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How to duplicate Volumes / Nfs exports and LUNs config ?

Hi All,

We are about to add a new shelf to our NetApp Filer FAS3140. We need to duplicate all volumes from the original aggregates to this new aggregate :

Volumes, NFs  and LUNs config.

Is there a way to dump the config of the current aggregates, change volumes, NFS and LUNs names and get all those being created into the new aggregate ?

[ I had a look and config dump but I am not too sure whether it does exactly what we want ..]

Thanks !


Sebastien

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

If the new shelf is the same number and size of drives as the existing shelf, your best bet would be to mirror the aggregates.  This requires a syncmirror licence - but if you've just paid for the new shelf, chances are you'll be able to get a temp key.  Mirroring the aggregates is the simplest means - there is no downtime, and because nothing changes at the volume level, all the volume config (luns, masking, shares, etc.) stay the same.

If this isn't an option, then there is not really a one-stop config dump available.  The NFS share config is all in /etc/exports.  The CIFS share config is split between /etc/cifs_share.cfg and /etc/registry.  I've not seen the lun config in a file anywhere.  There are a couple of options for migrating data (vol copy, ndmpcopy, snapmirror, client side copy) - but they all incur varying levels of downtime, and require a mostly manual reconfig of shares and mapping.

Does that help?

Bill

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

Thanks Bill,

It does help. I should have mention that the new shelf will be added in a different NetApp filer from which we want to duplicate the configuration. So mirror thing is defintively not an option.

I guess we will have to go the manual way then.

Thanks for your help.

Seb

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

Sebastien,

What is the end goal? Have you looked at creating the new aggreate on the target filer and then using SnapMirror to mirror all the volumes over?

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

Paul,

The goal is to prepare our new aggregate that will be used by our DRP platform.

I had a quick look at SnapMirror and it does look great to do what we want.

Is it possible to use it only to initiate the environnement then stop it?  (our DRP process will be synced via another mechanism)

Also my understanding is that, after a SnapMirror, LUN will need to be manually re-mapped, do you know of other things to be done manually at the LUN level ?

Thanks for your help.

Seb

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

OK, that makes sense but one of the things that you need to take into consideration is that SnapMirror is a block level copy so it will send all blocks and then send only those blocks that have change.  Files are made up of one or more blocks so your DRP process is most likely a file level replication so if any block changes in a file, it will have to send the whole file again. Not a major problem if there isn't a lot of change rate but something you need to be aware of.

So you can SnapMirror to set up the inital replication and then have a schedule where changes are sent but at some point you will have to break the SnapMirror relationship and start your DRP process.  I'm not sure what DRP product you are looking at but my recommendation is to use one that integrates with SnapMirror (such as SRM for VMWare, etc.) as SnapMirror will be the best option for replicating data between NetApp controllers as it will only send the changed blocks.

As for LUNs on the target, you will need to zone your hosts to the storage controller (if FCP) or set up iSCSI.  Then you will need to create iGroups with the FCP or iSCSI initiators and then map the LUNs to the appropriate iGroups.

le me know if you have more questions

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

Thanks again Paul!

Yes our DRP process is roughly a big rsync... I would personnaly prefer to use SnapMirror to do this as it is optimized as you indicated it, and hope I could push this

I ve couple of concerns though:

- Even though I understand we can set a specific time for replication updates, I am wondering if the load might be noticeable on the source system ?

- Volumes on our source system are set with very low space for snapshot. Could this impact the SnapMirror process ? Or Snapshot created during SnapMirror are different from the Volumes snapshots ?

Thanks again.


Seb

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

Yeah, good luck with THAT :-)  I understand the difficulty.

- Yes there is some load on the controllers but SnapMirror is a low impact background process and unless you are syncing hourly and have a high change rate, there isn't a noticible impact

- SnapMirror uses a volume snap shot to track what blocks need to be synced during the next update so the disk space required for these snaps depends on the following:

1) The block change rate on the volume

2) How often you are syncing to the target.

The baseline snap for SnapMirror is updated once the sync takes place and the old baseline is released.

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

- Yes there is some load on the controllers but SnapMirror is a low impact background process and unless you are syncing hourly and have a high change rate, there isn't a noticible impact

I would argue with that - the truth is, your mileage may vary! It is better to be careful with running SnapMirror on a heavy loaded system during peak hours.

Updates can be easy scheduled outside of business hours, but doing the baseline is trickier - unless you can fit it in one night (or weekend, or whatever maintenance windows you have available). If we are talking loads of data for baseline, with initial transfer spanning multiple days, then throttling / switching off SnapMirror during peak business hours is strongly recommended (either manually, or via script).

Regards,
Radek

Re: How to duplicate Volumes / Nfs exports and LUNs config ?

Good point Radek.  I was referring to the scheduled updates not the initial sync. 

YMMV is an excellent way to express it. If the system is running at high utilization (systat -m 1 to see what each CPU is reporting) then scheduling the intial sync after hours and/or throttling the transfer rate (this isn't the greatest way of limiting resource utilization but it's the only one available) is a way to limiting the affect.  TR-3346 can give more detail on throttle.  

Also there are limits on the number of SnapMirror sessions that can be active at the same time. If I recall correctly a 3140 is limited to 16?