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How do we ensure LUN consistency when using Parent/Child storage groups?

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As an example, we'd like to build something like the following

Parent SG

Child SG1 = Lun 1,2,3

Child SG2 = Lun 4,5,6

I understand on the init group we must enable lun_consistency option. My question is moreso, what are the steps in order to ensure my luns are assigned according to the configuration we design?

I was looking in Procedure Generator and did not find what I was looking for.

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briand3
6 Indium

Re: How do we ensure LUN consistency when using Parent/Child storage groups?

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What I've done in the past is this:

1.  Create Child SG with one device in it.

2.  Create Parent SG with Child SG in it.

3.  Create view and specify the lun '-lun 0' etc.

4.  Go ahead and add in luns 2, 3.

5.  Create the second Child SG with device that you want fourth.  I'll explain this in a second.

6.  Add the second Child SG to the Parent SG.

7.  Add the devices and specify the LUN ID.

The reason that I only suggest putting only one device in there is due to the fact that if your desired device order doesn't run in sequence with Symmetrix device ids.

Enabling '-consistent_lun' when you create the initiator groups simply ensures that host lun presentation from each of the FA ports is the same for all FA ports in the port group.

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8 Krypton

Re: How do we ensure LUN consistency when using Parent/Child storage groups?

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Look in the Solutions Enabler Array Controls Guide in the Section on Auto Provisioning Groups. When you add devices to a storage group one of the options is to specify the LUN address.

8 Krypton

Re: How do we ensure LUN consistency when using Parent/Child storage groups?

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Hi hernan,

Do your six LUN present to same host through same FA port? If so, you can define the LUN ID during mapping operation using symcli command. Refer AranH posted Array Control Guide for the syntax.

8 Krypton

Re: How do we ensure LUN consistency when using Parent/Child storage groups?

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Checked the SE 7.6 Array Controls Guide and they do not specifically lay out the process, but after further review, it probably goes something like this:

1) create empty ParentSG

2) create ChildSG1 and include LUNs (aka devs ) 1, 2,3   - (knowing we can't assign LUN at stor group creation)

3) Add ChildSG1 as child of ParentSG

4) Create masking view using the ParentSG for storage group, adding "-lun 1,2,3" at end of command.

5) create ChildSG2 and include LUNs (aka devs ) 4,5,6

6) Add ChildSG2 to Parent SG, using "-lun 4,5,6" at end of command

I will need to test, but can anyone confirm these steps?

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briand3
6 Indium

Re: How do we ensure LUN consistency when using Parent/Child storage groups?

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What I've done in the past is this:

1.  Create Child SG with one device in it.

2.  Create Parent SG with Child SG in it.

3.  Create view and specify the lun '-lun 0' etc.

4.  Go ahead and add in luns 2, 3.

5.  Create the second Child SG with device that you want fourth.  I'll explain this in a second.

6.  Add the second Child SG to the Parent SG.

7.  Add the devices and specify the LUN ID.

The reason that I only suggest putting only one device in there is due to the fact that if your desired device order doesn't run in sequence with Symmetrix device ids.

Enabling '-consistent_lun' when you create the initiator groups simply ensures that host lun presentation from each of the FA ports is the same for all FA ports in the port group.

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