***SPAM*** Re: [ofa-general] link width problem of Qlogic 9024 unmanaged switch

[Yicheng Jia]

Hi Ira,

>Yea that is going to be a problem.  The problem is that effectively you 
just
> disabled the connection to the switch.  A reset disables then enables 
the
> port.  Once the port is disabled the command can't talk to the switch 
any
> longer.  You will have to either reset the switch (power cycle) or go to
> another node and enable the port.  From the output you sent me it looks 
like
> you don't have any other nodes on the switch, so I take it you are 
resetting
> the switch to get the link to come back?

Thanks your explanation now everything is clear. Can I do "reset" by 
down/enable instead of down/disable/enable so that I can reset the peer 
port on the switch?

> I thought there was a warning in the man page or in the help regarding 
this
> situation but I don't see it now.

There's a warning if I try to reset a port which is not on the switch.

> BTW, What are you trying to achieve with this command?

Sometime there's 1x link on the subnet after reboot our system, which 
consists of several HCA nodes directly connected with the switch. By 
reboot, I mean restart each node. I am trying to achieve 4x link width by 
using this command on 1x link port. Do you have any better idea of 
resolving this problem?

Thanks!
Yicheng Jia





Ira Weiny <weiny2 at llnl.gov> 
04/17/2009 12:45 PM

To
Yicheng Jia <YJia at tmriusa.com>
cc
general at lists.openfabrics.org, Hal Rosenstock <hal.rosenstock at gmail.com>
Subject
Re: ***SPAM*** Re: [ofa-general] link width problem of Qlogic 9024 
unmanaged switch






On Fri, 17 Apr 2009 12:06:43 -0500
Yicheng Jia <YJia at tmriusa.com> wrote:

> Hi Ira,
> 
> Here is the output of "iblinkinfo.pl -R":
> 
> ++++++++++++++++++++++++++++++++++++++++++++++++
> [root at ib_manager ~]# iblinkinfo.pl -R
> Switch 0x00066a00d90009c1 InfiniCon System InfinIO 9024 Lite:
>       7    1[  ]  ==( 4X 2.5 Gbps Active /   LinkUp)==>       6    1[  ] 
"MT2520 4 InfiniHostLx Mellanox Technologies" (  )
>            2[  ]  ==( 4X 2.5 Gbps   Down /  Polling)==>             [  ] 
"" (  )
>            3[  ]  ==( 4X 2.5 Gbps   Down /  Polling)==>             [  ] 
"" (  )
>            4[  ]  ==( 4X 2.5 Gbps   Down /  Polling)==>             [  ] 
"" (  )

[snip]

> 
> And the "ibstat" output:
> +++++++++++++++++++++++++++++++++++
> [root at ib_manager ~]# ibstat
> CA 'mthca0'
>         CA type: MT25204
>         Number of ports: 1
>         Firmware version: 1.2.0
>         Hardware version: a0
>         Node GUID: 0x0002c90200230784
>         System image GUID: 0x0002c90200230787
>         Port 1:
>                 State: Active
>                 Physical state: LinkUp
>                 Rate: 10
>                 Base lid: 6
>                 LMC: 0
>                 SM lid: 6
>                 Capability mask: 0x02500a6a
>                 Port GUID: 0x0002c90200230785
> ++++++++++++++++++++++++++++++++++++++++++++++
> 
> The reset command I am using is "ibportstate 7 1 reset", I also tried 
> "ibportstate -D 0,1 1 reset", and it fails with the same result.
>

Yea that is going to be a problem.  The problem is that effectively you 
just
disabled the connection to the switch.  A reset disables then enables the
port.  Once the port is disabled the command can't talk to the switch any
longer.  You will have to either reset the switch (power cycle) or go to
another node and enable the port.  From the output you sent me it looks 
like
you don't have any other nodes on the switch, so I take it you are 
resetting
the switch to get the link to come back?

I thought there was a warning in the man page or in the help regarding 
this
situation but I don't see it now.

Also, this becomes worse if you disable the port the SM is on.  (Which I 
see
you are doing.)  So you will have a noticeable delay while the SM rescans 
the
network which it is now seeing "again" for the first time.

BTW, What are you trying to achieve with this command?

Hope this helps,
Ira


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