Introduction

A memo about Raid manager and LUN

reference

https://milestone-of-se.nesuke.com/sv-basic/architecture/disk-term/

Understand storage from connectivity

https://www.atmarkit.co.jp/ait/articles/0808/25/news120.html

What is volume

A volume is a disk area that can be formatted into a ** file system, such as "physical disk", "RAID group (virtual disk)", or "LUN", regardless of physical or logical. ** **

** RAID group is also volume, LUN is volume, LVM is volume, / dev / xxx is volume **

What is a logical drive (LUN)? Logical identification number

http://e-words.jp/w/LUN.html

RAID devices, storage servers, etc. are recognized as one device from the outside by bundling multiple physical storage devices (hard disks, SSDs, etc.) (Raid group, Raid array), but this is logically divided. By assigning and identifying each LUN, it becomes possible to manage it as different storage (the whole may be one LUN).

** A logically divided area from a RAID group, Raid array or storage pool **

Raid Group, Raid Array

Multiple drives in the server are bundled by the "RAID controller" in the server.
** When viewed from the OS, this RAID group is recognized as one disk (virtual disk) **

What is a storage pool?

** Contains one or more Raid groups **
Storage pools can be used depending on the storage product.
Combine multiple Raid groups into one volume **
Can be split from a storage pool into multiple logical drives (LUNs) and mapped to a server

What is a storage pool in KVM?

** Storage products can be used in the same way as storage pools **
You can register devices (volumes) such as / dev / xxx (Raid array or any volume looks good), combine them into one volume, and allocate storage space to the virtual machine from there.

About Raid group and LUN