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Netapp Head swap iSCSI configuration

I recently did a head swap between a FAS2050 and a FAS3210 without too much of a problem.  I used the root volume from the FAS2050 and everything came up fine with the exception of the iSCSI configuration.  All of the LUN's came up, but none of the mappings came up and I had to re-create it manually.  This was not a huge deal for this swap since it had a total of two connections, but the next two I do have somewhere in the area of about 20 mappings each.

Is there any way I can avoid having to re-do this all manually or did I miss something with the iSCSI setup when I did my first migration so that the information didn't copy over?  The same network address is being used, so I'm hoping that most of the initiators can just pick up on the setup.

Thanks.

Re: Netapp Head swap iSCSI configuration

Hi,

I'm assuming that with "mappings" you are referring to some part of the igroup and lun mapping configuration.  Was it just the lun maps?  What ONTap version?

The only migration problems that I have run onto are problems with the changing iscsi nodename with headswaps (you can set it in one of the priv modes, iirc) and that on certain upgrades, LUN serial numbers have changed.  Having a recent ASUP mail will save you in a lot of the unexpected situations.  Scripting known changes will save you time.

Good luck.

Re: Netapp Head swap iSCSI configuration

If you keep the same root volume after controller swap, all of the configuration of luns, igroups, lun mappings to igroups, ips and iscsi nodenames should move over with no issue.  Sometimes you have to modify /etc/rc and /etc/hosts if port names change (e0c to e4a after swap for example).

Did you do a complete head swap or did you use the existing root volume on disks that shipped with the new controller?

Re: Netapp Head swap iSCSI configuration

We went from a FAS2050 that had 5 shelves and added them to a FAS3210 that had two shelves with it that were pretty much blank.  We used the root volume from the FAS2050 and initialized it once it was connected to the new head and all of the configurations came with it with the exception of the iSCSI setup.  (Snapmirror, network, etc were all fine.)  

When I checked the LUN's it listed no mappings at all and had no initiators, igroups or anything listed.  I had to re-create them.

Re: Netapp Head swap iSCSI configuration

The version is 7.3.5.1.  I think I answered the rest of the questions in my other reply.

Re: Netapp Head swap iSCSI configuration

We used the root volume from the FAS2050 and initialized it once it was connected to the new head

What exactly do you mean under "initialized it"?

Re: Netapp Head swap iSCSI configuration

We onlined the aggregate by doing aggr online aggr0 and then vol options vol0 root and then rebooted.  I renamed the aggr and vol0 on the FAS3210 head before I shut everything down.  When it came back up, vol0 that was used on the 2050 was the one in use.

Re: Netapp Head swap iSCSI configuration

Where and how igroups and mappings are stored still remains a great secret, apparently protected NetApp above everything. But one thing for sure – when you online volume (which is implicitly done when you online aggregate) NetApp rescans storage for LUNs. If your LUNs were located on the same aggregate it could have happened that any igroup mapping was removed from LUNs (assuming they are stored somewhere with a LUN).

I really wish someone from NetApp would finally explain in simple words where igroups and mappings are stored.

In general, what you have done is the wrong way to do upgrade. You normally just connect old shelves to new head, re-assign disks and come up with exactly the same config as before. Then – if I have reasons to think newly delivered system has own root volume – I connect new shelves online and simply destroy new root volume/aggregate if it appears.

Re: Netapp Head swap iSCSI configuration

The new NetApp was up and runing for a week or so due to us having internal storage on the head and it needing to be snapmirrored off.  So it had it's own setup and everything. I created vol0 on a different aggr then where the snapmirror destinations were.  So after moving the shelves over, changing the disk assignments and then setting the vol0 from the old head as the main vol0, everything came up fine with the exception of the lun's.  I did it by using the directions I found at this place:

http://now.netapp.com/NOW/knowledge/docs/hardware/NetApp/cs_migration/FAS2xxx/FAS2040_internal_storage_to_FAS32xx_single-controller/GUID-55D5319A-2319...

Re: Netapp Head swap iSCSI configuration

I have run into this issue on almost every controller upgrade I've performed. I've talked to NetApp support & PS engineers, they've both told me they've never seen this happen. I'm trying to determine where this information is stored so I can back it up. The only way I've been able to save the config is doing a "igroup show" & "lun show -m" and then manually recreate the igroups & maps.

I always use the original root volume from the older controller.

The only thing I can think of is the time at which I online the "foreign" aggregate which resided on the older disks.

1. Cable all disk shelves

2. re-assign disks from old controller to new controller

3. Boot into ONTAP

4. Online the aggr, which onlines the volumes. At this point I see a bunch of messages similar to the one below:

Sat Mar 10 16:43:21 EST [netapp01a: lun.newLocation.offline:warning]: LUN /vol/data/lun3 has been taken offline to prevent map conflicts after a copy or move operation.

Do I need to online the aggr's in maintenance mode?