Is it possible to have a cluster Disk from cloud storage

Question

I have a use case where my destination array of my primary storage array I want to keep in the cloud. Using cloud storage controllers i believe it's possible to have data replication on the remote cloud storage.

Now using microsoft clustering i want to create a cluster of two nodes - Node A and Node B. Both these nodes are in my org premises.

With Node A i connect the local storage array and present a SAN disk to it. This SAN disk is imported into the microsoft failover cluster as a cluster disk.
With Node B I want to connect a virtual disk obtained directly from cloud. This cloud disk is the destination disk (due to the data replication between the two disks they will always be trying to sync) of the primary disk which we connected to Node A.

My Question is whether it's possible to have such a virtual disk carved out from cloud storage which can be included as a cluster disk into microsoft failover cluster. And at the backend act as the destination disk of my local storage array disk.

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sk

Answer 1

so I think you have two issues here. The first is you want replication between your local SAN and cloud storage, which I haven't seen any commercially available options so far.

The other is you want to use a disk on top of cloud storage. In Azure you have the option to use Azure Drive which implements an NTFS drive on top of Blob Storage. However this only works from inside Azure, you can't mount a drive from Azure Storage to a local machine.

Another point about your setup is the cluster resource - typically you setup a cluster using a shared resource, read both of your nodes would access the same resource. In your outlined scenario though you're trying to replace the shared resource by a replicated resource, I'm not quite sure if this is a valid setup for the cluster. Otherwise you won't be able to use Azure Drive as Shared resource since both nodes would have R/W while Azure Drive allows only exclusive R/W for one node.

Seems there are some issues with your concept outside of the Azure part which you may need to verify.

Answer 2

Thanks for responding.

You mentioned that it's not possible to mount a drive from Azure Storage to a local machine. Does that mean that cluster storage can't be added as a cluster disk in the failover cluster? If not, just was curious to know if microsoft has any future plan to provide such an option (via PaaS or IaaS) or if any other vendors presently provide such an option.

The whole point is to obtain a virtual disk from cloud which can be added as a resource (cluster disk) in the cluster. 

Regarding your point that it should be resource and not a replicated resource, it's perfectly correct. However there are solutions which don't let the cluster software realize that it's a replicated resource but take it as a shared resource. So this is not a issue.

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sk

Answer 3

Hi - thanks for the question - I'd invite you to read our blog post on Azure Drives, Disks, and Images, which describes our support of disk type scenarios.  If you have any follow-ups, of course, let us know and we'll try to help!

http://blogs.msdn.com/b/windowsazurestorage/archive/2012/06/28/exploring-windows-azure-drives-disks-and-images.aspx

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-Jeff

Answer 4

Jeff ...Thanks for providing the useful link. From the link looks like page blobs can be presented as raw disks which can be mounted and formatted in the host.

- I believe we can assign any drive letter to the disk. Right?

- Can we present this disk as a cluster disk into the failover cluster and create Cluster Shared Volumes on it?

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sk

Answer 5

Jeff ...Thanks for providing the useful link. From the link looks like page blobs can be presented as raw disks which can be mounted and formatted in the host.

- I believe we can assign any drive letter to the disk. Right?

- Can we present this disk as a cluster disk into the failover cluster and create Cluster Shared Volumes on it?

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sk

Jeff ... Could you please share your inputs.

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sk

Answer 6

Hi sk,

We do not support mounting a cloud-based drive from a machine or VM located on premises.

Nor do we support shared cluster volumes.

With both CloudDrives and IaaS disks, you can control which drive letter is assigned to the drive.  (Although I realize that isn't much help for you given the previous two answers).

Let me know if you have any other questions.

Thanks
Andrew Edwards
Windows Azure Storage

Answer 7

Is there any alias/email-id i can send my queries to for more interaction.

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sk

Answer 8

Hi sk,

We do not support mounting a cloud-based drive from a machine or VM located on premises.

Nor do we support shared cluster volumes.

With both CloudDrives and IaaS disks, you can control which drive letter is assigned to the drive.  (Although I realize that isn't much help for you given the previous two answers).

Let me know if you have any other questions.

Thanks
Andrew Edwards
Windows Azure Storage

Regarding the control over driveletter

- Does this mean that a windows application configured to use the data from a local drive (e.g. D:\ ) does not need any implementation change for using the data if same D:\ is provided by IaaS and CloudDrives?

- Can I import this CloudDrive into microsoft cluster framework as a cluster disk?

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sk

Answer 9

Hi sk,

We do not support mounting a cloud-based drive from a machine or VM located on premises.

Nor do we support shared cluster volumes.

With both CloudDrives and IaaS disks, you can control which drive letter is assigned to the drive.  (Although I realize that isn't much help for you given the previous two answers).

Let me know if you have any other questions.

Thanks
Andrew Edwards
Windows Azure Storage

Regarding the control over driveletter

- Does this mean that a windows application configured to use the data from a local drive (e.g. D:\ ) does not need any implementation change for using the data if same D:\ is provided by IaaS and CloudDrives?

- Can I import this CloudDrive into microsoft cluster framework as a cluster disk?

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sk

Need your inputs

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sk

Answer 10

Hi sk,

Yes, a windows application can just use d:\ when that is an IaaS drive or a CloudDrive without any changes, provided that the application is running inside the Azure cloud.

Cluster disks are not supported at this time.

Thanks
Andrew Edwards
Windows Azure Storage