Data ONTAP Discussions

MetroCluster and SAS

I understand that this is pending, but what is this going to look like? Is this going to be a SAS-FC bridge? If so, does this open any options for customers expanding an existing MetroCluster by adding SAS shelves attached via FC? Are there going to be any restrictions on MetroCluster config and Data ONTAP version? Will the support also be open for SSD? Sorry for the question dump! Smiley Happy

I have a number of customers keen to get some new SAS shelves into the MetroCluster config, and a few customers stalling on purchasing a MetroCluster and committing to old DS14 technology.


Re: MetroCluster and SAS

Yes it is going to be a FC-->SAS bridge (1U pizza box) .. you would need two such bridges per stack of shelves  .. it supports 3/6 GB SAS ports and 4/8 GB FC ports .. only Sierra shelves can be in the stack (DS4243/DS2246) .. sierra and DS14 cannot coexist within the same stack but can coexist within the same system ..

Once this bridge is released (plan is summer 2011), existing MC customers with DS14 shelves can expand storage .. however new aggregates will have to be created and new mirrors of those aggregates .. this is because syncmirror between FC-->SAS/SATA disks is disallowed .. there may be a possibility that it will be allowed  in the future since FC and SAS disk behavior is similar

No SSD support planned for the initial release, but we are looking into it

Re: MetroCluster and SAS

What is the minimum Ontap-Version to have MC with SAS bridge and what kind of FAS-Models will be supported?

Is there a official Document?



Re: MetroCluster and SAS



Re: MetroCluster and SAS


now 18 months later are my question:

  • is ssd usage now supportet in stretched metro clusters ?
  • is ssd usage now supportet in switched metro cluster ?
  • can we built now ssd only metro clusters ?
  • what´s about the new feature flash pool in metro clusters ?

I found nothing abaut that in the 8.1.1RC1 release notes or in the field portal.

Does anybody have new informations about that ?

Thanks a lot.


Re: MetroCluster and SAS

The metrocluster compatibility matrix does not show SSD support yet.

I have not seen a public announcement yet, but under NDA you can get probably more information.

Re: MetroCluster and SAS

Hello Pascal,

thanks for your answer.

I thought Metro Cluster Compatibility Guide is very less helpfull for my question, because it list only supported Diskdetails for "old" DS14MKx Shelfs.

Some words to ATTO Bridge/Firmare at Page 12. "Newer" Diskshelves DS4243 and DS2246 also listed at page 12, but without words about:

  • Supported Firmware of IOM3/IOM6
  • Supported Disktypes in newer Shelfs (SAS 15K, SAS 10K, SATA, SSD or what else)
  • Whats abaut newer Shelftypes DS4246 and DS4486

So still questions here.

At initial Release of Ontap 8.0.1 the SSD support cames up, but not for stretched/switched cluster.

"No SSD support planned for the initial release, but we are looking into it"

This is 2 years ago.

Thanks for additional clearness


Re: MetroCluster and SAS

On page 25 of TR-3548 you can read:


DS14 OK and no support for Flash Pools

DS4243 or DS2246, as of Ontap8.1.1 = no support for pure SSD in 8.1.1RC1

                                                       = Support for Flash Pools in Ontap 8.1.1

Hope this answers part of your questions. This TR was updated in June, so it is quite actual.


Re: MetroCluster and SAS

Thanks Peter !

This is exactly what i am looking for.

That means:

no SSD only stretched/switched Cluster

but flash pool (hybrid aggregates) support with 8.1.1


Re: MetroCluster and SAS

Hello Chris.

>Technical FAQ: Flash Pool Jay White, NetApp December 2012

Does Flash Pool work with MetroCluster?

Answer: Yes. Flash Pool is supported with MetroCluster. The following list describes important considerations and requirements that are specific to deploying Flash Pool with MetroCluster:

  • Mixed stack (and shelf) support is the same as for non-MetroCluster systems.
  • Storage stack depth when using SSDs (containing SSD only or mixed SSD + HDD shelves) is 4 disk shelves (as for non-MetroCluster systems).
  • 21 Flash Pool Technical FAQ NetApp Confidential – Limited Use
  • DS14mk4 FC disk shelves and FC disk drives are not supported with Flash Pool in MetroCluster configurations.