I'm testing S2D. I have created cluster from 2 VMs and call PowerShell

Enable-ClusterStorageSpacesDirect -SkipEligibilityChecks -Confirm -CacheState Disabled

List of storage

Type Node Size  Used Percent
---- ---- ----  ---- -------
HDD  1    21GB     0 0%
HDD  1    129GB    0 0%
HDD  1    107GB    0 0%
HDD  1    140GB    0 0%
HDD  1    118GB    0 0%
HDD  1    11GB     0 0%
HDD  2    21GB     0 0%
HDD  2    129GB    0 0%
HDD  2    107GB    0 0%
HDD  2    118GB    0 0%
HDD  2    140GB    0 0%
HDD  2    11GB     0 0%

In Failover Manager I can see that S2D Clustered Windows Storage has 986 GB free space, but when I try to create new volume, the maximum available capacity is 51 GB. I would expect ~490 GB. Any clues why the maximum is such low? Which steps am I missing?

Update Adding extra 300 GB drive to each VM increased free space to 1.51 TB and maximum volume size to 63 GB. Still not satisfied with the result.


I vote for shared storage. For the case, StarWind Virtual SAN Free seems to be a better option. Microsoft Storage Spaces Direct are more about Enterprise having requirements to underlying storage and Windows Server's licenses. https://technet.microsoft.com/en-us/windows-server-docs/storage/storage-spaces/choosing-drives

From my perspective, StarWind Virtual SAN would work here better since does not have mandatory requirements to underlying storage and provide shared storage on top of underlying with less to none penalty to both performance and capacity. https://www.starwindsoftware.com/starwind-virtual-san-free

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  • 1
    Thanks for pointing me to this product. I was evaluating it before, but a year ago the free version contained only 2 nodes without HA solution. – Jan Zahradník Apr 4 '17 at 9:04
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    It looks like they offer 2-node HA for free now. – Mr. Raspberry Apr 4 '17 at 10:03

S2D needs some free spaces to self-heal it in case of a disaster.


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  • I have read the article too, but i expect the reserved space about 5% or the size of the largest disk (240GB), not 95%. – Jan Zahradník Apr 1 '17 at 6:02

Thanks to @CosmosDarwin who helped me to find that the error was in Failover Manager. PowerShell script

New-Volume -FriendlyName "TEST" -FileSystem CSVFS_ReFS -StoragePoolFriendlyName S2D* -Size 200GB

created the volume without any problems. Worth to note is that New-Volume cmdlet prints volume info when succeeded, but has no output when fails because is not running with Administrative privileges.

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