[OpenIndiana-discuss] sas multipath

[Randy S]

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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