expanding a replicated concat device

Hi,

To add additional members to an existing concatenated metadevice, use the following

form:

add dev SymDevName[:SymDevName] to meta SymDevName;

Example: To add Symmetrix devices 0013 and 0014 to concatenated meta 0010, enter:

add dev 0013:0014 to meta 0010;

Note: Adding to concatenated metadevices preserves the metadevice data, but makes the new

members’s original data inaccessible.

Doc attached for reference.

Regards

Arpit Roy

Thanks Sun_deep541, Here are my answers:

1) Yes but no need to suspend the whole group (if the rdf group has more than device). You can suspend the RDF pair only. If this is sync replication then this should work with no issue, If this is "async" replication then you can suspend with -cons_exempt switch  then delete the pair.

2) Remove the device from the DG prior to deleting the pair because if the DG type is RDF1 or RDF2 and the device was there after deleting the pair. then the DG may become invalid.

3) no need to remove the DG (assuming that the group will have some members that you won't expand.

4 & 5 Absolutely correct. then add your device back to the group.

Hope that helps

Mohammed Salem

Hi Sun_deep451,

Welcome to EMC community.

Assuming that the device is replicated via SRDF, then you will have first to DELETE the pair. Expand R1 and R2 then recreate the pair with FULL establish. Unfortuinately there is no way to do that while replication is in place.

Expanding a Concatenated Meta dev is just adding a tail device at the end of your meta dev so if you have 8 members meta device you will just another the 9th member and will not be used untill the free block on the other meta members is zero.

The commands Arpit_joy suggested is correct. You can try it. Just make sure (whenever possible) to choose member of same size so that you can convert it to striped in the future if you need.

Hope that helps

Mohammed Salem

Thanks saleem,

i am having a little bit confusion only on replication itself

after deletion of pair, do we need to take out the dev from Dg or straight away we can go ahead for expansion.

steps for expansion

1) suspend the rdf group

2)delete the pair

3) do we need to remove dev from DG or we can expand directly?

4)expand r1 and r2

5)recreate the SRDF relationship

Suggest if am missing anysteps.

Thanks Saleem,

all Steps worked successfully.