Allocate a LUN – carving

Hitachi designed the Device Manager so you can always carve a lun for whatever part of the resource tab you are into (and not only). The Create Volume task is available from a multitude of locations throughout the app. Carving is the operation that will take a slice out of a pool and allocate a unique identifier for that slice ready to be utilized in day to day operations. You can also get volumes from external locations using virtualization but we will be discussing that in the virtualization articles. This part focuses on the "day-to-day" carving operations from a regular pool (HDT or HDP)

You can lunch the wizard from different locations in device manager:

  • General Tasks - Create Volumes
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  • While in Resouces Tab, Actions Menu - Create Volumes
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  • While having pools selected, Click the button Create Volumes.
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If the wizard if opened from anywhere else other then the pools screen it will look like this and you will have to specify the following data.

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Specify the number of volumes, the volume capacity, the storage system and volume type. Based on the type select the appropriate pool, give it a name, select a name if need to and you are ready to go.

Number of volumes

  • specify how many volumes you want to carve

Volume capacity

  • can be specified in MB, GB, TB or block size.
  • block size is normally used if the volume will participate in a replication pair as a secondary volume (S-VOL)

Storage system

  • - Device Manager can manage multiple arrays at once, this field will dictate from what array the carving will be done.
  • - Based on this the volume type will be populated with different values depending on licensing and pool types on this storage system

Volume type

  • Dynamic Tiering - Specify that the volume will be a HDT volume
  • Dynamic Provisioning - Specify that the volume/s will be HDP volumes (also know as thin)
  • Basic Volumes - Specify that the volumes will be carved as Thick volumes

Pool

  • Specify the pool where the volume will be carved. Only pools of volume type will be displayed, so if you choose dynamic provision as a volume type you will not see in this part dynamic tiering pools
    addlun2

Internal/External

  • Internal - will use a pool that contains internal volumes
  • External - will use a pool that contains external volumes

You can also setup advanced options :

  • LABEL - you can assign a label to the luns so they are easier to manage (eg: db drive for sql server, log luns, backups luns, etc)
  • LDEV ID
    • Auto - next available LDEV ID is used
    • Manual - you can select an unsued ldev id in a specific CU

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