How to move a LUN from a SG with Fast VP to other SG ?

yes, host will lose access to the LUN if you move it from the SG (and SG is part of masking view). Moving the LUN from the FAST applied SG will clear the FAST Stats for the LUN.

regards,

Saurabh

Sreekanth,

Did you tried disassociating the SG from fastvp and then try adding the lun to new storage group.

I deleted one of my post as I assumed your doing some cluster operations but you have mentioned you want to move the lun from one SG to other then definetly it will loose access. Are you looking for host steps in doing that??

In case your sharing this lun to cluster then ->You can share lun across different SG's but if this existing host need to be added into cluster then you have to create a new cluster MV with cascaded IG and SG and then move lun, as one lun cant be masked with same wwpns using two MV's at one time. We once did by removing one HBA from single node to   --> cluster IG and then sharing the lun across both SG ,such host dont loose total access at one time to this luns. Do let us know what exactly your trying to do then we get full understanding of your question.

"A device cannot belong to more than one storage group in use by FAST" this is also one restriction when SG is associated with FASTvp so you need to plan that way.

Hi Mrinal,

Sorry for late response.

Yes, we want to share LUN/s of one SG to other SG/s in the same cluster. I believe you have solution to the scenario we have, could you please give me any example taking 3 servers where we first have 2 servers and later got 3 rd server to share few LUNs of first two servers. Also can you describe more on "cascaded IG and SG and then move lun" does this mean that parent and child IG concept has to be implemented ?

Waiting to hear from you.

Many Thanks,

Sreekanth Adari

Hi,

So if we make a cluster from initial deployement we make one cascaded IG and one shared SG and masking views seperate for shared and non shared. For example :-

A= 1st host in current cluster

B = 2nd host in cluster

C = new host need to bring in

IG_A = IG for host A , SG_A = non shared luns of host A , MV_A = masking view for non shared luns of A

IG_B = IG for host B , SG_B = non shared luns of host B ,  MV_B = masking for non shared luns for B

IG_cluster = Cascaded IG  with IG_A and IG_B in them for cluster where you want to share luns

SG_cluster = Storage group with luns that are shared across A and B .

MV_cluster = Masking view for the shared luns in cluster.

Now you want to add host 'C' into the above cluster and share all the shared luns then it becomes very easy.

Just add the IG_C to cascaded IG_A_B_cluster and that was all the shared luns will be shared across host C,

And if host C needs some local non shared luns you can create MV_C also.

But its different when you dont want all the shared luns to share across host C and only few of them from SG_cluster.

SG_C = New storage group for C.

Now add those luns to SG_C also and create a masking view MV_C. You need to make sure try to keep the lun number same when your adding the luns to the SG_C such that they are same in SG_cluster

Note: Here if this SG is part of FASTvp it will give u error to create the view.

If for the intial A & B hosts you dont have views done like we do for cluster and its a single MV and SG and one IG then you can create one for cluster and start moving those luns and hosts into it so in future also for adding any node to cluster it will become easy work.

Do let me know if this helped you .As still so many scenarios can be possible so I am just trying to guess your current setup of views.

Hi Mrinal,

Thanka a lot for the detailed explanation.

My scenario is the one what you specified in the Note. Existing SG's A & B are associated to FAST VP and is unable tos share one or few LUNs of A & B to new Host C.

In above when I mentioned we did similar work for my case it was moving a host online from one set of FA ports to other set of FA ports (mapping) without downtime.

Thanks a lot Mrinal, Your suggestions are helpful.

I have similar requirement here..

Server A has 1,2,3 Luns.

server B has 4,5,6 luns on it.

But here I want to present the 1,2,3 luns of Server A to server B as well. Both servers SG have Fast policy applied on it. Please help me out on how to proceed with this.

just like Mrinal suggested, if you want to keep it clean. Or create a brand new storage group, add LUNs 1,2,3 and then create a brand new masking view with this new storage group and server B initiator group. I think that should work but you are getting into very messy configuration.  Take the time (and associated downtime) to do it right. I have 3 masking views, masking view 1 is for LUNs presented to server A, masking view 2 is for LUNs presented to server B and masking view 3 is for shared LUNs.