This post is about setting up a Server 2012 R2 failover cluster that acts as an iSCSI target server.
I have four servers: WIN-DATA01, WIN-DATA02, WIN-DATA03, WIN-DATA04. I will be putting WIN-DATA03 & WIN-DATA04 in the cluster. As you know clusters required shared storage so that’s what WIN-DATA01 and WIN-DATA02 is for. In a real world setup WIN-DATA01 & WIN-DATA02 are your SAN boxes whose storage you want to make available to clients. Yes you could have clients access the two SAN boxes directly, but by having a cluster in between you can provide failover. Plus, Windows now has a cool thing called Storage Pools which let you do software RAID sort of stuff.
Prepare the iSCSI target server
First step, prepare the iSCSI target servers that will provide storage for the cluster. The steps for this are in my previous post so very briefly here’s what I did:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 |
PS> New-IscsiServerTarget -TargetName LUN1 -InitiatorIds Iqn:iqn.1991-05.com.microsoft:win-data03.rakhesh.local,Iqn:iqn.1991-05.com.microsoft:win-data04.rakhesh.local ChapUserName : ClusterGroupName : ComputerName : WIN-DATA01.rakhesh.local Description : EnableChap : False EnableReverseChap : False EnforceIdleTimeoutDetection : True FirstBurstLength : 65536 IdleDuration : 00:00:00 InitiatorIds : {Iqn:iqn.1991-05.com.microsoft:win-data03.rakhesh.local, Iqn:iqn.1991-05.com.microsoft:win-data04.rakhesh.local} LastLogin : LunMappings : {} MaxBurstLength : 262144 MaxReceiveDataSegmentLength : 65536 ReceiveBufferCount : 10 ReverseChapUserName : Sessions : {} Status : NotConnected TargetIqn : iqn.1991-05.com.microsoft:win-data01-lun1-target TargetName : LUN1 PS> New-IscsiVirtualDisk -Path E:\WIN-DATA01-LUN1.vhdx -SizeBytes 60GB ClusterGroupName : ComputerName : WIN-DATA01.rakhesh.local Description : DiskType : Dynamic HostVolumeId : {C19510A5-9CB1-11E3-80C8-000C29C89404} LocalMountDeviceId : OriginalPath : ParentPath : Path : E:\WIN-DATA01-LUN1.vhdx SerialNumber : 31D1214B-D866-4B2E-9B98-6D44648D2B2A Size : 64424509440 SnapshotIds : Status : NotConnected VirtualDiskIndex : 1521008525 PS> Add-IscsiVirtualDiskTargetMapping -TargetName LUN1 -Path E:\WIN-DATA01-LUN1.vhdx |
Repeat the above for the other server (you can login to that server and issue commands, or do remotely like I did below). Everything’s same as above except for the addition of the -ComputerName switch.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 |
PS> New-IscsiServerTarget -TargetName LUN1 -InitiatorIds Iqn:iqn.1991-05.com.microsoft:win-data03.rakhesh.local,Iqn:iqn.1991-05.com.microsoft:win-data04.rakhesh.local -ComputerName WIN-DATA02 ChapUserName : ClusterGroupName : ComputerName : WIN-DATA02.rakhesh.local Description : EnableChap : False EnableReverseChap : False EnforceIdleTimeoutDetection : True FirstBurstLength : 65536 IdleDuration : 00:00:00 InitiatorIds : {Iqn:iqn.1991-05.com.microsoft:win-data03.rakhesh.local, Iqn:iqn.1991-05.com.microsoft:win-data04.rakhesh.local} LastLogin : LunMappings : {} MaxBurstLength : 262144 MaxReceiveDataSegmentLength : 65536 ReceiveBufferCount : 10 ReverseChapUserName : Sessions : {} Status : NotConnected TargetIqn : iqn.1991-05.com.microsoft:win-data02-lun1-target TargetName : LUN1 PS> New-IscsiVirtualDisk -Path E:\WIN-DATA02-LUN1.vhdx -SizeBytes 60GB -ComputerName WIN-DATA02 ClusterGroupName : ComputerName : WIN-DATA02.rakhesh.local Description : DiskType : Dynamic HostVolumeId : {B012F108-9CB1-11E3-80C8-000C2940DF92} LocalMountDeviceId : OriginalPath : ParentPath : Path : E:\WIN-DATA02-LUN1.vhdx SerialNumber : 0C57616B-73E3-4DEC-B43F-E1EC9353D52C Size : 64424509440 SnapshotIds : Status : NotConnected VirtualDiskIndex : 281317843 PS> Add-IscsiVirtualDiskTargetMapping -TargetName LUN1 -Path E:\WIN-DATA02-LUN1.vhdx -ComputerName WIN-DATA02 |
Excellent!
