HPE Storage Users Group

I have a VV set that is exported to many different hosts in a cluster. I'd like to unexport the VV's from one of those hosts, but apparently, it can't be done from the VV Set itself.

First off, when I right-click on the VV Set, "unexport" is grayed out.

This is okay, because I recall in the past, if I tried to unexport a VVset, it would not let me specify a host, and would instead, unexport it from any hosts of which it was a part.

What is the ideal way to remove a host from a VV Set? I'd think that we could just go to the host and unexport the VLUN template for that VV from the host directly, but calling HP they recommended unexporting the VV set from all the hosts and then exporting back to just those that need it. That is incredibly painful.

There has to be a better way...if not, could someone help explain why that is not the case?

Thank you.

We had some similar issues. The way 3par handles exporting VV Sets is horrible. We had to export all the individual LUNs to specific Host Sets. If you exported the VV Set itself then the UnExport should be available, are you sure you did not just export the individual VVs?

In the IMC in the left click Virtual Volume Sets, make sure in the main panel the Exported To volume is shown, if you see your VV Set and nothing is in the Exported To then you did not export the set, you exported the individual volumes. Also while the VV Set is highlighted in the lower pane you will see in the VLUNs tab both the VLUN Templates and the Active VLUNs. Be very careful deleting the VLUN Template as all the VVs exported via the set will be unexported.

In order to unexport a VV from a particular host try the cli:
removevlun -h
removevlun <VV> <LUN id> <host>
removevlun set:<VVSet> <LUN id> set:<hostset>

kluken wrote:We had some similar issues. The way 3par handles exporting VV Sets is horrible. We had to export all the individual LUNs to specific Host Sets. If you exported the VV Set itself then the UnExport should be available, are you sure you did not just export the individual VVs?

Looking at the virtual volumes tap on the host shows most of the VVs are there in a set, but a handful of direct exports exist, too.

kluken wrote:In the IMC in the left click Virtual Volume Sets, make sure in the main panel the Exported To volume is shown, if you see your VV Set and nothing is in the Exported To then you did not export the set, you exported the individual volumes. Also while the VV Set is highlighted in the lower pane you will see in the VLUNs tab both the VLUN Templates and the Active VLUNs. Be very careful deleting the VLUN Template as all the VVs exported via the set will be unexported.

The VV set doesn't show anything under the exported to section. Is it possible that these were exported directly to the host and then brought into a VVset?

As for the VLUN templates, isn't that created to link the VV to the VLUNs for a host? Wouldn't that make a template specific to a particular host, therefore manipulating a VLUN template for a host should only impact that host?

beltower wrote:In order to unexport a VV from a particular host try the cli:
removevlun -h
removevlun <VV> <LUN id> <host>
removevlun set:<VVSet> <LUN id> set:<hostset>

I appreciate the response. I'm not as familiar with 3PAR CLI as I would like, but my current concern here is less about the commands to do what I want, and what the impact of running those commands will have for all systems associated with these VVs/VVSets. This is mainly because HP is telling me that if I run those commands to remove a host from a VVset it will have undesirable effects for the other hosts associated with that VVset.

This doesn't make sense to me, but apparently, I have a bit to learn about the function and ties between the VVs, VVSets, VLUN Templates and Active VLUNS.

When you "export" a VV(set) to a host(set), what is really happening is a VLUN template is created. So the concept of "unexport" is dangerous because its misleading as it is really deleting a VLUN template.

If your VVSET was exported to each cluster node, 1 at a time, then you should be able to see several VLUN templates, find the one for the host you want to nuke, and delete that 1 VLUN template in the IMC.

I think it is possible to export a VVSET to several hosts at once, under one VLUN template, which would paint you into the corner I think you are describing. Double check your VLUN templates to see if its 1 per host, or one big VLUN.

Richard Siemers wrote:When you "export" a VV(set) to a host(set), what is really happening is a VLUN template is created. So the concept of "unexport" is dangerous because its misleading as it is really deleting a VLUN template.

If your VVSET was exported to each cluster node, 1 at a time, then you should be able to see several VLUN templates, find the one for the host you want to nuke, and delete that 1 VLUN template in the IMC.

I think it is possible to export a VVSET to several hosts at once, under one VLUN template, which would paint you into the corner I think you are describing. Double check your VLUN templates to see if its 1 per host, or one big VLUN.

Looking at the VVs in our VVsets, I see that a VLUN template has been created for each host that it is exported to. So, manipulating a VLUN template and the associated active VLUNs on a host should not impact the underlying VV for any other hosts, right?

I have noticed that VVs and VVsets exported to a Host Set don't appear to have individual VLUN templates per host. But they do have Active VLUNs on that host, which if I purged those for the host in question I should be okay. Of course in the VVset situation, ideally I'd just edit the VVset and remove the VV.

In the end, though, if export is to create a VLUN template and active VLUNs, then an unexport is effectively removing of the active VLUNs and, but not always, the VLUN template, depending on how the VV or VVset was exported to the host.

How common is it for people to manipulate VLUN templates and Active VLUNs directly? It doesn't seem like that big of a deal, as long as you connect the dots of what you are doing, which you'd do anyway before messing with exports.

It is good to hear that you have individual TEMPLATES that assign the VV SET to a single host, and not a HOST SET.

"Active VLUNs" automatically appear and disappear when hosts that match the template are online or offline. The Template will define which LUNs should appear to which hosts at what LUN#. Deleting a template will remove connectivity between VV(s) and a host(s), and not delete other templates or the VVs themselves.

Here is a good safety check you can use to be sure.
Power off the server you wish to decommission, or at least remove its SAN connectivity however you prefer (unzoning, unplug host's HBAs, put the host's switch ports offline, etc). Look at the list of VLUN templates, you should see the last column indicating how many active VLUNs each template has. The template for your decom host should show 0, and your active servers should show many. When you are ready right click the template you need to remove and unexport. The next window will show you a list of templates AND active VLUNs that will be removed. There should be no active VLUNs in the list if the template is inactive and not being used.

Hope this helps!