf, sector 30408704
> > > > > end_request: I/O error, dev sdf, sector 30670848
> > > > > end_request: I/O error, dev sdf, sector 30932992
> > > > > end_request: I/O error, dev sdf, sector 31195136
> > > > > end_request: I/O error, dev sdf, sector 31457280
> > > > > 
> > > > > or (while editting a file):
> > > > > 
> > > > > end_request: I/O error, dev sdc, sector 966656
> > > > > device-mapper: multipath: Failing path 8:32.
> > > > > end_request: I/O error, dev sdc, sector 966720
> > > > > device-mapper: multipath: Failing path 8:32.
> > > > > end_request: I/O error, dev sdc, sector 96665
> > > > > 
> > > > > And the device seems very slow...
> > > > > 
> > > > > And also stil having this error: "error calling out mpath_prio_rdac"
> > > > > 
> > > > > Any tips, pointers?
> > > > > 
> > > > > Sander
> > > > > 
> > > > > -------- Forwarded Message --------
> > > > > From: S. J. van Harmelen <svanharmelen at xillan.nl>
> > > > > To: dm-devel at redhat.com
> > > > > Subject: Re: Multipath-tools
> > > > > Date: Fri, 10 Aug 2007 11:47:01 +0200
> > > > > 
> > > > > Hi again,
> > > > > 
> > > > > Seem to have found the solution for the first question. Got
> > > > > multipath-tools up and running now :)
> > > > > 
> > > > > But please do answer the others questions if you have a minute to
> > > > > spare...
> > > > > 
> > > > > Also I'm seeing "error calling out mpath_prio_rdac" when starting
> > > > > multipathd?! Any word on that one?
> > > > > 
> > > > > Regards,
> > > > > 
> > > > > Sander
> > > > > 
> > > > > 
> > > > > 
> > > > > On Fri, 2007-08-10 at 10:27 +0200, S. J. van Harmelen wrote:
> > > > > > Hey guys,
> > > > > > 
> > > > > > Sorry to bother you, but I have a question I think you can answer. I
> > > > > > also send this message to Christophe, but I don't know how long he takes
> > > > > > to respond. I'm trying to set up a Dell NX1950 which has an RDAC MD300
> > > > > > array connected with linux.
> > > > > > 
> > > > > > Now I got all thinks working, but the RDAC driver. I'm trying to use the
> > > > > > opensource multipath-tools (which I want to compile myself), but I have
> > > > > > some questions about it:
> > > > > > 
> > > > > > 1) While compiling I get an error saying: "/usr/bin/ld: cannot find
> > > > > > -ldevmapper" Can you tell me what I can do to fix this error?
> > > > > > 
> > > > > > 2) Can you tell me if there is a mailinglist for the multipath-tools?
> > > > > > 
> > > > > > 3) Can you point me to some documentation about configuring the
> > > > > > multipath-tools with the new RDAC path checker?
> > > > > > 
> > > > > > Thanks very much for your time!
> > > > > > 
> > > > > > Kind regards,
> > > > > > 
> > > > > > Sander van Harmelen
> > > > > 
> > > > > --
> > > > > dm-devel mailing list
> > > > > dm-devel at redhat.com
> > > > > https://www.redhat.com/mailman/listinfo/dm-devel
> > > > -- 
> > > > 
> > > > ----------------------------------------------------------------------
> > > >     Chandra Seetharaman               | Be careful what you choose....
> > > >               - sekharan at us.ibm.com   |      .......you may get it.
> > > > ----------------------------------------------------------------------
> > > > 
> > > > 
> > > > --
> > > > dm-devel mailing list
> > > > dm-devel at redhat.com
> > > > https://www.redhat.com/mailman/listinfo/dm-devel
> > > 
-- 

----------------------------------------------------------------------
    Chandra Seetharaman               | Be careful what you choose....
              - sekharan at us.ibm.com   |      .......you may get it.
----------------------------------------------------------------------

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