Comments on: Is PCI RAID clustering finally dead? http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/ Storage Solutions for Real World IT Professionals Mon, 15 Mar 2010 17:55:05 +0000 http://wordpress.org/?v=1.5.2 Comment on Is PCI RAID clustering finally dead? by: paper shredder http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-14554 Sat, 14 Oct 2006 08:56:32 +0000 http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-14554 Of course each host would have it’s own resources and they have not to be dependable at all. Of course each host would have it’s own resources and they have not to be dependable at all.

]]> Comment on Is PCI RAID clustering finally dead? by: Tom http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-313 Mon, 17 Apr 2006 13:31:39 +0000 http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-313 Errol, First, starting with the whitepaper: Thanks for sending the link. It's a good write-up on MPIO and clustering from our friends at LSI. Note that in some examples they show a PCI SAS RAID card, but never in a clustering configuration - only in an MPIO configuration. So I don't think the paper contradicts the basic premise that Microsoft won't be certifying PCI SAS RAID in a clustering environment. Regarding multiple initiators in the same domain: The easiest way to do that is with SAS expanders supporting zoning. The zoning will allow a shared-none model, i.e., each initiator can have sole access to a subset of the drives. No other initiator will be able to access those drives. Of course the trick is figuring out how to configure the zoning. This configuration is done in-band via SMP, but I'm not aware of any native support in Windows (or any other OS) to configure these expanders. PMC-Sierra seems to have a head-start on zoning. You can probably find something on their website regarding how to configure a shared storage domain. TT Errol,

First, starting with the whitepaper: Thanks for sending the link. It’s a good write-up on MPIO and clustering from our friends at LSI. Note that in some examples they show a PCI SAS RAID card, but never in a clustering configuration - only in an MPIO configuration. So I don’t think the paper contradicts the basic premise that Microsoft won’t be certifying PCI SAS RAID in a clustering environment.

Regarding multiple initiators in the same domain: The easiest way to do that is with SAS expanders supporting zoning. The zoning will allow a shared-none model, i.e., each initiator can have sole access to a subset of the drives. No other initiator will be able to access those drives. Of course the trick is figuring out how to configure the zoning. This configuration is done in-band via SMP, but I’m not aware of any native support in Windows (or any other OS) to configure these expanders. PMC-Sierra seems to have a head-start on zoning. You can probably find something on their website regarding how to configure a shared storage domain.

TT

]]> Comment on Is PCI RAID clustering finally dead? by: Errol Neal http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-305 Sat, 15 Apr 2006 23:30:23 +0000 http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-305 I too am implementing and ISCSI head server wit an external SAS JBOD. Since every diagram of an SAS domain shows that is it capable of supporting multiple initators, I've been searching for information on just how that works. Can you please explain the requires to support this environment? I'm not specifically speaking about clustering, but rather the ability to connect multiple initators to the the storage resources within the same domain. Of course each host would have it's own resources. Regarding clustering and SAS, here is some great info right from the horse's mouth as it were: http://download.microsoft.com/download/5/7/7/577a5684-8a83-43ae-9272-ff260a9c20e2/WinHECwhitepaper2003-LSI.doc I too am implementing and ISCSI head server wit an external SAS JBOD. Since every diagram of an SAS domain shows that is it capable of supporting multiple initators, I’ve been searching for information on just how that works. Can you please explain the requires to support this environment? I’m not specifically speaking about clustering, but rather the ability to connect multiple initators to the the storage resources within the same domain. Of course each host would have it’s own resources.

Regarding clustering and SAS, here is some great info right from the horse’s mouth as it were:

http://download.microsoft.com/download/5/7/7/577a5684-8a83-43ae-9272-ff260a9c20e2/WinHECwhitepaper2003-LSI.doc

]]> Comment on Is PCI RAID clustering finally dead? by: Dennis Hadderingh http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-214 Thu, 30 Mar 2006 18:23:26 +0000 http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-214 Tom, Yes that's exactly what I meant. Each controller would 'own' it's own set of disks and in cases of a server failure the standby server or designated failover server would take over the 'orphaned' set of disks. I've made the decision of combining an iSCSI head server with an external SAS JBOD and a coldspare server. This would still keep the price down compared to FC and keep the door open for further growth with SAS. This is very much a wait and see on what kind of SAS products will emerge in the comming year. I would love to see external cabinets with all the RAID logic internally and a connection to the SAS domain announcing itself as a RAID volume / multiple RAID volumes. As I've said in reply to your other article with some imagination there are some very nice setups that will be made possible with the right SAS gear. Regards, Dennis Tom,

Yes that’s exactly what I meant. Each controller would ‘own’ it’s own set of disks and in cases of a server failure the standby server or designated failover server would take over the ‘orphaned’ set of disks.

I’ve made the decision of combining an iSCSI head server with an external SAS JBOD and a coldspare server. This would still keep the price down compared to FC and keep the door open for further growth with SAS.

This is very much a wait and see on what kind of SAS products will emerge in the comming year. I would love to see external cabinets with all the RAID logic internally and a connection to the SAS domain announcing itself as a RAID volume / multiple RAID volumes.

As I’ve said in reply to your other article with some imagination there are some very nice setups that will be made possible with the right SAS gear.

Regards,

Dennis

]]> Comment on Is PCI RAID clustering finally dead? by: Tom http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-150 Fri, 24 Mar 2006 18:38:09 +0000 http://storageadvisors.adaptec.com/2005/10/24/is-pci-raid-clustering-finally-dead/#comment-150 Dennis, Just to be sure we're talking about the same thing, I assume you're talking about two or more Linux machines, each with a 4805 controller, all talking to the same set of disks. I also assume that each drive is physically owned by just one controller, i.e., there aren't multiple RAID cards all trying to share the same array. This is where the question gets a little tricky because in this weblog we try to avoid discussions on product features - especially features that are not yet announced. However one way to build the configuration I described above is to use SAS switches with zoning. I don't think these parts are shipping yet, but I think we should start seeing them in 2006. This would allow each SAS drive to be assigned to just one RAID controller. During failover, some management software magic would occur to move ownership of those drives to another controller. Would that work for you? TT Dennis,

Just to be sure we’re talking about the same thing, I assume you’re talking about two or more Linux machines, each with a 4805 controller, all talking to the same set of disks. I also assume that each drive is physically owned by just one controller, i.e., there aren’t multiple RAID cards all trying to share the same array.

This is where the question gets a little tricky because in this weblog we try to avoid discussions on product features - especially features that are not yet announced.

However one way to build the configuration I described above is to use SAS switches with zoning. I don’t think these parts are shipping yet, but I think we should start seeing them in 2006. This would allow each SAS drive to be assigned to just one RAID controller. During failover, some management software magic would occur to move ownership of those drives to another controller.

Would that work for you?

TT

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