HPE Storage Users Group

Hi everyone, I have a kind of complicated situation. We`re a hospital mostly utilized VMWare. I have my VCenter 5.1 (hosts are esx4 and esxi4.1) and another vendor in the hospital has their own vCenter 3.5 (hosts are esx3.5) Everything is on 3PAR 7400, both vCenters see 3PAR.
Here is the situation:

All data stores are exported to VV Set which exported to Host Set which has all the hosts from vCenter 3.5 and vCenter 5.1

We did like this coz we were in the migration process and everything needed to see everything.

Now they want to separate so vCenter 5.1 and vCenter 3.5 will not see other vCenter`s datastores.

What I need is to remove their hosts from my host set, create a host set for their hosts. Unexport their VVs from my hostset and export to their host set. Can I move a host from one host set to another host set without interrupting VVs exported to that host?

What do I need to do so I don`t screw up both vCenters? Thank you for any help.

Yikes, thats a pickle of a situation, and illustrates why I recommend against using both HOSTSETS and VVSETS in the same VLUN template (export).

Here is a potential method you can use to resolve your situation.

Create a NEW VV, and a new VVSET for vCenter 3.5
Export the VVSET to just the vCenter 3.5 hosts.
Create a new datastore in vCenter 3.5 for the new LUN.
Use VMWARE to migrate one of the vCenter 3.5 data stores over to the new LUN(S), thus freeing up the old DATASTORE/LUN.
Once the old LUN is empty, decommission the old datastore, remove it from the old VVSET.
At this point, if your thin provisioned, you might want to destroy and recreate the LUN, if its thick provisioned, you can just re-assign it to the new VVSET.
... wash rinse repeat until you have split out all your 3.5 VVs for that group into the new VVSET... then... remove your 3.5 hosts from the 4.x host group.

Thank you for answering Richard.
They have only handful of VVs so this time I`m not gonna use VV Set. I`ll just export to new Host Set I created for them.
We use everything Thin provisioned.
So it`s gonna be:

Create new VV -> Export to new Host Set
Shutdown and unregister VM from vCenter 5 -> Register VM on vCenter 3.5 ->
Bring the VM up -> Storage vmotion to new VLun.
Delete old datastore on vCenter 5 -> Unexport VV from old Host Set
Delete old VV from 3PAR

That`s sums it up, right?

BarbaroB wrote:Create new VV -> Export to new Host Set
Shutdown and unregister VM from vCenter 5 -> Register VM on vCenter 3.5 ->
Bring the VM up -> Storage vmotion to new VLun.
Delete old datastore on vCenter 5 -> Unexport VV from old Host Set
Delete old VV from 3PAR

That`s sums it up, right?

Create new VV -> Export to new Host Set
vCenter 3.5 should see the new LUN, create the new Datastore
vCenter 4.x should not see the new LUN/Datastore
Live Migrate 3.5 VMs to New Datastore using vCenter 3.5, see kb article

http://kb.vmware.com/selfservice/micros ... Id=1005544

(Alternatively, you could go the other way, and leave ESX 3.5 with the old VVSET/HOSTSET and use ESX4 to live migrate to new host set and data stores).

Decomission EMPTY datastore from vCenter5 and vCenter 3.5, then in the 3PAR IMC just remove the old/empty VV from old VVSET, it will automatically remove it from the hosts.

Do NOT right-click "Unexport" the VV. Since there is one template that exports VVSET to HOSTSET... if you to unexport just 1 host, or just one vv that is a member of that template, it will remove that 1 single template, which will remove all luns from all hosts in your situation.

Now I see why you don`t like to use both VV Sets and Host Sets in the same export. Thank you man, this helped a lot

Ok douchebags don`t wanna create new vluns and storage vmotion.
Can I export VV to 2 host sets at the same time and delete 1 like you explained here?

viewtopic.php?f=18&t=229&p=657&hilit=unexport#p657

BarbaroB wrote:Can I export VV to 2 host sets at the same time and delete 1 like you explained here?

viewtopic.php?f=18&t=229&p=657&hilit=unexport#p657

Yes you can export a LUN to 2 HostSets, however the gotcha with your environment is that the same hosts are members of both host sets. So Datastore1 might be LUN #1 on all your systems per your existing vlun template. Then you create a new HostSet, and add your ESX 3.5 hosts... your ESX 3.5 hosts are now in both host sets, and still have a LUN #1... then you go a create a new export of that Volume that contains Datastore1, the system knows that LUN #1 is already in use, so it increments that to LUN #2... now your ESX hosts see a LUN#1 as Datastore1 and now they also see a LUN#2 which also appears to have a datastore already on it...

I don't know what will happen, perhaps a VMware expert can add some wisdom here... but I have some theories:
1) the 3PAR system will realize that host already sees that VV and will not create the new export.
2) the 3PAR system doesn't care and creates the new export, but forces a new LUN# because the old one is already in use.
2a) ESX 3.5 sees a new LUN and does not recognize it as an already mounted datastore and possible corrupts the data.
2b) ESX multipath kicks in and adds the new LUN as additional paths the data store already mounted 2c) The situation causes a fold in the time space continuum forming a black hole, destroying everything.


Can you take an partial outage of just one of the 2 ESX environments to facilitate the split?

You could pre-stage a lot of the work:

Create the new HOSTSET for ESX 3.5, leave it EMPTY.
Export the proper ESX 3.5 luns for to the EMPTY ESX 3.5 host set. You can even go so far as to match up LUN#'s so that if it was LUN3 on the old layout, it will remain LUN3 on the new. Then wait for a maintenance window... shutdown the ESX 3.5 environment, remove the ESX 3.5 hosts from the OLD host set, add them to the new host set, power them on.

Can you take an partial outage of just one of the 2 ESX environments to facilitate the split?

You could pre-stage a lot of the work:

Create the new HOSTSET for ESX 3.5, leave it EMPTY.
Export the proper ESX 3.5 luns for to the EMPTY ESX 3.5 host set. You can even go so far as to match up LUN#'s so that if it was LUN3 on the old layout, it will remain LUN3 on the new. Then wait for a maintenance window... shutdown the ESX 3.5 environment, remove the ESX 3.5 hosts from the OLD host set, add them to the new host set, power them on.[/quote]


Hi Richard, thanks again for your precious help
Looks like we can take partial downtime. Here is what happened so far. We unmounted all data stores and detached all devices from my vCenter 5. For me to do 3PAR side, they will shut down all VMs and hosts. So I can follow your steps above right?

- Create the new HOSTSET for ESX 3.5, leave it EMPTY
- Export proper VVs to new host sest
- Shutdow VMs and hosts.
- Remove hosts from old hostset. Add them, to new host set.
- Power on everything.

So when you add a host to hostset which already has VVs exported. VVs get exported to that host automatically, right?

BarbaroB wrote:So when you add a host to hostset which already has VVs exported. VVs get exported to that host automatically, right?

Correct - Adding a host to an active hostset will get the member VVs exported automatically.

CASE CLOSED

We just finished the rearranging all VVs. Thanks for your help Richard