Tag: Managed Disks

Azure Preview – Standard SSD Disks

Say what?!?! Standard SSD disks? And we thought that Standard = HDD and Premium = SSD! But that’s no longer the case.

In the coming world of Azure (we’re not there yet), Premium will be just that, but Standard will be normal deployments of either HDD or SSD. How do the three tiers of managed disks break down?

  • Premium: For when you need the highest IOPS, throughput and lowest latency.
  • Standard SSD: For production workloads when you need predictable IOPS performance (500 per disk) with lower latency than HDD.
  • Standard HDD: Test and archive storage in VMs, with IOPS listed as up to 500 IOPS – spinning disks are based on serial access and bursts of activity lead to access queues and lower performance levels.

Let’s set expectations: Standard SSD is in very limited preview today. Only North Europe (Dublin) is supported today, with several more regions coming online internationally by mid-June:

  • France Central
  • East US 2
  • Central US
  • Canada Central
  • East Asia
  • Korea South
  • Australia East

There is no Azure Portal support today. If you want to deploy Standard SSD disks, you must do it using ARM templates:

  • apiVersion for Microsoft.Compute/virtualMachines must be set as “2018-04-01” (or later)
  • storageAccountType as “StandardSSD_LRS”

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Won’t SSD be too expensive compared to HDD? That was my first thought. But check out the RRP pricing (North Europe in Euros). The per-GB pricing for Standard HDD is:

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But the per-GB pricing for Standard SSD disks is:

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The per-GB cost of Standard SSD is LOWER than that of Standard HDD. How could that be? Electricity is a huge cost in data centers, and disk arrays eat up a lot of power. SSD is way more efficient, the cost of SSD has been falling, and Microsoft eats the commodity storage hardware dog food.

If you read the pricing small print, you will notice that the micro-cost of storage transactions in Standard SSD is €0.000844 per 10,000 transactions, double the Standard HDD cost of €0.000422 per 10,000 transactions but that’s one of those costs that’s tucked away at the bottom of the bill that few ever notice because it’s tiny.

Standard SSD, managed disks only, is LRS only, as with other managed disks. They also come with the usual 99.999% availability, and Microsoft’s claimed ZERO percent annualized failure rate.

I’m looking forward to the day that Standard SSD is GA and I can start telling customers to switch over to it as their normal disk, when Premium isn’t required.

Restore An Azure VM to an Availability Set From Azure Backup in the Azure Portal

Microsoft has shared how to restore an Azure VM to an availability set using PowerShell from Azure Backup. It’s nasty-hard looking PowerShell, and my problem with examples of VM creation using PowerShell is that they’re never feature complete.

While writing some Azure VM training recently, I stumbled across a cool option in the Azure Portal that I tried out … and it worked … and it means that I never have to figure that nasty PowerShell out Smile

The key to all this is to start using Managed Disks. Even if your existing VMs are using un-managed (storage account) disks, that’s not a problem because you can still use this restore method. The other thing you should remember is that the metadata of the VM is irrelevant – everything of value is in the disks.

Restore the Disks of the VM

Using these steps you can restore the disks of your VM, managed or un-managed, to a storage location, referred to as the staging account.. Each disk is restored as a blob VHD file, and a JSON file describes the disks so that you can identify which one is the “osDisk”.

Create Managed Disks from the Restored VHDs

In this process, you create a managed disk from each restored VHD or blob file in the staging location. You have the option to restore the disks as Standard (HDD) or Premium (SSD) disks, which offers you some flexibility in your restore (you can switch storage types!). Make sure you ID the osDisk from the JSON file and mark it as either a Windows or Linux OS disk, depending on the contents.

Create a VM From the OS Managed Disk

The third set of steps bring your VM back online. You use the previously restored/identified osDisk and create a new virtual machine using that managed disk. Make sure you select the availability set that you want to restore the VM to.

Clean Up

The last step is the clean up. If you had any data disks in the original machine then you need to re-attach them to the new virtual machine. You’ll also need to configure the network settings of the Azure NIC resource. For example, if the new VM is replacing the old one, you should enter the IP settings of the old VM into the new NIC Azure resource, change any NAT/load balancing rules, NSGs, PIPs, etc.

And that’s it! There’s no PowerShell, and it’s all pretty simple clicking in the Azure Portal that won’t take that long to do after the disks are restored from the recovery services vault.

Create a New VM From An Existing Managed Disk

In previous posts I have shown how to restore the disks of a VM to a storage account and how to create managed disks from those VHD blobs. In this post, I will show how to create a new VM from a managed disk. When these 3 steps are done together, this is an easy way to restore an Azure virtual machine from backup to an availability set.

