Azure Managed Disk

Azure的磁盘存储是保存在存储账户中的Page Blob。由于Azure Storage Account的各种限制，在设计VM的磁盘存储时，要符合Azure磁盘存储账户的最佳实践，请参考：http://www.cnblogs.com/hengwei/p/6377598.html

目前Global已经发布了Managed Disk，就是把各种Storage Account的限制封装起来。用户在使用VM Disk时，不用再考虑各种Storage Account的限制。

在非Managed Disk情况下，需要考虑Storage Account：

在Managed Disk情况下，不需要再考虑Storage Account了：

本文将探讨，如何采用Managed Disk创建VM，已经如何将Unmanaged Disk转换成Managed Disk。

一、采用Managed Disk创建VM

1. 在Portal上创建Managed Disk的VM

   在Portal上创建Managed Disk的VM和创建普通的VM相似，只是在选择存储信息的时候，选择Managed Disk选项就OK了。具体如下：

   1. VM基本信息

   

   1. 选择VM Size

   

   1. 配置可选功能

   

   其中和存储相关的亮相：1. Disk，选择Managed Disk，2. 诊断，选择普通的存储账户。

   一路确定下，Managed Disk的VM就创建好了。

   创建完成后，可以看到VM和其Disk的状态：

   

   在VM内，观察磁盘，

   [root@hwmdtest ~]# fdisk /dev/sda
   Welcome to fdisk (util-linux 2.23.).
   Changes will remain in memory only, until you decide to write them.
   Be careful before using the write command.
   Command (m for help): p
   Disk /dev/sda: 32.2 GB,  bytes,  sectors
   Units = sectors of  *  =  bytes
   Sector size (logical/physical):  bytes /  bytes
   I/O size (minimum/optimal):  bytes /  bytes
   Disk label type: dos
   Disk identifier: 0x000c7b1d
   Device Boot Start End Blocks Id System
   /dev/sda1 *     Linux
   /dev/sda2     Linux
   Command (m for help): ^C
   
   进行IOPS的测试：
   [root@hwmdtest ~]# ./iops.py /dev/sda
   /dev/sda, 32.21 G, sectorsize=512B, #threads=, pattern=random:
    B blocks: 560.3 IO/s, 286.9 kB/s ( 2.3 Mbit/s)
    kB blocks: 476.4 IO/s, 487.8 kB/s ( 3.9 Mbit/s)
    kB blocks: 415.7 IO/s, 851.4 kB/s ( 6.8 Mbit/s)
    kB blocks: 299.1 IO/s, 1.2 MB/s ( 9.8 Mbit/s)
    kB blocks: 289.4 IO/s, 2.4 MB/s ( 19.0 Mbit/s)
    kB blocks: 294.2 IO/s, 4.8 MB/s ( 38.6 Mbit/s)
    kB blocks: 291.1 IO/s, 9.5 MB/s ( 76.3 Mbit/s)
    kB blocks: 286.5 IO/s, 18.8 MB/s (150.2 Mbit/s)
    kB blocks: 210.5 IO/s, 27.6 MB/s (220.7 Mbit/s)
    kB blocks: 192.3 IO/s, 50.4 MB/s (403.2 Mbit/s)
    kB blocks: 105.2 IO/s, 55.2 MB/s (441.4 Mbit/s)
    MB blocks: 56.7 IO/s, 59.4 MB/s (475.6 Mbit/s)
    MB blocks: 31.6 IO/s, 66.2 MB/s (529.6 Mbit/s)
    MB blocks: 19.4 IO/s, 81.5 MB/s (651.9 Mbit/s)
    MB blocks: 15.9 IO/s, 133.3 MB/s ( 1.1 Gbit/s)
    MB blocks: 7.7 IO/s, 129.5 MB/s ( 1.0 Gbit/s)

   大约在500IOPS左右。

2. 用Azure CLI创建VM

   用CLI创建一台CentOS的VM：

   az vm create -n hwmdcli --resource-group hwmd --admin-username hengwei \ 
       --admin-password xxxxxxxx --authentication-type password \
       --storage-sku Standard_LRS --size Standard_D1 --subnet default \
       --vnet-name hwmd-vnet --image CentOS
   
   {- Finished ..
   "fqdns": "",
   "id": "/subscriptions/xxxx/resourceGroups/hwmd/providers/Microsoft.Compute/virtualMachines/hwmdcli",
   "location": "eastasia",
   "macAddress": "00-0D-3A-81-C9-7F",
   "powerState": "VM running",
   "privateIpAddress": "10.1.0.5",
   "publicIpAddress": "52.229.175.38",
   "resourceGroup": "hwmd"
   }

