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Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

I was going through some of the docs from now website related to vfiler migration and got some queries on the same.

*     Is it possible to move a single volume from a vfiler in one controller to its partner controller vfiler. If yes how do we do it?

*     After vfiler migration complete is done the source vfiler unit will be destroyed, but the data remains. How do we remove the data? What are the things that one needs to do after vfiler migration?

*     snapmover changes the software based ownership of the aggregate hosting the vfiler. What if the aggregate also hosts some other volumes that needs to remain in the same controller?

*      One more on snapmove. Let us consider a scenario where we have a small aggregate with 6 disks assigned to it. 5 disk shelves assigned to each controller. During vfiler migration 5 extra disks from any of the 5 disk shelves will be assigned to the second controller. Is it an ideal situation? what would be the pros and cons?

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

I was going through some of the docs from now website related to vfiler migration and got some queries on the same.


*     Is it possible to move a single volume from a vfiler in one controller to its partner controller vfiler. If yes how do we do it?

yes, but not without downtime to my knowledge. In case you are ok with downtime you need to:

- remove the volume out of the vfiler     <vfiler remove>
- mirror the volume to new controller
- add the volume to new vfiler on new controller <vfiler add>

However if your purpose is to move the storage from a vfiler to a new vfiler on a new controller then there is a better way.
vfiler migrate.

*     After vfiler migration complete is done the source vfiler unit will be destroyed, but the data remains. How do we remove the data? What are the things that one needs to do after vfiler migration?

<vfiler remove> command will take the storage out of the vfiler and hand it back to vfiler0, aka the physical vfiler.

*     snapmover changes the software based ownership of the aggregate hosting the vfiler. What if the aggregate also hosts some other volumes that needs to remain in the same controller?

There is no mention in the doc. that disk ownership is impacted aggr wide. from what I have read it will only affect file systems in the vfiler at the time of migration.
NOTE: I have not tried this myself. 

*      One more on snapmove. Let us consider a scenario where we have a small aggregate with 6 disks assigned to it. 5 disk shelves assigned to each controller. During vfiler migration 5 extra disks from any of the 5 disk shelves will be assigned to the second controller. Is it an ideal situation? what would be the pros and cons?

I don’t believe this changes disk assignment, it should just recreate the volumes granted there is available space.

hopefully someone other will be able to help as well in case im wrong.

Eric

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

*     Is it possible to move a single volume from a vfiler in one  controller to its partner controller vfiler. If yes how do we do it?

Like Eric said... use mirror or another method to copy the volume then add to the partner vfiler.  All volumes/qtrees owned by the vFiler must be on the same controller and cannot span controllers.

*      After vfiler migration complete is done the source vfiler unit will be  destroyed, but the data remains. How do we remove the data? What are the  things that one needs to do after vfiler migration?

vfiler migrate stops the source vfiler, does a final mirror update, then activates the target vfiler. The cleanup work is to eventually destroy the volumes on the source and also delete the mirror snapshots on the target.  You also need to change the volume options "vol options volname fs_size_fixed off" on each volume on the target.  vfiler migrate does not change this, so any increase in vol size on the target won't be available until this option is changed on every volume in the migrated vfiler.  Note: the Data Motion feature (with ontap 7.3.3/7.3.4 and opsmgr/protmgr/provmgr 4.0) handles this by automating fs_size_fixed and also guarantees a 120 second migrate...but there are several restrictions including not being able to migrate between controllers in the same cluster.

*      snapmover changes the software based ownership of the aggregate hosting  the vfiler. What if the aggregate also hosts some other volumes that  needs to remain in the same controller?

The vfiler needs to own ALL volumes in the aggregate or snapmover (aka "vfiler migrate -m nocopy") will fail.  Since the aggregate needs to be reassigned if there are any foreign volumes not owned by the vfiler, then you cannot use snapmover. If you plan on using snamover, dedicate aggregate(s) to the vfiler.

*       One more on snapmove. Let us consider a scenario where we have a small  aggregate with 6 disks assigned to it. 5 disk shelves assigned to each  controller. During vfiler migration 5 extra disks from any of the 5 disk  shelves will be assigned to the second controller. Is it an ideal  situation? what would be the pros and cons?

Assymetric assignment of disks is not uncommon.  As long as you have enough spindles for performance for that aggregate, it is no issue... the best answer is "it depends"... If each controller is not overloaded and each aggregate is not overloaded it is not an issue.  Sometimes customers (with budget and good performance metrics) size a system so that they keep workloads (cpu, memory, disk, network) under 50% per controller so that a failover event doesn't cause degradation.

If you are at the Insight conference, please attend the MultiStore hands-on labs (shameless plug ) .  Roger Weeks and I are teaching again this year and I have updated labs and a 7.3.4 simulator we are distributing with the training on everything MultiStore...unfortunately no snapmover (can't do in the sim) but the command and requirements are covered in the class.  We have a basic, advanced and virtual environment presentation at the conference.

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

Scott,

Thanks for making things clearer. I was not aware a snapmover was aggregate wide and the impact/precautions this implies.

Cheers,

Eric

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

Thanks for your replies. Thread closed. :-)

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

You could use Netapp DataMotion:

http://www.youtube.com/watch?v=nMg3K4RocQI

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

Datamotion for vFilers does not work between cluster pairs unfortunately...it is on my wish list but not supported and won't pass the data motion pre-checks.  So we can only vfiler migrate between a cluster pair without the guaranteed 120 second failover, but in most cases we can keep the mirrors up to date enough where the migrate finishes in time (but plan for downtime).  WIth future ONTAP versions, we should see less data motion restrictions (faster to slower disks, bigger to smaller nvram, etc.  but no guarantee until we see it in the release notes of a new version ).

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

Do you have a link to the Data Motion TR or technical documentation? I can't seem to locate it. I wanted to look over the requirements and limitations

Thanks

Re: Move volume from controller 1 vfiler to controller2 vfiler in active/active configuration

TR3814 - Data Motion Best Practices  https://fieldportal.netapp.com/ci_getfile.asp?method=1&uid=5882&docid=23977    Section 7.1 on page 16 gives supported configurations and also 7.2 has more information.  A really good paper on Data Motion.