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Re: FC HBA disks - ioscan questions

 
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rventura
Frequent Advisor

FC HBA disks - ioscan questions

Hello,

 

I installed a card with 2 ports and each of these ports connect to a separate swtich.

 

I presented a 100GB disk to my RP3410 and i am a bit confused with the ioscan results. 

 

Running ioscan -fnC disk shows 4 device paths:

disk 9 0/3/1/0.1.17.0.0.1.2 sdisk CLAIMED DEVICE HP HSV300
/dev/dsk/c10t1d2 /dev/rdsk/c10t1d2
disk 7 0/3/1/0.1.18.0.0.1.2 sdisk CLAIMED DEVICE HP HSV300
/dev/dsk/c5t1d2 /dev/rdsk/c5t1d2
disk 8 0/3/1/1.1.17.0.0.1.2 sdisk CLAIMED DEVICE HP HSV300
/dev/dsk/c14t1d2 /dev/rdsk/c14t1d2
disk 6 0/3/1/1.1.18.0.0.1.2 sdisk CLAIMED DEVICE HP HSV300
/dev/dsk/c12t1d2 /dev/rdsk/c12t1d2

 

then if i run ioscan -kfNnC disk it shows the following:

disk 10 64000/0xfa00/0x4 esdisk CLAIMED DEVICE HP HSV300
/dev/disk/disk10 /dev/rdisk/disk10

 

What i am trying to understand is if i have 2 ports, shouldnt it only show 2 device paths instead of 4? Is it becase each san switch can go through either of the 2 EVA controllers resulting on 2 "paths" per port? If so then, because of the built-in multipath support in 11.31, all these 4 paths get me to the same disk /dev/disk/disk10, correct?

 

Thanks.

4 REPLIES 4
Patrick Wallek
Honored Contributor

Re: FC HBA disks - ioscan questions

>>Is it becase each san switch can go through either of the 2 EVA controllers resulting on 2 "paths" per port?

 

Correct.  

 

>>If so then, because of the built-in multipath support in 11.31, all these 4 paths get me to the same disk /dev/disk/disk10, correct?

 

You are correct.

Robert_Jewell
Honored Contributor
Solution

Re: FC HBA disks - ioscan questions

You can see the corelation between the standard and persistent paths using the command:

 

  # ioscan -m dsf

 

 

 

-Bob

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rventura
Frequent Advisor

Re: FC HBA disks - ioscan questions

Perfect.

This helps to visualize it a lot better.

Thanks to both of you.
Torsten.
Acclaimed Contributor

Re: FC HBA disks - ioscan questions

each EVA controller is connected to both SAN switches, so each HBA port can see both EVA controllers.

 

So you have 4 paths to the EVA.

 

# ioscan -m dsf

 

will show you,

 

# scsimgr get_info -D /dev/rdisk/disk10

 

and other scsimgr commands give you more details.

 

 


Hope this helps!
Regards
Torsten.

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