HPE Storage Users Group

Hi everybody, sorry in advance if my question may be obvious to some of you but I really can't figure out how to accomplish this.

We have a VVol that is currently Exported to two hosts (cluster setup). But now we need to detach the volume from only one of the two Host, without loosing connectivity between the other host and the volume.

When I click Unexport on the VVol, it seems that the only option I have is to unexport the VVol from both Host. I have searched a way to do it one host at a time but never found a way to do it.

I am missing something obvious?
Regards

Howdy. Was this Lun exported to each host separetely or to a host set?

If each host, and not a host set, goto hosts section and select the host, then in the sub-pane under the main one, view the VLUN templates, and delete the one for the Lun you want to remove.

If its exported to a host set, and it's the ONLY Lun / active VLUN on the host set, then you can remove the node from the host set.


If you have many luns, or a set of luns exported to the host set, you are stuck doing removing the Lun from both and re-adding it. However there was an option worth investigating with support.... You might be able to creat a new export template that will over ride the one do you can delete it. I have never tested that "override" checkbox so be sure to vet that idea through support first.

Richard Siemers wrote: If each host, and not a host set, goto hosts section and select the host, then in the sub-pane under the main one, view the VLUN templates, and delete the one for the Lun you want to remove.

Hi Richard, thanks for the quick answer. It worked fine.

In the other hand, I am not to sure if I like this part:

If you have many luns, or a set of luns exported to the host set, you are stuck doing removing the Lun from both and re-adding it.

In some cases, it might not be very practical. I hope HP will listen to customer and make this type of operations easier, more intuitive. I would consider involving support if needed, but I think it should be easier than that.

Regards
Nicolas

Practicality varies by situation for sure. Sorry for the short reply above, I was on my mobile phone, but it allowed a quick response! =)

In the old days, you would have to export every single lun to every single host... as you can imagine in a large ESX cluster thats ALOT of clicking.

So then they came up with autonomous groups by implementing Host Sets, and Volume Sets... and all the flexibility of choosing wether or not to use one, or both features. While the system will allow you to use a Host Set in combination with a Volume Set, I would not consider this a best/common practice and over kill for the caveats mentioned above.

I have settled with host sets for clusters, and not using volume sets. If its a cluster object, it exports to the host set, if its just for a single node of the cluster is exported to just the single node. I suppose in a extreme situation where we needed to remove 1 lun from 1 node that was a member of a set... we could leverage host level HBA driver LUN masking options.

I'm sure there is a time and place for volume sets as well, I'm thinking routine exports/unexports for snapshot refreshes etc. We haven't needed to go down that route yet.

Hi Richards, I agree with what you are saying. Both Volume sets and Host sets have their place and utility, that's for sure.

But if I compare the the IBM and EMC units we are also managing here, I would say that it is more a question of how they behave in the GUI that may need some adjustement, so they could become extremely powerful, robust in every situation, instead of being a tricky feature that could put you in a corner in some scenario.