Now let’s move on to the two servers that will form the cluster.
Add shared storage to the servers
Here we add the two iSCSI targets created above to the two servers WIN-DATA03 & WIN-DATA04.
Login to one of the servers, open Server Manager > Tools > iSCSI Initiator.
Easiest option is to enter WIN-DATA01 in the Target field and click Quick Connect. That should list the targets on this server in the Discovered targets box. Select the ones you want and click Connect.
Another option is to go to the Discovery tab.
Click Discover Portal, enter the two server names (WIN-DATA01, WIN-DATA02), refresh (if needed), and then the first tab will automatically show all targets on these two servers. Select the ones you want and click Connect as before.
The GUI sets these connections as persistent (it calls them “Favorite Target”) so they are always reconnected when the server reboots.
You can also use PowerShell to add these connections though that isn’t as easy as this point and click. Instructions are in my earlier post so here they are briefly:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 |
PS> New-IscsiTargetPortal -TargetPortalAddress WIN-DATA01 InitiatorInstanceName : InitiatorPortalAddress : IsDataDigest : False IsHeaderDigest : False TargetPortalAddress : WIN-DATA01 TargetPortalPortNumber : 3260 PSComputerName : PS> New-IscsiTargetPortal -TargetPortalAddress WIN-DATA02 InitiatorInstanceName : InitiatorPortalAddress : IsDataDigest : False IsHeaderDigest : False TargetPortalAddress : WIN-DATA02 TargetPortalPortNumber : 3260 PSComputerName : PS> Get-IscsiTarget IsConnected NodeAddress PSComputerName ----------- ----------- -------------- False iqn.1991-05.com.microsoft:win-data01... False iqn.1991-05.com.microsoft:win-data02... PS> Get-IscsiTarget | ft -AutoSize IsConnected NodeAddress PSComputerName ----------- ----------- -------------- False iqn.1991-05.com.microsoft:win-data01-lun1-target False iqn.1991-05.com.microsoft:win-data02-lun1-target PS> Connect-IscsiTarget -NodeAddress iqn.1991-05.com.microsoft:win-data01-lun1-target -IsPersistent $true AuthenticationType : NONE InitiatorInstanceName : ROOT\ISCSIPRT\0000_0 InitiatorNodeAddress : iqn.1991-05.com.microsoft:win-data04.rakhesh.local InitiatorPortalAddress : 0.0.0.0 InitiatorSideIdentifier : 400001370000 IsConnected : True IsDataDigest : False IsDiscovered : False IsHeaderDigest : False IsPersistent : True NumberOfConnections : 1 SessionIdentifier : ffffe00002a3b430-4000013700000016 TargetNodeAddress : iqn.1991-05.com.microsoft:win-data01-lun1-target TargetSideIdentifier : 0200 PSComputerName : PS> Connect-IscsiTarget -NodeAddress iqn.1991-05.com.microsoft:win-data02-lun1-target -IsPersistent $true AuthenticationType : NONE InitiatorInstanceName : ROOT\ISCSIPRT\0000_0 InitiatorNodeAddress : iqn.1991-05.com.microsoft:win-data04.rakhesh.local InitiatorPortalAddress : 0.0.0.0 InitiatorSideIdentifier : 400001370000 IsConnected : True IsDataDigest : False IsDiscovered : False IsHeaderDigest : False IsPersistent : True NumberOfConnections : 1 SessionIdentifier : ffffe00002a3b430-4000013700000017 TargetNodeAddress : iqn.1991-05.com.microsoft:win-data02-lun1-target TargetSideIdentifier : 0200 PSComputerName : |
Unlike the GUI, PowerShell does not mark these targets as persistent so I have to specify that explicitly when connecting.
