[OpenIndiana-discuss] Buggy mptsas or multipath or something ...

[Lucas Van Tol]

I saw similar issues to that vision multiplier with any firmware > P7 for the 9211-8i cards and an expander;
perhaps you would see better results if you downgraded?  

Also, I think the system gives multi-path device names even if there is only one path; try 
mpathadm list lu 
to see if it is actually doing anything with multiple paths.

-Lucas Van Tol


> Date: Wed, 22 Jun 2011 21:58:47 +1200
> From: mark0x01 at gmail.com
> To: openindiana-discuss at openindiana.org
> Subject: [OpenIndiana-discuss] Buggy mptsas or multipath or something ...
> 
> I have spent more than a week battling my first sas2 storage build.
> 
> It may be a bug somewhere, but I'm not sure what to point a finger at
> but I can reproduce it.
> 
> The goal is about 50Tb of usable storage built mainly with Supermicro 
> kit, with a supported controller. I have build a number of these with 3G 
> sas components and, with the right disks, they work great.
> 
> Apart from the "standard" issues with sata disks and expanders, and 
> working out what to avoid, things have been pretty good on sas 
> generation 1, but things have moved on to generation 2.
> 
> It's been deja vu for an IT fossil like me, as it's like going back to 
> the bad old days of fibre channel, where vendors all built gear to the 
> same standard, but none of it would talk to anyone else's.
> 
> The first encounter was this nice "vision multiplier", 4 devices for the 
> price of one...   http://kb.lsi.com/KnowledgebaseArticle16414.aspx
> 
> Having overcome that hurdle, it was on to the next.
> 
> With any of my 2Tb Sas disks installed, the oi_147 text installer simply 
> exited to a locked up state when enumerating the disks.
> So did Solaris 11 text installer, so it is not just oi.
> 
> Dropping to the shell first and checking out what disks were visible was 
> revealing.
> cfgadm only showed the two for the os.
> format saw all four, well sort of.
> 
> AVAILABLE DISK SELECTIONS:
> 	0. c1t5000C5003434E723d0 <SEAGATE-ST32000444SS-0006 cyl 60798 alt 2 hd 
> 255 sec 252>
> 	/scsi_vhci/disk/@g5000c5003434e723
> 
> Now that's weird, this is multipath.
> 
> But neither of the os disk's are !!
> and they are connected to the same controller and backplane.
> 
> 2. c2t5000C5000A85BA89d0 <IBM-ESXS-ST373455SS-BA2D cyl 72629 alt 2 hd 2 
> sec 897>
> 	/pci at 0,0/pci8086,4027&7/pci8086,3500&0/pci,3510&0/pci1000,3020 at 0/iport&f0/disk at w5000c5000a85ba89,0
> 
> I know that sas2 allows multilane operation between the controller and 
> expanders if the vendor chooses to implement it, so multipath may be 
> needed as it is enabled with the installer mpt_sas.conf, but something 
> isn't quite right here.
> 
> With only the two os disk plugged in, the installation completed 
> normally, as did the reboot.
> I then disabled the multipath option from /kernel/drv/mpt_sas.conf and 
> rebooted and things still worked, so I took a deep breath and plugged in 
> the rest of the disks.
> No crash, and a big bunch of "normal" disks appeared.
> 
> I disabled the multipath as on one of the many "loops" over several 
> days, I had done this and crashed the server when the disks were added
> with multipath left at the installer default of enabled.
> 
> check cfgadm - all listed the same as the OS, and also good in format.
> 
> I should also add I started this install with two controllers intending 
> to use multipath, but having had so much "fun" even getting to this 
> point, it will stay single path until I have a spare month or two to 
> take it further.
> 
> Hardware:
> SM 847E26 chassis, X7DWN+ m/b and 2 x LSI 9211-8i fw P9(patched) in IR 
> mode, 30 x ST32000444SS.
> 
> So when is multipath the wrong path ?
> When the installer takes a $ each way.
> 
> And I don't even have two controllers installed, but there "may" be more 
> than one path, if you are the right device that is.
> 
> I conclude the mptsas driver will probably require more work as vendor 
> uptake on the many new sas2 features available appear.
> 
> Mark.
> 
> 
> 
> 
> 
> 
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