[OpenIndiana-discuss] sas multipath

[Richard Elling]

This is a bug in the mpt_sas driver. I'm not sure of the RTI date, but I believe it was
scheduled to be fixed soon. I've CC'ed Dan McDonald who has been working in this
area. He'll know for sure :-)
 -- richard

On Feb 7, 2013, at 1:20 AM, Randy S <sim.ple at live.nl> wrote:

> 
> Hi,
> 
> Thanks for the link. I also read this page a few weeks ago and went with the iostat -xnzY 5 command. 
> I think it will be difficult to determine if this is an OI issue or a hardware issue.
> I also noticed that the system responds differently depending on which cable you remove. 
> Main responses being either stopping ( or becomming unresponsive) immediately, or stopping when you plug the cable back in.
> 
> don't really know where to look next.
> 
> Rgds,
> 
> Randy
> 
> 
> 
>> From: real-men-dont-click at gmx.net
>> To: openindiana-discuss at openindiana.org
>> Date: Thu, 7 Feb 2013 09:09:48 +0100
>> Subject: Re: [OpenIndiana-discuss] sas multipath
>> 
>> -----Original message-----
>> From:	Randy S <sim.ple at live.nl>
>> Sent:	Wed 06-02-2013 13:03
>> Subject:	[OpenIndiana-discuss] sas multipath
>> To:	openindiana-discuss at openindiana.org; 
>>> 
>>> Hi all,
>>> 
>>> I have a test system running with OIa7, very much ram, 2 LSI SAS 9207-4i4e 
>>> hba's, 1 sm jbod containing seagate 3Tb sas drives. 
>>> 
>>> I have enabled the multipathing with stmsboot and set it to use 
>>> logical-blocksize, since round-robin symmetric-option isn't functioning.
>>> 
>>> During tests I can see that the system sees the two path's  with mpathadm and 
>>> simple dd tests show that all disks are all accessed at almost maximum speed 
>>> with minimum latency according to iostat. 
>>> We started to test with 4 sas disks in 2 striped mirrors. 
>>> 
>>> All good, but shouldn't it be possible to pull one of the sas cables without 
>>> any disruption to the storage, forcing it to use only one path? (this way 
>>> simulating a broken hba).
>>> When we do this, the whole system grinds to a screeching halt, being almost 
>>> unresponsive.
>>> 
>>> What am I doing wrong. Maybe somebody can point in in the right direction to 
>>> troubleshoot.
>>> 
>>> Rgrds,
>>> 
>>> Randy
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 		 	   		  
>>> _______________________________________________
>>> OpenIndiana-discuss mailing list
>>> OpenIndiana-discuss at openindiana.org
>>> http://openindiana.org/mailman/listinfo/openindiana-discuss
>>> 
>> 
>> Hi Randy,
>> 
>> we set up sas multipath here with 151a7 (Supermicro JBOD, LSI SAS Controller). We tested failover as well. It worked, almost: after disconnecting one cable everything continued to work, BUT when reconnecting the cable, the system stopped working until rebooted.
>> 
>> We didn't find the reason for this, so far.
>> 
>> If you are laying with MPXIO you might take a look into vhci_stat:
>> (http://southbrain.com/south/software/vhci-stat.html)
>> 
>> 
>> cu
>> 
>> Carsten
>> 
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>> OpenIndiana-discuss at openindiana.org
>> http://openindiana.org/mailman/listinfo/openindiana-discuss
> 
> 
> 
> 		 	   		  
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--

Richard.Elling at RichardElling.com
+1-760-896-4422