Prepare the shared storage
The shared storage we added is offline and needs to be initialized. You can do this via the Disk Management UI or using PowerShell as below. The initializing bits need to be done on any one server only (WIN-DATA03 or WIN-DATA04) but you have to make the disks online on both servers.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 |
PS> get-disk Number Friendly Name OperationalStatus Total Size Partition Style ------ ------------- ----------------- ---------- --------------- 0 VMware, VMware Virtual S SCSI Disk De... Online 60 GB MBR 2 MSFT Virtual HD SCSI Disk Device Offline 60 GB RAW 1 VMware, VMware Virtual S SCSI Disk De... Online 60 GB MBR 3 MSFT Virtual HD SCSI Disk Device Offline 60 GB RAW PS> Set-Disk -Number 2 -IsOffline $false PS> Set-Disk -Number 3 -IsOffline $false PS> Initialize-Disk -Number 2 -PartitionStyle MBR PS> Initialize-Disk -Number 3 -PartitionStyle MBR |
Create the cluster
Login to one of the servers that will form the cluster, open Server Manager, go to Tools > Failover Cluster Manager and click Create Cluster on the right side (the Actions pane). This launches the Create Cluster Wizard.
Click Next on the first screen, enter the server names on the second …
… do or don’t do the validation tests (I skipped as this is a lab setup for me), give a name for the cluster and an IP address, confirm everything (I chose to not add all eligible storage just so I can do that separately), and that’s it.
Couple of things to note here:
- If your cluster servers don’t have any interfaces with DHCP configured, you will also be prompted for an IP address. Otherwise a DHCP address is automatically assigned. (In my case I had an interface with DHCP).
- A computer object with the cluster server name you specify is created in the same OU as the servers that make up the cluster. You can specify a different OU by giving the full name as the cluster name – so in the example above I would use “CN=WIN-CLUSTER01,OU=Clusters,OU=Server,DC=rakhesh,DC=local” to create the object in the Clusters OU within the Servers OU. Would have been good if the wizard mentioned that.
- Later, when you add roles to this cluster server, it creates more virtual servers automatically. These are placed in the same OU where the cluster server object is so you must give this object rights to add/ remove computers in that OU. So it’s best you have a separate OU which you can delegate rights to. I used the Delegation Control Wizard to give the WIN-CLUSTER01 object full control over Computer Objects in the rakhesh.local/Servers/Clusters OU.
Instead of the Create Cluster Wizard one can use PowerShell as below:
|
1 2 3 4 5 6 7 8 |
# skip the -NoStorage switch to automatically add storage # specify a full name for the cluster name if you want to place in a different OU PS> New-Cluster -Name WIN-CLUSTER01 -Node WIN-DATA03,WIN-DATA04 -NoStorage Report file location: C:\Windows\cluster\Reports\Create Cluster Wizard WIN-CLUSTER01 on 2014.02.25 At 09.44.50.mht Name ---- WIN-CLUSTER01 |
Configuring the cluster
A cluster has many resources assigned to it. Resources such as disks, networks, and its name. These can be seen in the summary page of the cluster or via PowerShell.
|
1 2 3 4 5 6 7 |
# if you have many clusters specify the -Cluster <clustername> switch here PS> Get-ClusterResource Name State OwnerGroup ResourceType ---- ----- ---------- ------------ Cluster IP Address Online Cluster Group IP Address Cluster Name Online Cluster Group Network Name |
Network
I am interested in changing the IP address of my cluster. Currently it’s taken an IP from the DHCP pool and I don’t want that. Being a lab setup both my servers had a NAT interface to connect to the outside world and so the cluster is currently picking up an IP from that. I want it to use the internal network instead.
If I right click on IP address resource I can change it.
In my case I don’t want to use this network itself so I have to go to the Networks section in the UI …
… where I can see there are two networks specified, with one of them having no cluster use while the other is configured for cluster & client use, so I right click on the first network and …
… enable it for cluster access, then I right click on the second network and …
… rename it (for my reference) as well as disable it from the cluster.
Now if I go to the resources section and right click the IP address, I can select the second network and assign a static IP address.
Here’s how to do the above via PowerShell.
