How to calculate,how many storage units can be created (X) with (Y) no. of drives ?

[RahulG]

http://eval.symantec.com/flashdemos/products/netbackup/dedupe_calc2/

http://eval.symantec.com/flashdemos/products/netbackup_puredisk/calculator/

[Nicolai]

What is the point with this qustion ?

[nbuno]

Nicolai, it wont hurt knowing how many storage units we can create having some number of drives at our disposal beforehand...also,its more of an inquisitiveness :)

[Marianne]

One STU per media server per drive type per robot.

[nbuno]

Marriane,if you dont mind can you break it up with an example pls...

[Adonis_Manansal]

Hi nbuno,

First off, (Taken from NBU AdminGuide volume I) Storage Unit is a label that NetBackup associates with physical storage. The storage can identify a robot, a path to a volume, or a disk pool. A Storage units can be included as part of a storage unit group or a storage lifecycle policy.

Storage Unit types:

• Media Manager - points to a robot or a stand-alone drive
• NDMP - Points to an NDMP host (NDMP Option)
• Disk
•      Basic Disk - Points to a directory
•      Puredisk - points to a disk pool (NetBackup Deduplication Option and Puredisk Storage Option)
•      SnapVault - points to a SnapVault server (SnapVault option)
•      OpenStorage - Points to a disk pool (an intelligent appliance on a SAN) (OpenStorage Disk Option)
•      AdvanceDisk - Points to a disk pool (storage directly attached to a media server) (Flexible Disk Option)

Now, to elaborate what Marianne answered:

# of STU = 1 STU/Media Server/STU Type/per robot

[Nicolai]

Since there is no 1:1 relation between physical devices and storage units you can create so many storage units that you can confuse the admin before Netbackup.

That does not provide  a definite number - but try to keep a 1:1 ration as rule of thump. This does not always work - e.g if you do duplication where you may have two storage unit pointing to the tape tape devices but different "concurrent write drives".

[Marianne · Accepted solution]

As per Nicolai's excellent post, there is no 1:1 relationship between STUs and devices, merely device type (drive density) and location (robot number and media server).

So, some examples:

• 1 robot in environment with LTO4 (hcart) tape drives, 3 media servers attached to drives in this robot
  3 STUs:
  media1-hcart-robot-tld-0
  media2-hcart-robot-tld-0
  media3-hcart-robot-tld-0
   
• 1 robot in environment with LTO3 (hcart3) and LTO4 (hcart) tape drives, 3 media servers attached to both drive types in this robot:
  6 STUs:
  media1-hcart3-robot-tld-0
  media1-hcart-robot-tld-0
  media2-hcart3-robot-tld-0
  media2-hcart-robot-tld-0
  media3-hcart3-robot-tld-0
  media3-hcart-robot-tld-0
   
• 2 robots in environment, one with LTO3 tape drives and another with LTO4 tape drives, 1 media server attached to drives in robot 1 (TLD(0)),  1 media servers attached to drives in robot 2 (TLD(1)), 1 media servers attached to drives in both robots.
  4 STUs:
  media1-hcart3-robot-tld-0
  media2-hcart-robot-tld-1
  media3-hcart3-robot-tld-0
  media3-hcart-robot-tld-1