   

二、磁盘的转换

1. VM从Unmanaged Disk转换成Managed Disk

   创建一台Unmanaged Disk的VM：hwumd。然后用Azure CLI对VM进行转换：

   • Deallocate VM

     az vm deallocate -g hwmd -n hwumd
     
     {/ Finished ..
     "endTime": "2017-06-12T08:07:49.459038+00:00",
     "error": null,
     "name": "222f9f03-b23e-4359-ba07-4195840b68de",
     "startTime": "2017-06-12T08:05:48.453632+00:00",
     "status": "Succeeded"
     }

   • Convert Disk

     az vm convert -g hwmd -n hwumd
     
     {| Finished ..
     "endTime": "2017-06-12T08:14:23.519972+00:00",
     "error": null,
     "name": "cbe7b1ae-339d-415a-b4e7-c93c37ea7872",
     "startTime": "2017-06-12T08:13:31.748733+00:00",
     "status": "Succeeded"
     }

   • 此时可以看到Disk已经转换成Managed Disk：

   • az vm show -g hwmd -n hwumd
     
     {
     
     ......
     "osDisk": {
     "caching": "ReadWrite",
     "createOption": "fromImage",
     "diskSizeGb": ,
     "encryptionSettings": null,
     "image": null,
     "managedDisk": {
     "id": "/subscriptions/……/resourceGroups/hwmd/providers/Microsoft.Compute/disks/hwumd_hwumd",
     "resourceGroup": "hwmd",
     "storageAccountType": "Standard_LRS"
     },
     "name": "hwumd_hwumd",
     "osType": "Linux",
     "vhd": null
     }
     },
     ......
     }

2. 普通的Managed Disk转换成Premium的Managed Disk

1. • 首先Deallocate VM

     az vm deallocate -g hwmd -n hwumd
     {| Finished ..
       "endTime": "2017-06-12T08:29:53.044297+00:00",
       "error": null,
       "name": "629d3b3e-78f7-4fb4-b6bb-aa4785c71123",
       "startTime": "2017-06-12T08:27:46.205233+00:00",
       "status": "Succeeded"
     }

   • Resize VM

     az vm resize -g hwmd -n hwumd --size Standard_DS2
     {- Finished ..
       ……
         "osDisk": {
           "caching": "ReadWrite",
           "createOption": "fromImage",
           "diskSizeGb": null,
           "encryptionSettings": null,
           "image": null,
           "managedDisk": {
             "id": "/subscriptions/……/resourceGroups/hwmd/providers/Microsoft.Compute/disks/hwumd_hwumd",
             "resourceGroup": "hwmd",
             "storageAccountType": null
           },
           "name": "hwumd_hwumd",
           "osType": "Linux",
           "vhd": null
         }
       },
     ……
     }

   • 改变Disk的类型到Premium

     az disk update -g hwmd -n hwumd_hwumd --sku Premium_LRS
     {
       "accountType": "Premium_LRS",
       "creationData": {
         "createOption": "Import",
         "imageReference": null,
         "sourceResourceId": null,
         "sourceUri": "https://hwmddiag954.blob.core.windows.net/vhds/hwumd20170612152358.vhd",
         "storageAccountId": null
       },
       "diskSizeGb": ,
       "encryptionSettings": null,
       "id": "/subscriptions/……/resourceGroups/hwmd/providers/Microsoft.Compute/disks/hwumd_hwumd",
       "location": "eastasia",
       "name": "hwumd_hwumd",
       "osType": null,
       "ownerId": "/subscriptions/……/resourceGroups/hwmd/providers/Microsoft.Compute/virtualMachines/hwumd",
       "provisioningState": "Succeeded",
       "resourceGroup": "hwmd",
       "tags": null,
       "timeCreated": "2017-06-12T08:13:37.322385+00:00",
       "type": "Microsoft.Compute/disks"
     }

   • 重新启动VM

     此时VM已经升级到DS2的高级存储类型的VM了。

三. 总结

通过简单的Azure Cli，可以把磁盘转换成Managed Disk。转成Managed Disk的好处是不需要再关心存储账户的各种限制。

另外，VM变成Premium的DS系列后，可以挂载普通或者高级的磁盘。实现下图的各种挂载磁盘选项：