To change the network name use the Get-ClusterNetwork to select the network you want (the result is an object) and directly assign the new name as a value:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 |
PS> Get-ClusterNetwork Name State ---- ----- Cluster Network 1 Up NAT Network Up PS> (Get-ClusterNetwork -Name "Cluster Network 1").Name = "Cluster Network" PS> Get-ClusterNetwork Name State ---- ----- Cluster Network Up NAT Network Up |
One would expect to be able to set IP addresses too via this, but unfortunately these are read-only properties (notice it only has the get method; properties which you can modify will also have the set method):
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 |
PS> Get-ClusterNetwork -Name "Cluster Network" | gm TypeName: Microsoft.FailoverClusters.PowerShell.ClusterNetwork Name MemberType Definition ---- ---------- ---------- Equals Method bool Equals(System.Object obj) GetHashCode Method int GetHashCode() GetType Method type GetType() ToString Method string ToString() Update Method void Update() Address Property string Address {get;} AddressMask Property string AddressMask {get;} AutoMetric Property bool AutoMetric {get;set;} Cluster Property Microsoft.FailoverClusters.PowerShell.Cluster Cluster {get;} Description Property string Description {get;set;} Id Property string Id {get;} Ipv4Addresses Property System.Object Ipv4Addresses {get;} Ipv4PrefixLengths Property System.Object Ipv4PrefixLengths {get;} Ipv6Addresses Property System.Object Ipv6Addresses {get;} Ipv6PrefixLengths Property System.Object Ipv6PrefixLengths {get;} Metric Property uint32 Metric {get;set;} Name Property string Name {get;set;} Role Property uint32 Role {get;set;} State Property Microsoft.FailoverClusters.PowerShell.ClusterNetworkState State {get;} |
To set the IP address via PowerShell we have to remember that we went to the Cluster Resource view to change it. So we do the same here. Use the Get-ClusterResource cmdlet.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 |
PS> Get-ClusterResource -Name "Cluster IP Address" | fl * Cluster : WIN-CLUSTER01 IsCoreResource : False IsNetworkClassResource : True IsStorageClassResource : False OwnerNode : WIN-DATA04 ResourceType : IP Address State : Online OwnerGroup : Cluster Group Name : Cluster IP Address MaintenanceMode : False MonitorProcessId : 1872 Characteristics : 0 Description : SeparateMonitor : False StatusInformation : 0 PersistentState : 1 LastOperationStatusCode : 0 LooksAlivePollInterval : 4294967295 IsAlivePollInterval : 4294967295 RestartAction : 2 RestartThreshold : 1 EmbeddedFailureAction : 2 RestartDelay : 500 RestartPeriod : 900000 RetryPeriodOnFailure : 3600000 PendingTimeout : 180000 DeadlockTimeout : 300000 ResourceSpecificData1 : 0 ResourceSpecificData2 : 0 ResourceSpecificStatus : Id : b00341a9-3fff-498f-bddf-3b909641ee73 |
That doesn’t totally help. What we need are the parameters of the resource, so we pipe that to the Get-ClusterParameter cmdlet.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 |
PS> Get-ClusterResource -Name "Cluster IP Address" | Get-ClusterParameter Object Name Value Type ------ ---- ----- ---- Cluster IP Address Network Cluster Network String Cluster IP Address Address 10.50.0.50 String Cluster IP Address SubnetMask 255.255.255.0 String Cluster IP Address EnableNetBIOS 1 UInt32 Cluster IP Address OverrideAddressMatch 0 UInt32 Cluster IP Address EnableDhcp 0 UInt32 Cluster IP Address ProbePort 0 UInt32 Cluster IP Address ProbeFailureThreshold 0 UInt32 Cluster IP Address LeaseObtainedTime 1/1/0001 12:00:00 AM DateTime Cluster IP Address LeaseExpiresTime 1/1/0001 12:00:00 AM DateTime Cluster IP Address DhcpServer 255.255.255.255 String Cluster IP Address DhcpAddress 0.0.0.0 String Cluster IP Address DhcpSubnetMask 255.0.0.0 String |
Perfect! And to modify these parameters use the Set-ClusterParameter cmdlet.