I previously created a managed disk from a restored VHD blob, and stored it in a resource group called demorestore. I deliberately named the new managed disk after the VM that I am going to create.

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You can only create a new VM from a managed disk that contains an operating system. In the below screenshot, you can see that this disk contains Windows. If this is an OS disk, then you can click the magic button called + Create VM.

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What you are doing by clicking the button is shorting the usual Create Virtual Machine blade/wizard. A blade you probably know appears, but some of the features are greyed out because they’re already selected by choosing to create a VM from an existing managed disk.

Enter the name of the new VM, and select the resource group.

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In the Size blade, choose the size of the new VM. In settings, choose the availability set (key to restoring a VM to an availability set) and then all the other stuff like network, subnet, extensions, etc.

When you complete the wizard, a VM (which is just metadata) is created using your pre-existing OS managed disk. If you have any data disks to re-use, open Disks in the settings of the VM and add those managed disks with the required host caching mode. And that’s all there is to it!

Create an Azure Managed Disk from a VHD Blob

This post will show you how to create a managed disk from a VHD blob file, such as one you’ve uploaded or restored from a virtual machine backup. In my example, I have restored the virtual hard disks of an Azure VM to a storage account called aidanfinnrestore. I am going to create a new managed disk from the VHD blob, and (in another post) create a new VM from the managed disk that I am creating in this post.

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Open the Azure Portal, and go to Disks in the navigation bar on the left – this is where all managed disks are listed. Click + Add. A Create Manage Disk blade appears. Enter the following information:

  • Name: Give the new managed disk a name. My naming standard names the disk after the VM with a suffix to denote a role. In my example, it’s an OS disk.
  • Subscription: Select the subscription in your tenant. Note that you must create the managed disk in the same subscription as the storage account that contains the blob – you can always move the disk to a different subscription later.
  • Resource Group: Restore the disk to a new or existing resource group – typically this is where the virtual machine will be.
  • Location: Pick the region of the desired VM, which must also match the storage account.
  • Account Type: What kind of managed disk do you want – Standard (HDD) or Premium (SSD). You can change this later, one of the nice features of managed disks.
  • Source Type: I have selected Storage Blob – this is how the restored (or uploaded) VHD is stored.
  • Source Blob: Click browse, and navigate to & select the VHD blob that was restored/uploaded.
  • OS Type: If this is a data disk then select either Windows or Linux, depending on the guest OS in the VHD.
  • Size: To make like easy, select the size of the existing blob. I restored a managed disk to a blob, so I went with the original size of 128 GiB.

Once you’re happy with all the settings, click Create. In my case, with a 128 GiB VHD, the creation just around 30 seconds:

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Now you can either create a VM from the disk or attach it as a data disk to an existing VM in the Azure Portal – life is easy with managed disks!

Restore an Azure Virtual Machine’s Hard Disks

In this post, I’ll show you how to restore just the disks of an Azure virtual machine. This is useful if you want to restore a virtual machine to an availability set, or restore it as a different series/size.

Restoring to Availability Sets

For some reason that I do not know, we cannot restore a virtual machine to an availability set in Azure. It probably has something to do with the restriction in ARM that prevents a VM from being able to join an availability set after creation (vote for change here).

As a workaround, Azure Backup allows you to restore the disks, and then use those disks to create a new virtual machine (metadata) that is joined to the availability set. On the official docs pages, there is some pretty messy looking PowerShell to re-create the VM from those disks.

Thanks to some features of Managed Disks, if you have used managed disks for the VM, then you don’t need to go anywhere near that nasty PowerShell or JSON! I’ll post about that soon.

Restoring Disks

Browse to to the recovery services vault, open it, go to Backup Items > Azure Virtual Machine, and select the VM in question. Below is a screenshot of my web server in Azure. Click Restore VM.

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A blade with recovery points appears. Choose a restore point, i.e. a point in time from when you want to restore from, and click OK.

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The Restore Configuration blade appears. Choose Restore Disks as the Restore Type, and choose a storage account as the Staging Location. Click OK to start the backup job.

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Some time later, the disk(s) of the virtual machine are restored as blobs in a container in the storage account. You’ll also find a JSON file with details of the disk(s) that were restored.

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By the way, if you cannot tell which of the VHD blobs is your OS disk, download the JSON file and open it in Notepad (VS Code refuses to open it for me). The “osDisk” setting will tell you the path of the VHD blob that was the original data disk.

Microsoft’s solution would have you restore the virtual machine using PowerShell and that JSON file. I’ve read through it – it’s not pretty! My solution, in a later post, would create managed disks from the VHD blob(s), and then create a VM from the OS disk … and that’s nice and easy using the Azure Portal and a few mouse clicks.