HPE Storage Users Group

Any harm exporting a LUN to a host and a host set? It seems most (all?) of our LUNs have been exported to both. However, in the VV view, there is only one Active LUN with it's LUN number.

But in the VLUN template view, I see the LUN exported to the host as well as to a host set, each with a different LUN #. And the user of the storage says he sees both depending on which path he looks at.

Should we remove the host set mappings or the direct host mapping? Why are these used and are they typically used without the use of a direct volume to host export?

I believe since this is a group of Tiered hosts, they have been mapped to all at once.

Hi Mohuddle,

If you can see 2 different LUN IDs in the template then you should be having 2 active LUNs with different LUN IDs. Please chekc again.

This Dual LUN ID issue might result in Data correction, so it always better to get rid off these 2 different LUN IDs and map with unique single ID.

The same issue occurs if you export single VV using individually and using Volume Set.

Hope this information is useful.

Regards,
KK

Just finished testing with VM admin. I UN-exported the LUN 18 he felt was not the correct one. I'm down to only one LUN ID, 23, for this LUN and it still shows it in my Tier2 host set.

All the VM admin saw were some hosts complaining about redundancy ( he said he would see LUN 23 down one path and LUN 18 down another path ), he has rescanned. No storage errors given.

Everything looks as I would expect on the 3PAR side...one LUN exported to a host set with a single LUN ID, 23.

I'm wondering if someone on my team exported to a host set and added it to a vv set? Would that do a double-export?

What you could do is create a new Volume set and a new Host set , and then just put one and one host in maintenance mode / power them off in order to fix the issue.

Hi Mohudle,

There are 2 ways dual LUN ID can be generated. (We tested in our environment)

1. Export a LUN individually to a host, and then add that LUN to VV set which is already exported to that host.

EX : LUN : Vtest1, Host : Htest1, VVset : VV_test1, Host Set HHtest1
Export Vtest1 individually to Htest1 -- LUN ID 5 (assume)
Export VVtest1 to Htest1
Move the Vtest1 to VVset VVtest1 -- LUN ID 6 (assume)

2. Export a LUN individually to a host XYZ and again export it to a host set where XYZ is member of the host set.
EX : Export Vtest1 to host Htest1 -- LUN ID 10
Move Htest1 to hostset HHtest1
Export Vtest1 to hostset HHtest1 -- LUN ID 11

Hope this information is useful.

Regards,
KK

Thanks a ton, kk2491, appreciate the feedback.