|
1 2 |
PS> Get-ClusterResource -Name "Cluster IP Address" | Set-ClusterParameter -Name "Address"-Value "10.50.0.51" WARNING: The properties were stored, but not all changes will take effect until Cluster IP Address is taken offline and then online again. |
To take the Cluster IP Address resource offline & online use the Stop-ClusterResource and Start-ClusterResource cmdlets:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 |
PS> Stop-ClusterResource "Cluster IP Address" Name State OwnerGroup ResourceType ---- ----- ---------- ------------ Cluster IP Address Offline Cluster Group IP Address PS> Start-ClusterResource "Cluster IP Address" Name State OwnerGroup ResourceType ---- ----- ---------- ------------ Cluster IP Address Online Cluster Group IP Address PS> Get-ClusterResource -Name "Cluster IP Address" | Get-ClusterParameter Object Name Value Type ------ ---- ----- ---- Cluster IP Address Network Cluster Network String Cluster IP Address Address 10.50.0.51 String Cluster IP Address SubnetMask 255.255.255.0 String Cluster IP Address EnableNetBIOS 1 UInt32 Cluster IP Address OverrideAddressMatch 0 UInt32 Cluster IP Address EnableDhcp 0 UInt32 Cluster IP Address ProbePort 0 UInt32 Cluster IP Address ProbeFailureThreshold 0 UInt32 Cluster IP Address LeaseObtainedTime 1/1/0001 12:00:00 AM DateTime Cluster IP Address LeaseExpiresTime 1/1/0001 12:00:00 AM DateTime Cluster IP Address DhcpServer 255.255.255.255 String Cluster IP Address DhcpAddress 0.0.0.0 String Cluster IP Address DhcpSubnetMask 255.0.0.0 String |
Although it doesn’t say so, you have to also stop and start the Cluster Name resource for the name to pick up the new IP address.
|
1 2 3 4 5 6 7 8 9 10 11 12 |
PS> Stop-ClusterResource "Cluster Name" Name State OwnerGroup ResourceType ---- ----- ---------- ------------ Cluster Name Offline Cluster Group Network Name PS> Start-ClusterResource "Cluster Name" Name State OwnerGroup ResourceType ---- ----- ---------- ------------ Cluster Name Online Cluster Group Network Name |
Lastly, to change whether a particular network is used for cluster communication or not, one can do the same technique that was used to change the host name. Just use the Role property. I am not sure what the values for it are, but from my two networks I can see that a value of 0 means it is not used for cluster communication, while a value of 3 means it is used for cluster communication and client traffic.
|
1 2 3 4 5 6 |
PS> Get-ClusterNetwork | ft Name,Role Name Role ---- ---- Cluster Network 3 NAT Network 0 |
The GUI is way easier than PowerShell for configuring this network stuff!
Storage (Disks)
Next I want to add disks to my cluster. Usually all available disks get added by default, but in this case I want to do it manually.
Right click Failover Cluster Manager > Storage > Disk and select Add Disk. This brings up a window with all the available disks. Since this is a cluster not every disk present on the system can be used. The disk must be something visible to all members of the cluster as it is shared by them.
Via PowerShell:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
PS> Get-ClusterAvailableDisk Name : Cluster Disk 1 Number : 2 Size : 64424509440 Id : 0x9B9C9B12 Cluster : WIN-CLUSTER01 Partitions : {} Name : Cluster Disk 2 Number : 3 Size : 64424509440 Id : 0x9B9C9B17 Cluster : WIN-CLUSTER01 Partitions : {} |
To add these disks to the cluster pipe the output to the Add-ClusterDisk cmdlet. There’s no way to select specific disks so you must either pipe the output to a Where-Object cmdlet first to filter the disks you want, or use the Get-Disk cmdlet (as it lets you specify a disk number) and pipe that to the Add-ClusterDisk cmdlet.
(I won’t be adding these disks to my cluster yet as I want to put them in a storage pool. I’ll be doing that in a bit).
Quorum
Quorum is a very important concept for clusters (see an earlier post of mine for more about quorum).
|
1 2 3 4 5 6 |
PS> Get-ClusterQuorum | fl * Cluster : WIN-CLUSTER01 QuorumResource : QuorumType : NodeMajority |
The cluster which I created is currently in the Node Majority mode. (Because I haven’t added and Disk or File Share witnesses to it). That’s not a good mode to be in so let’s change that.
Go to the Configure Cluster Quorum Settings as in the screenshot below, click Next …
… choose the second option (Select the quorum witness) and click Next …
… in my case I want to use a File Share witness so I choose that option and click Next …
… create a file share someplace, point to that, and click Next …
… click Next and then Finish.
Now it’s configured.
|
1 2 3 4 5 6 |
PS> Get-ClusterQuorum | fl * Cluster : WIN-CLUSTER01 QuorumResource : File Share Witness QuorumType : NodeAndFileShareMajority |
Storage (Pool)
(If you plan to create a storage pool add an extra shared disk to your cluster. I created a new target on the WIN-DATA02 & WIN-DATA01 server (no need for doing on both but I just did so it’s consistent), mapped another virtual disk to it, and used the iSCSI initiator on WIN-DATA03 & WIN-DATA04 to map it. Storage Pools on Failover Clusters require a minimum of three disks).
