vmb01
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multpath question

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I have a FC storage with 2 SP active/passive and my servers have 2 HBA.

If I look at the default multipath policy on one of the datastore created on a LUN I see:

vnhba1:c0:t0:l0 standby

vnhba1:c0:t1:l0 standby

vnhba2:c0:t0:l0 active (I/O)

vnhba2:c0:t1:l0 active

The active (I/O) path is the path actually used for I/O and the standby paths are the paths that can be used for I/O if active paths fail.

What does it means the path active but without the '(I/O)' ?

And why this path is using the second SP on my active/passive storage?

I attach a screenshot.

AAny hel will be very appreciated.

Thanks in advance.

M

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LiamCurtis
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If I am not mistaken...If you look at the WWN's in the target, only one SP is being used, but each port on the SP is active....Your vmhba1 sees targets with 60 and 61 in the WWN (5th number from the right) which correspond to SPA. Likewise, your vmhba2 sees targets with 60 and 61 in WWN, which corresponds to SPB.

(edit-- Also...both of these 2 ports are listed as an 'Active' path to the single SP, yet only one has active I/O)

I found this link (amongst others) to be incredibly helpful when recently setting up ESX to my CX500:

You might want to think about changing your zoning so that each HBA can see each SP...that way if you lose a switch or an HBA, you will (in theory) not have a tresspass...It appears as though right now you have it set up so that each HBA only sees both ports on a single SP....

Just my two cents and open to debate...As a sanity check, be sure to do failover tests...

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AWo
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I think you use a Clariion, aren't you?

If only one SP is the active one the the other paths become active when the Clariion switches to the other SP. As you said, active/passive.


AWo

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LiamCurtis
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If I am not mistaken...If you look at the WWN's in the target, only one SP is being used, but each port on the SP is active....Your vmhba1 sees targets with 60 and 61 in the WWN (5th number from the right) which correspond to SPA. Likewise, your vmhba2 sees targets with 60 and 61 in WWN, which corresponds to SPB.

(edit-- Also...both of these 2 ports are listed as an 'Active' path to the single SP, yet only one has active I/O)

I found this link (amongst others) to be incredibly helpful when recently setting up ESX to my CX500:

You might want to think about changing your zoning so that each HBA can see each SP...that way if you lose a switch or an HBA, you will (in theory) not have a tresspass...It appears as though right now you have it set up so that each HBA only sees both ports on a single SP....

Just my two cents and open to debate...As a sanity check, be sure to do failover tests...

View solution in original post

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vmb01
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Enthusiast

Liam, i think you have reason .

So the T0 in the Runtime Name doesen't mean SP0 and T1 doesen't mean SP1

This is not the SP used to reach the LUN as I thought. Is it true ?

Thanks in advance

M

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LiamCurtis
Enthusiast
Enthusiast

Correct. The TO and T1 do NOT necessarily correspond to SPx0 and SPx1. The target WWN will tell you which SP and port you are actually connected to.