Cluster Heartbeats Node health monitoring CSV I/O Built-in resiliency for storage volume access Intra-Cluster Synchronization Replicated state across nodes

You there? Yes

Private Network Cluster Network 1 Private Network Cluster Network 1 Public Network Cluster Network 2 Public Network Cluster Network 2

Private Network Cluster Network 1 Private Network Cluster Network 1 Public Network Cluster Network 2 Public Network Cluster Network 2 Configuration Change

Lightweight and infrequent Latency in network would cause Metadata I/O to be slow performance Bandwidth not as important, but Quality of Service is… Metadata Significant bandwidth usage All I/O forwarded via SMB over the network Insufficient bandwidth may cause other important I/O to not go through Bandwidth is very important, as is Quality of Service… Failure Scenarios / Asymmetric Storage Connectivity

More deployment options with Windows Server 2012 for converged networking

Isolated network for the host partition Increased security isolation (could use VLAN’s to isolate from Client network) Host Management Public network for client access to VMs Virtual Machines Short duration heavy burst traffic Live Migration Intra-cluster communication is lightweight, but sensitive to latency Metadata updates are infrequent and light, but failure conditions could be heavy Intra-cluster communication / CSV Dedicated storage network Disable for cluster use iSCSI Key Takeaway: It is really about providing quality of service guarantees!!

Required? No – It is not required to have 2 separate networks Clustering does support a converged networking model Validation will generate a Warning to alert you of a potential single point of failure Validation is not NIC Teaming aware Recommended? Yes – It is recommended to have redundant network communication between nodes Sort of… let’s talk about what really matters and converged networking (next slide)

Resiliency

Same Subnet NIC 2 Same Subnet NIC 2 Cluster Network 1 NIC 2 Ignored By Cluster NIC 2 Ignored By Cluster Same Subnet NIC 1 Same Subnet NIC 1

NameValueDescription Disabled for Cluster Communication 0No cluster communication of any kind sent over this network Enabled for Cluster Communication only 1Internal cluster communication and CSV traffic can be sent over this network Enabled for client and cluster communication 3Cluster IP Address resources can be created on this network for clients to connect to. Internal and CSV traffic can be sent over this network

CSV Streaming I/O Across Multiple Networks X X

Highest Availability Tolerance of Transient Failures

Increasing heartbeat thresholds does not fix network problems, it only masks them! PropertyDefaultMaximumDescription SameSubnetDelay1 second2 secondsFrequency heartbeats are sent SameSubnetThreshold5 heartbeats120 heartbeatsMissed heartbeats before an interface is considered down CrossSubnetDelay1 second4 secondsFrequency heartbeats are sent to nodes on dissimilar subnets CrossSubnetThreshold5 heartbeats120 heartbeatsMissed heartbeats before an interface is considered down to nodes on dissimilar subnets

Cluster PropertyDefaultHyper-V Default SameSubnetThreshold510 CrossSubnetThreshold520

If enabled for iSCSI Software Initiator New Windows Server 2012 logic Disabled for Cluster Communication If no default gateway is present Enabled for Cluster Communication only If a default gateway is present Enabled for client and cluster communication

Prioritization Recommendation: Configure on all cluster deployments Heartbeats and Intra-cluster communication are sensitive to latency and configuring a QoS Priority Flow Control policy will ensure they are sent first Bandwidth Allocation Recommendation: Configure on CSV deployments CSV may send large amounts of data, need to ensure it has sufficient bandwidth Relative Minimum Bandwidth SMB policy recommended

Site A Site B

Do not attempt to find cross subnet routes if local routes are found Always attempt to find routes that cross subnets Disable the cluster service from attempting to discover cross subnet routes after node successfully joins

Site A Site B ValueDescription 0Clear Text 1Signed (default) 2Encrypted Disclaimer: Incurs some performance overhead

OR Network Name Resource IP Address Resource A IP Address Resource B

DNS Server 1 DNS Server 2 DNS Replication Record Created Record Updated Site A Site B Record Updated Record Obtained

DNS Server 1 VM = Site ASite B

DNS Server 1 DNS Server 2 FS = Site ASite B VLAN

DNS Server 1 DNS Server 2 VM = Site ASite B

PropertyDescription ResourceDataResource Internal Use (read only) StatusNetBIOSStatus (error) code for NetBIOS – 0 means no error (read only) StatusDNSStatus (error) code for DNS – 0 means no error (read only) StatusKerberosStatus (error) code for Kerberos – 0 means no error (read only) CreatingDCDomain controller upon which this netname’s AD object was initially created (read only) LastDNSUpdateTimeTime at which DNS was last updated (read only) ObjectGUID(read only) NameThe name published in NetBIOS and SAM account name in AD DnsNameThe name published in DNS RemapPipeNamesLegacy setting for SMB HostRecordTTLTTL in seconds of the DNS record, this controls how long caches will retain the record RegisterAllProvidersIP0 (false), 1 (true) – when enabled all IP addresses this netname depends on will be published to DNS no matter what their provider state is PublishPTRRecords0 (false), 1 (true) – Create reverse DNS records TimerCallbackAdditionalThresholdUnused

PropertyDescription LeaseObtainedTimeTime when DHCP lease was acquired (Read only) LeaseExpiresTimeTime when DHCP lease runs out (Read only) DhcpServerThe DHCP server that issued the lease (Read only) DhcpAddressAddress assigned by DHCP (Read only) DhcpSubnetMaskSubnet mask assigned by (Read only) NetworkThe network this IP address is on (such as “Cluster Network 2”) AddressThe IP Address assigned to this IP resource SubnetMaskSubnet mask EnableNetBIOS0 (false), 1 (true) - Controls whether this address is published by netbios OverrideAddressMatchThis setting is unused EnableDhcp0 (false), 1 (true) – determines whether this IP Address resource obtains its address via DHCP

SMB Client traffic Streaming I/O Across Multiple Networks X X \\server1\share1 Client