DM-Multipather with initialization probem ?

DM-Multipather with initialization probem ?

[Achim Warnecke]

After setup of 40 vdisks, zoning of two switches, etc. and starting I/O I
did a goodpath-test with Redhat 5.1.
Everything worked fine. During running the failover test's the
dm-multipather didn't handle to re-establish
all paths correctly.

I tried running multipathd with "-v4" option for verbose logging. And
changed the
line "daemon $DAEMON" with "daemon $DAEMON -v4" in /etc/init.d/multipathd
file
and restarted the daemon by running "/etc/init.d/multipathd restart" again.

After that the failover worked fine, with and without the -v4 option.
In my setup this behavior is reproducible.
Could there be a connection with specifically starting the multipathd ?

--------before teststart--------
QL_0 (36005076801b080fb7000000000000dac) dm-16 IBM,2145
[size=500M][features=1 queue_if_no_path][hwhandler=0]
\_ round-robin 0 [prio=100][active]
 \_ 5:0:1:0  sdbu 68:128 [active][ready]
 \_ 4:0:0:0  sdci 69:96  [active][ready]
\_ round-robin 0 [prio=20][enabled]
 \_ 5:0:0:0  sdbg 67:160 [active][ready]
 \_ 4:0:1:0  sdcw 70:64  [active][ready]
QL_10 (36005076801b080fb7000000000000db5) dm-26 IBM,2145
[size=2.0G][features=1 queue_if_no_path][hwhandler=0]
\_ round-robin 0 [prio=100][active]
 \_ 5:0:0:10 sdbq 68:64  [active][ready]
 \_ 4:0:1:10 sddg 70:224 [active][ready]
\_ round-robin 0 [prio=20][enabled]
 \_ 5:0:1:10 sdce 69:32  [active][ready]
 \_ 4:0:0:10 sdcs 70:0   [active][ready]
[root@x455-tic-1 ~]#

Kind regards, Achim

Re: DM-Multipather with initialization probem ?

[Chandra Seetharaman]

Hi Achim,

What is the "failback" set to in your configuration file ?

If it is set to "manual" then the failed path will not become active by
themselves. If you want them to be automatic, I would suggest setting it
to "immediate".

More details can be found at
http://sources.redhat.com/lvm2/wiki/MultipathUsageGuide

regards,

chandra
On Mon, 2008-01-28 at 15:53 +0100, Achim Warnecke wrote:
> 
> After setup of 40 vdisks, zoning of two switches, etc. and starting I/O I
> did a goodpath-test with Redhat 5.1.
> Everything worked fine. During running the failover test's the
> dm-multipather didn't handle to re-establish
> all paths correctly.
> 
> I tried running multipathd with "-v4" option for verbose logging. And
> changed the
> line "daemon $DAEMON" with "daemon $DAEMON -v4" in /etc/init.d/multipathd
> file
> and restarted the daemon by running "/etc/init.d/multipathd restart" again.
> 
> After that the failover worked fine, with and without the -v4 option.
> In my setup this behavior is reproducible.
> Could there be a connection with specifically starting the multipathd ?
> 
> --------before teststart--------
> QL_0 (36005076801b080fb7000000000000dac) dm-16 IBM,2145
> [size=500M][features=1 queue_if_no_path][hwhandler=0]
> \_ round-robin 0 [prio=100][active]
>  \_ 5:0:1:0  sdbu 68:128 [active][ready]
>  \_ 4:0:0:0  sdci 69:96  [active][ready]
> \_ round-robin 0 [prio=20][enabled]
>  \_ 5:0:0:0  sdbg 67:160 [active][ready]
>  \_ 4:0:1:0  sdcw 70:64  [active][ready]
> QL_10 (36005076801b080fb7000000000000db5) dm-26 IBM,2145
> [size=2.0G][features=1 queue_if_no_path][hwhandler=0]
> \_ round-robin 0 [prio=100][active]
>  \_ 5:0:0:10 sdbq 68:64  [active][ready]
>  \_ 4:0:1:10 sddg 70:224 [active][ready]
> \_ round-robin 0 [prio=20][enabled]
>  \_ 5:0:1:10 sdce 69:32  [active][ready]
>  \_ 4:0:0:10 sdcs 70:0   [active][ready]
> [root@x455-tic-1 ~]#
> 
> Kind regards, Achim
> 
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> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
-- 

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