3

I have a Storage Cluster consisting of 2 Windows Server 2016 Datacenter configured with a storage pool with 3 virtual disks consisting of the following physical disk.

 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : SSD FriendlyName : ATA VK0120GFDKE BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : SSD FriendlyName : ATA VK0120GFDKE BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : SSD FriendlyName : ATA VK0120GFDKE BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : HDD FriendlyName : HP EG0900JFCKB BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select
 MediaType    : SSD FriendlyName : ATA VK0120GFDKE BusType      : SAS    
 HealthStatus : Healthy Usage        : Auto-Select

When I run Get-ClusterStorageSpacesDirect command, I get the following warning:

WARNING: 2018/01 / 16-11: 11: 38.574 Node DB1: No disks found to be used for cache  
WARNING: 2018/01 / 16-11: 11: 38.580 Node DB2: No disks found to be used for cache

CacheMetadataReserveBytes: 34359738  
CacheModeHDD: ReadWrite  
CacheModeSSD: WriteOnly  
CachePageSizeKBytes: 16  
CacheState: Enabled  
State: Enabled 

I noticed that when I copy files, I only get to a speed between 80 - 90 MB

Why do I get the error that no disk was found for the cache but CacheState and State are Enabled? Can this be the reason that the copy speed is only about 90 MB?

Thank you for your help

4

You need to perform these steps:

1) Backup your data.

2) Disable S2D calling Disable-ClusterS2D cmdlet.

3) Clean disks. You'll need to run the script from here:

https://docs.microsoft.com/en-us/windows-server/storage/storage-spaces/hyper-converged-solution-using-storage-spaces-direct

icm (Get-Cluster -Name | Get-ClusterNode) { Update-StorageProviderCache Get-StoragePool | ? IsPrimordial -eq $false | Set-StoragePool -IsReadOnly:$false -ErrorAction SilentlyContinue Get-StoragePool | ? IsPrimordial -eq $false | Get-VirtualDisk | Remove-VirtualDisk -Confirm:$false -ErrorAction SilentlyContinue Get-StoragePool | ? IsPrimordial -eq $false | Remove-StoragePool -Confirm:$false -ErrorAction SilentlyContinue Get-PhysicalDisk | Reset-PhysicalDisk -ErrorAction SilentlyContinue Get-Disk | ? Number -ne $null | ? IsBoot -ne $true | ? IsSystem -ne $true | ? PartitionStyle -ne RAW | % { $_ | Set-Disk -isoffline:$false $_ | Set-Disk -isreadonly:$false $_ | Clear-Disk -RemoveData -RemoveOEM -Confirm:$false $_ | Set-Disk -isreadonly:$true $_ | Set-Disk -isoffline:$true } Get-Disk |? Number -ne $null |? IsBoot -ne $true |? IsSystem -ne $true |? PartitionStyle -eq RAW | Group -NoElement -Property FriendlyName } | Sort -Property PsComputerName,Count

5) Re-enabling S2D calling Enable-ClusterS2D cmdlet.

6) Restore your production data.

This should do the trick.

P.S. Think twice before putting two-node S2D cluster into production: Resilience isn't there AT ALL, it can't survive second disk failure in a row, or any (node or disk) failure during one node being down for patching or whatever. Microsoft started S2D with 4 nodes initially for a good reason, VMware vSAN is on the same page with S2D here.

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3

I tend to agree with @BaronSamedi1958 that s2d is far from considering as 'production-ready' (not to mention 2 node config which suffers from very low level of data protection). Maybe that's why Microsoft is being banned their 'brainchild' from production use. In any case, the new version will be released March 2018 at the earliest. Until then I'd avoid wasting my time trying to configure a solution that is simply in a very raw state right now. Especially, there's a lot of alternatives.

Look at HPE VSA and Starwind free. If I'm not mistaken, they both can do 2 node clusters and offering support, at least.

Honestly speaking, I may lack experience in using them, but waht I can say for sure is that Starwind, for instance, is doing proper resiliency on 2 nodes providing local storage redundancy by utilizing hardware RAID + redundancy at the nodes level (network mirroring). And certainly it is Web GUI, DRAM/flash caching and tons of technical papers... in short, what all good software-defined storages must do IMHO.

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