Increase the usable storage space in your Azure Stack environment


I have some tips for people who are running out of space or just want to have more space in their Azure Stack environment. The Azure Stack installation script intentionally leaves some space in the S2D (Storages Spaces Direct) ‘SU1_Pool’ for extending,rebuilding and maintenance purposes. You can use the remaining space to extend the virtual disk, but only if you do not have the plan to add extra physical drives for this Azure Stack deployment in the future. Otherwise, you have to add the new drives first and then extend the ‘virtual disk’, do not extend the virtual disk before you have added the new physical disks. The reason behind this is because the virtual disk cant be extended with space from newly added disks when you already used up all the available space in the storage pool. S2D cant redistribute the extents to newly added disks when there is no remaining space left on the existing physical disks. Therefore, I recommend to add new disks first and then resize/extend the virtual disk. Not planning to add new disks for this deployment? Then go ahead and use all the remaining space in the ‘SU1_Pool’ to extend the ‘SU1_Volume_1’ virtual disk.

Extend the virtual disk

Of course you can check out the disks and their sizes via server manager, however, if you want to have a good overview via PowerShell then execute the commands below.

After you have verified your configuration, number of physical disks and current sizes  then go ahead and resize the virtual disk. You can do this with PowerShell or more easily with ‘Server Manager’. In Server Manager go to ‘File and Storage Services -> Volume -> Storage Pools ‘ and right click the virtual disk ‘SU1_Volume_1’, now extend it to its maximum size.

Server Manager – File and Storage Services – Volume – Storage Pools











Use PowerShell if the ‘extend virtual disk’ option is not available (greyed out) or if the GUI reports that it there is no space left to extend the virtual disk when there clearly is remaining space left in the ‘SU1_Pool’.

PowerShell- Resize Virtual Disk




If you experience the ‘not enough storage’ error then try to resize with small increments (10GB) on top of the existing virtual disk size. Build that up until you used the maximum virtual disk size, this size is close to the maximum size of the pool. If you added new physical disks and still got errors with PowerShell or Server Manager then wait a few hours. That gives the system time to redistribute and rebalance the extents from the existing disks onto the new disks, it should allow you to extend again. If that still fails, then as a last step try to execute the PowerShell command ‘Optimize-StoragePool -FriendlyName ‘SU1_Pool’ and try again.

Extend Partition

When you successfully extended the virtual disk then you also need to extend the volume/partition, you can do this via server manager or disk management but of course its always more easy to do it via PowerShell. Below are the PowerShell commands, no input needed.

Verify the new storage space with the last PowerShell command above. The MAS-ACS01 or the Host NEED to be restarted after you extended or modified the partition in any way.  Extending the partition/volume triggers a bug in one of the ServiceFabric hosted applications, the Marketplace is broken (gallery artifacts) and you will see ‘nocdn’ in the address bar. Restart MAS-ACS01 and see if the issue is resolved. Otherwise, restart the Host and wait twenty minutes or so for the fabric VMs to come up, the ‘ColdStartMachine’ scheduled task at startup will start them in the right order.

Now go to the portal and see the newly added space in the capacity view of the Azure Stack Storage RP. Tip: Pin the ‘storage capacity’ view to the portal’s dashboard, its very useful,  you see the usage every time you login.

Thats it! Also, dont forget to change the retention period for the storage accounts and run the Azure Stack post-deployment script, it fixes several TP2 storage space consumption issues.

Happy Stacking,


Thanks to Darry van der Peijl for support in troubleshooting the inner workings of S2D.

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  • James Bond

    Can anyone provide information on how much storage space and memory Azure Stack TP3 consumes on a single-node POC configuration? This will hopefully allow me to estimate the amount of remaining server memory and storage space that would be “leftover” for testing guest VMs.

    • Christian M

      Memory wise it’s about 77gb, can’t tell you the amount of space it takes up since my installation is reinitialising right now, and that takes forever apparently…