Virtual Datastore vs. LUN, and objects in general

I am configuring alerts for my cloud environment, and I've come across the preconfigured alerts for LUN space and Virtual Datastore space, and I'd like to understand the difference between these two objects. More generally, is there a reference that I can refer to for a description of all objects than can be alerted on?

Thanks,

RCS

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Accepted answers

jbiggley

Virtual Datastores are a concept of your virtualization environment.

A datastore is (as far as I know) a VMware term. Specifically, it references a block of storage that is formated with the VMFS file system and presented to one or more VMware hosts.

A LUN is a construct of your shared storage environment. A LUN (or Logical Unit Number) is a block of storage that is represented by a unique SCSI ID (or LUN ID!). This block of storage can be from a single disk (ie a single, local disk on a server), a JBOD or an array of disks in which the actual residency of your data is spread across multiple disks.

The datastore is made up of one of more LUNs. If more than a single LUN, the datastore connects the various LUNs into a contiguous block of storage for your VMware environment.

Soooo -- the alerting engine is asking whether you want to report on metrics gathered from your storage subsystems (LUNs) or your virtualized storage environment (datastores). They are sometimes very similar (a single disk LUN is a single datastore on an ESX host) and sometimes are very different. (Three LUNs from the same storage frame will be comprised of multiple physical disks but appear as a single datastore to the ESX host.)

You need to ask yourself whether you want to know how VMware sees the storage (one big block formatted with VMFS) or if you want to know how your shared storage environment sees it (as LUNs)

Is this what you were looking for?

All comments

mrs.alterego

rubincompserv‌ - I moved this to Storage Resource Monitor forum. Is this the product you are referencing regarding your alert questions? If not, let me know and I can move this to a more appropriate forum for you. I just want to make sure you are getting responses from those using the product in question. :-)

rubincompserv

To be perfectly honest, I'm really not certain. I know that I'm using Orion. When I configure my alerts, I have an option to alert on Node, Interface, etc., and that list also includes LUN and Virtual Datastore. I'll be glad to provide more information, just tell me what I'm missing.