I want to use Storage Spaces (they are called Storage Pools in Failover Cluster Manager). Storage Spaces is a new feature in Server 2012 (and Windows 8) and it lets you combine disks and create virtual disks on them that are striped, mirrored, or have parity (think of it as software RAID).
We can create a new Storage Pool by right clicking on Failover Cluster Manager > Storage > Pools and select New Storage Pool.
Click Next, give the Pool a name …
… select the disks that will make up the pool (notice that the disks shown below are the iSCSI disk that are visible to both nodes; neither disk is actually on the local computer, they are both from a SAN box someplace (in this case the WIN-DATA01 & WIN-DATA02 servers from where we created these before) …
… and click Create.
Right click on the pool that was created and make virtual disks on that. These virtual disks are software RAID equivalents. (The pool is a placeholder for all your disks. The virtual disks are the logical entities you create out of this pool). Here’s the confirmation page of the pool I created:
Once the disk is created, be sure to not uncheck the “Create a volume when this wizard closes” check box. If you did uncheck, you’ll have to go to Server Manager > File and Storage Services > Volumes, click on TASKS and select New Volume. The virtual disk is just a disk, what we have to do now is create volumes on it.
Below is a screenshot of the volume I created. I chose ReFS for no particular reason, and assigned the full space to the volume. Also, the screenshot shows that I didn’t assign a drive letter. That’s incorrect. I did just that I forgot to do that when taking this screenshot. (Note that I assigned the drive letter R. This will be used later).
Via PowerShell:
|
1 2 3 4 5 6 |
PS> New-VirtualDisk -StoragePoolFriendlyName Pool1 -FriendlyName LUN-MIRROR -ResiliencySettingName Mirror -UseMaximumSize FriendlyName ResiliencySettingNa OperationalStatus HealthStatus IsManualAttach Size me ------------ ------------------- ----------------- ------------ -------------- ---- LUN-MIRROR Mirror OK Healthy True 116 GB |
As with the GUI, once the disk is created a cmdlet has to be run to create a volume on the disk. It’s probably the New-Volume cmdlet, but it’s throwing errors in my case and I am too tired to investigate further so I’ll skip it for now.
Add Roles
Finally lets add the iSCSI target server role.
Right click Failover Cluster Manager > Roles and select Configure Roles.
Click Next, select iSCSI Target Server, and click Next. This steps assumes the iSCSI Target Server role is installed on both nodes of the cluster. If not, install it via Server Manager or PowerShell.
Give the role (the virtual server that hosts the role) a name and IP address …
… select storage (the previously created volume; if you missed out on creating the volume go back and do it now), click Next, Next, and that’s it.
At this point it’s worth taking a step back to understand what we have done. What we did just now is create a virtual server (a role in the cluster actually) and assigned it some storage space. One might expect this storage to be the one that’s presented by the iSCSI server as a target, but no, that’s not the case. Think of this server and its storage as similar to the WIN-DATA01 and WIN-DATA02 servers that we dealt with initially. What did we do to set these as an iSCSI target? We created a target, created virtual iSCSI disks, and assigned mappings to them. That’s exactly what we have to do here too!
