Hi,
I'll preface this with I've not worked with storage spaces until a like 2 days ago. I wanted to see how it performed in server 2016. I'm working my way through basic mirrors, onto write-back cache/read cache, and tiered storage. I'm NOT doing S2D testing (not interested until the licensing drops significantly).
So I created a mirror of 4 SSD, strictly default settings (2 columns, default wbc, etc). When running AS-SSD I see similar performance to what I'd get with a cachless RAID card, expect for 4K. 4K writes are, at best, HALF of what they should be and, if I remember correctly, the reads were also not where they should have been.
The disks are 960GB Samsung PM853T.
Something is telling me this might be an issue with sector sizes...? That link says that all SSD's are 4k, but these are not showing that way.
And this is what the vDisk looks like after creation.
I do the following to create the pool and mirrored vdisk of SSD's. I have tested with NTFS and explicitly setting the type of provisioning and it made no difference.
#Create storage pool from all 4 SSD's
New-StoragePool -FriendlyName "vmpool" -StorageSubSystemUniqueId (Get-StorageSubSystem -FriendlyName "Windows Storage*").UniqueId -PhysicalDisks (Get-PhysicalDisk -CanPool $true | ? MediaType -eq "SSD")
#Create mirrored vDisk using all the space on the SSD's
New-VirtualDisk -FriendlyName "SSD_datastore01" -StoragePoolFriendlyName "vmpool" -UseMaximumSize -ResiliencySettingName Mirror
#Get vDisk number
Get-VirtualDisk -FriendlyName "SSD_datastore01" | Get-Disk
#Initialize disk
Initialize-Disk -Number 9
#Add partition to disk
New-Partition -DiskNumber 9 -UseMaximumSize -AssignDriveLetter
#Format partition
Format-Volume -DriveLetter E -FileSystem ReFS -NewFileSystemLabel "SSD_Datastore01"
I'll preface this with I've not worked with storage spaces until a like 2 days ago. I wanted to see how it performed in server 2016. I'm working my way through basic mirrors, onto write-back cache/read cache, and tiered storage. I'm NOT doing S2D testing (not interested until the licensing drops significantly).
So I created a mirror of 4 SSD, strictly default settings (2 columns, default wbc, etc). When running AS-SSD I see similar performance to what I'd get with a cachless RAID card, expect for 4K. 4K writes are, at best, HALF of what they should be and, if I remember correctly, the reads were also not where they should have been.
The disks are 960GB Samsung PM853T.
Something is telling me this might be an issue with sector sizes...? That link says that all SSD's are 4k, but these are not showing that way.
Code:
Get-PhysicalDisk | select FriendlyName, Manufacturer, Model, PhysicalSectorSize, LogicalSectorSize | ft
FriendlyName Manufacturer Model PhysicalSectorSize LogicalSectorSize
------------ ------------ ----- ------------------ -----------------
ATA SAMSUNG MZ7GE960 ATA SAMSUNG MZ7GE960 512 512
ATA SAMSUNG MZ7GE960 ATA SAMSUNG MZ7GE960 512 512
ATA SAMSUNG MZ7GE960 ATA SAMSUNG MZ7GE960 512 512
ATA SAMSUNG MZ7GE960 ATA SAMSUNG MZ7GE960 512 512
And this is what the vDisk looks like after creation.
Code:
Get-VirtualDisk | select FriendlyName, PhysicalSectorSize, LogicalSectorSize | ft
FriendlyName PhysicalSectorSize LogicalSectorSize
------------ ------------------ -----------------
SSD_datastore01 4096 512
#Create storage pool from all 4 SSD's
New-StoragePool -FriendlyName "vmpool" -StorageSubSystemUniqueId (Get-StorageSubSystem -FriendlyName "Windows Storage*").UniqueId -PhysicalDisks (Get-PhysicalDisk -CanPool $true | ? MediaType -eq "SSD")
#Create mirrored vDisk using all the space on the SSD's
New-VirtualDisk -FriendlyName "SSD_datastore01" -StoragePoolFriendlyName "vmpool" -UseMaximumSize -ResiliencySettingName Mirror
#Get vDisk number
Get-VirtualDisk -FriendlyName "SSD_datastore01" | Get-Disk
#Initialize disk
Initialize-Disk -Number 9
#Add partition to disk
New-Partition -DiskNumber 9 -UseMaximumSize -AssignDriveLetter
#Format partition
Format-Volume -DriveLetter E -FileSystem ReFS -NewFileSystemLabel "SSD_Datastore01"
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