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2018/07/04

Remove Node

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The following Demo are performed in a S2D test environment with 6 Cluster Nodes.
Each Node have 5 SSDs used for the Storage Pool.

If you dont have access to Physical Lab Servers you can use WSLab and get some more information from the Scenarios


Task:
Remove Node from Cluster. Retire the Disk before the Node is removed.
(Note: The Node have a Hardware problem so it only list 4 of 5 SSDs and need to be replaced)

Columns:
Know you Columns count and free Disk space, before you start to remove Disk/Nodes. 
  • 6x5=30 Physical Disk
All vDisk are created with the default maximum columns count of 8 and 3 way Mirror
  • 3x8=24 Disk used for every Extents
When we remove a Cluster Node we go from 30 Physical disk to 25 Physical Disk so the Columns of 8 (Need 24 Disk) will not impact the Performance if we have free space on the remaining Physical Disk.

Before we remote the Node we create a new vDisk to follow the Extents 

PowerShell:
New-Volume -StoragePoolFriendlyName S2D* -FriendlyName vDisk4 -FileSystem CSVFS_ReFS -ProvisioningType Fixed -Size 200GB -Verbose
Get-VirtualDisk "vDisk4"
$VirtualDisk4 = Get-VirtualDisk "vDisk4"
$Extents4 = Get-VirtualDisk "vDisk4" | Get-PhysicalExtent | Where VirtualDiskUniqueId -Eq $VirtualDisk4.UniqueId
$Extents4 | Group OperationalStatus -NoElement
$Extents4 | Group CopyNumber -NoElement
$Extents4 | Group Size -NoElement


# Show the first Columns of Extents and Copyes (8x3=24)
Get-VirtualDisk "vDisk4" | Get-PhysicalExtent | Select-Object -First 24 

  1. Create a 200 GB vDisk (With the size information from below we need 200 Extents to create a 200GB vDisk)
  2. Show the total of Extents (3 way Mirror then we have 3x200 = 600 Extents)
  3. Show each copy of the Extents (200 in copy 0, 200 in copy 1 and 200 in copy 2)
    • The default will be 0,1,2 in a 3 way Mirror.
    • When we start to remove Disk/Node we will see copy 3,4 more information below
  4. Show the size of one of the Extents (1073741824 Bytes = 1024MB or 1GB)

The Cluster Node S047023 have some problems with one Physical Disk (The node only list 4 of the 5 Disks installed and need to be replaced)


Node S047023 only list the 4 of 5 diske. All 4 Disk are listed as Retired


After the Physical Disk have 0% of the Extents (Only 4 of 5 listed do to Hardware Problem and the Node need to be replaced)


Now it is time to remove the Node S047023 from the Cluster





  1. Show the Extents 600 Active Extents before retire the disk
  2. List the Extents in each Copy
  3. List the Storage job when the DIsks are retired
  4. List the Copy number in the process of the retire