Ideally one should be able to use the GUI and do this, but Server Manager seems to have trouble communicating with the newly created WIN-DATA server. So I’ll use PowerShell instead.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 |
# Note that R is the drive letter I assigned above PS> New-IscsiVirtualDisk -ComputerName WIN-DATA -Path R:\WIN-DATA-LUN1.vhdx -SizeBytes 50GB ClusterGroupName : WIN-DATA ComputerName : WIN-DATA Description : DiskType : Dynamic HostVolumeId : {B5A5F526-89D0-4DC1-9659-35E3625CB1D5} LocalMountDeviceId : OriginalPath : ParentPath : Path : R:\WIN-DATA-LUN1.vhdx SerialNumber : 896D918D-D8B6-46E1-AB6E-13E2D7B9E6C5 Size : 53687091200 SnapshotIds : Status : NotConnected VirtualDiskIndex : 1555336877 PS> New-IscsiServerTarget -ClusterGroupName WIN-DATA -ComputerName WIN-DATA -TargetName LUN1 -InitiatorIds Iqn:iqn.1991-05.com.microsoft:win-data01.rakhesh.local,Iqn:iqn.1991-05.com.microsoft:win-data02.rakhesh .local ChapUserName : ClusterGroupName : WIN-DATA ComputerName : WIN-DATA Description : EnableChap : False EnableReverseChap : False EnforceIdleTimeoutDetection : True FirstBurstLength : 65536 IdleDuration : 00:00:02 InitiatorIds : {Iqn:iqn.1991-05.com.microsoft:win-data01.rakhesh.local, Iqn:iqn.1991-05.com.microsoft:win-data02.rakhesh.local} LastLogin : LunMappings : {} MaxBurstLength : 262144 MaxReceiveDataSegmentLength : 65536 ReceiveBufferCount : 10 ReverseChapUserName : Sessions : {} Status : NotConnected TargetIqn : iqn.1991-05.com.microsoft:win-cluster01-lun1-target TargetName : LUN1 PS> Add-IscsiVirtualDiskTargetMapping -ComputerName WIN-DATA -TargetName LUN1 -Path R:\WIN-DATA-LUN1.vhdx |
And that’s it! Now I can add this target back to the WIN-DATA01 & WIN-DATA02 servers if I want (as those are the Initiator IDs I specified) and whatever I write will be written back to their disks via this clustered iSCSI target. I am not sure if the mirroring will happen across both servers though, but this is all just for fun anyways and not a real life scenario.
Lastly …
Before I conclude here’s something worth checking out.
The WIN-DATA virtual server is currently on the WIN-DATA04 node. This means WIN-DATA04 is the one who is currently providing this role, WIN-DATA03 is on standby.
If I login to WIN-DATA04 and check its disks I will see the mirrored volume I created:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
PS> Get-Disk Number Friendly Name OperationalStatus Total Size Partition Style ------ ------------- ----------------- ---------- --------------- 0 VMware, VMware Virtual S SCSI Disk De... Online 60 GB MBR 1 VMware, VMware Virtual S SCSI Disk De... Online 60 GB MBR 6 Microsoft Storage Space Device Online 116 GB GPT PS> Get-Volume DriveLetter FileSystemLabel FileSystem DriveType HealthStatus SizeRemaining Size ----------- --------------- ---------- --------- ------------ ------------- ---- C NTFS Fixed Healthy 50.81 GB 60 GB E ISCSI NTFS Fixed Healthy 59.86 GB 60 GB R VOL-MIRROR ReFS Fixed Healthy 115.33 GB 115.94 GB A Removable Healthy 0 B 0 B D CD-ROM Healthy 0 B 0 B |
If I do the same on WIN-DATA03 I won’t see the volume.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 |
PS> Get-Disk Number Friendly Name OperationalStatus Total Size Partition Style ------ ------------- ----------------- ---------- --------------- 0 VMware, VMware Virtual S SCSI Disk De... Online 60 GB MBR 1 VMware, VMware Virtual S SCSI Disk De... Online 60 GB MBR PS> Get-Volume DriveLetter FileSystemLabel FileSystem DriveType HealthStatus SizeRemaining Size ----------- --------------- ---------- --------- ------------ ------------- ---- C NTFS Fixed Healthy 50.85 GB 60 GB E ISCSI NTFS Fixed Healthy 59.86 GB 60 GB A Removable Healthy 0 B 0 B D CD-ROM Healthy 0 B 0 B |
If I right click on the role in Failover Cluster Manager, select Move > Select Node, and select the new node as WIN-DATA03, then this becomes the new active node. Now if I check the volumes and disks of both servers the information will be the other way around. WIN-DATA03 will have the volume and disk, WIN-DATA04 won’t have anything!
This is how clustering ensures both servers don’t write to the shared storage simultaneously. Remember, the shared storage is just a block device. It doesn’t have any file locking nor is it aware of who is writing to it. So it’s up to the cluster to take care of all this.
Also …
Be sure to add WIN-CLUSTER01 and WIN-DATA to DNS with the correct IPs. If you don’t do that Server Manager and other tools won’t be able to resolve the name.
There’s more …
This post is just a tip of the iceberg. There’s so many more cool things you can do with iSCSI, Clustering, and Storage Spaces in Server 2012 so be sure to check these out elsewhere!