Author : Svetlana Voskoboinikova
Topic Name : SAN ブートのメリット
Publication Name : vSphere のストレージ
Product/Version : VMware vSphere/6.7
Question :
本ページ内では複数ESXiホストでSANブートを行う際、単一LUNの共有参照はNGとしています。 一方で以下のユーザーズガイド 12ページ真ん中では、次の表記があります。 SAN から起動する環境または Auto Deploy を使用する環境では、ESXi ホストごとに別個の LUN を割り当てる必要はありません。 https://docs.vmware.com/jp/VMware-vSphere/6.7/vsphere-esxi-67-installation-setup-guide.pdf 2つの質問は相反するように見えますが、どちらが正しいのでしょうか?
Question:
The Boot from SAN Benefits (docs.vmware.com...C47C21CBF0.html) topic states: "When you use boot from SAN with multiple ESXi hosts, each host must have its own boot LUN. If you configure multiple hosts to share the boot LUN, ESXi image corruption might occur."
While the ESXi Hardware Requirements (docs.vmware.com...54679202FC.html) topic has the following statement: "For environments that boot from a SAN or use Auto Deploy, you need not allocate a separate LUN for each ESXi host. You can co-locate the scratch regions for many ESXi hosts onto a single LUN. The number of hosts assigned to any single LUN should be weighed against the LUN size and the I/O behavior of the virtual machines."
Which statement is correct?
Answer:
Both statements are correct. The start of the second statement can be confusing when read out of context, but it is in the section discussing placement of /scratch storage. The boot files for an ESXi host should be on dedicated LUNs, however multiple hosts can share a LUN for storing /scratch in their own directories. That means each boot from SAN host will have two LUNs instead of a single LUN with boot and /scratch co-located.
The second statement can be clarified with "For environments that boot from a SAN or use Auto Deploy, you need not allocate a separate LUN for /scratch for each ESXi host. You can co-locate the scratch regions for many ESXi hosts onto a single LUN."
Question:
The Boot from SAN Benefits (docs.vmware.com...C47C21CBF0.html) topic states: "When you use boot from SAN with multiple ESXi hosts, each host must have its own boot LUN. If you configure multiple hosts to share the boot LUN, ESXi image corruption might occur."
While the ESXi Hardware Requirements (docs.vmware.com...54679202FC.html) topic has the following statement: "For environments that boot from a SAN or use Auto Deploy, you need not allocate a separate LUN for each ESXi host. You can co-locate the scratch regions for many ESXi hosts onto a single LUN. The number of hosts assigned to any single LUN should be weighed against the LUN size and the I/O behavior of the virtual machines."
Which statement is correct?
Answer:
Both statements are correct. The start of the second statement can be confusing when read out of context, but it is in the section discussing placement of /scratch storage. The boot files for an ESXi host should be on dedicated LUNs, however multiple hosts can share a LUN for storing /scratch in their own directories. That means each boot from SAN host will have two LUNs instead of a single LUN with boot and /scratch co-located.
The second statement can be clarified with "For environments that boot from a SAN or use Auto Deploy, you need not allocate a separate LUN for /scratch for each ESXi host. You can co-locate the scratch regions for many ESXi hosts onto a single LUN."