SQLMCM Training – Day 10

Today Paul was speaking about Database Mirroring and Jonathan was talking about Failover Clustering – all in all a very intensive day J

Module 6: Database Mirroring

Module 7: Failover Clustering

  • Preferred owner configuration defines on which node a SQL Server can run
  • Cluster Validation Tests offline the shared cluster disks
    • You have to plan offline time
  • You need a current Cluster Validation Test Report for Microsoft Product Support Services to get help
    • Rerun Validation Tests, as soon as you add a new node to the cluster
  • Only the active nodes have to be licensed
    • The node with the most CPUs defines how many CPUs you have to license when you use a CPU based license
  • You need on odd numbe of votes to form a Quorum
  • Not enable Large Pages, when 2 instances can be run on one node
    • The whole buffer pool must be allocated during startup phase of SQL Server
  • SCSI-3 Persistent Reserveration must be enabled on the LUN level in the SAN
    • It’s normally not enabled by default
    • It’s needed for the shared disks in the cluster
  • TempDb is currently not supported on a local disk in a cluster
    • SQL Server Denali will support it
    • You can’t use currently SSDs als local disk for TempDb
  • Network Binding Order must be set with multiple NICs
  • MSDTC is only needed, when you need distributed transactions
    • MSDTC is installed as a cluster resource
      • MSDTC disk could be mounted on another cluster node
    • MSDTC should be in the same resource group als SQL Server
      • MSDTC can fail together with SQL Server
      • Otherwise MSDTC could get a bottleneck
  • You can have a separate MSDTC instance per SQL Server instance
  • Slipstreaming
  • Failback
    • Should be only configured, when the new failover node has less resources as the old one
    • Otherwise a failback occurs automatically as soon as the old node gets online
  • You need Disk Dependencies if you’re using Mount Points
  • Virtualization doesn’t provide you High Availability during Patching
  • Rolling Patches/Upgrades
    • Go to the SQL Server Instance Properties inside Cluster Manager (for each SQL Server Instance)
    • Advanced Policies Tab
    • Remove the Possible Owner who you are currently patching
    • The Instance is taken offline/online during Patching, therefore those steps are needed to be done
      • Patching node must be removed from the possible owners
    • After one instance is patched
      • Fail over to the patched instance, after allow it as a possible owner
      • Remove possible owner from the unpatched instance
      • Patch the unpatched instance

Thanks for reading

-Klaus

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