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Scale‑Out File Server.

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But first, we're going to do cluster witness.

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What is cluster witness?

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Well,

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we've talked a bit so far in this course about the concept of cluster quorum,

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which represents a majority vote count to keep the cluster online.

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Each node in your cluster is going to have a vote, and you

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need to think in advance about if you're starting with an

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even or odd number of nodes,

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what happens if a node becomes unavailable either through a

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planned maintenance event or an unplanned outage?

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This is where a witness can come in to provide a tie‑breaking vote.

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A witness is not a cluster node.

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Instead, it can be a disk, that is an accessible shared disk.

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That disk needs to be connectable from all cluster nodes.

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So Microsoft recommends that if you're going to do a disk witness,

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it should be for a single‑site cluster only. If you're

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doing a stretch cluster across sites,

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it's presumed that you can access SMB file shares between those

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sites, so file share witness is an option for multi‑site clusters.

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But honestly, in a hybrid cloud orientation,

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as long as your cluster nodes have internet connectivity,

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there's the cloud witness, which is a file share in an Azure storage account.

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Again, it's a convenient way to maintain a witness that's globally accessible, literally globally accessible.