STD 8GB device expand

Question

Hello all, I have a question regarding meta expansion. We have some 8GB std devices mapped & masked to servers. Now we need to add more storage and thought of expanding those devices. Is this achivable ? these are also R1 devices being replicated. thanks, Ramesh

dynamox · Answer

if it's a standard device you will need to unmap it first, expand it and map it back. If it's meta already you can expand online. Looks like you already asked this question regarding expansion and SRDF

https://forums.emc.com/forums/thread.jspa?messageID=623213򘉭

Manumari · Answer

thanks Dynamox. Yes I know I did ask a question but it was about rdf pairing and did come to know that not possible with out deleting the pair. But this one was want to make sure that I need to unmap before I proceed.

So would that impact any data on the device? also does it requires unmasking too? So since its a R1 STD , then I guess i need to unmap, delete rdf pair then expand and redo everything if I am correct.

xe2sdc · Answer

You are right IMHO .. 1) unmap2) remove RDF pairing3) expand device (form new meta/expand existing one) on both arrays4) form RDF pair5) establish 6) while establishing, map device on the frontend.No need to unmask.

Manumari · Answer

Great. thanks much for both you letting me know.

Manumari · Answer

Forgot to ask. Would there be any data loss while converting from STD to meta device ?

dynamox · Answer

actually ...let me re-phrase that ...i've done concatenated expansions like that. I don't think your data will survive if you create a striped meta without using a BCV to protect the data. The option is "protect_data=TRUE"

Take a look at these solutions: emc90041, emc166979

dynamox · Answer

not at all ..data will be intact but you will need to do some work on the host side to realize the extra capacity you gained.

duggivarun · Answer

let me correct if i am wrong...

a)we cannot expand a std device to meta when it is online. we need to unmap it and expand it and map again.

b)we can expand an existing meta online with out unmapping.

c)if the std device has srdf pair. we need to first split the pair and unmap the std and expand it.

d)if the meta device has srdf pair.we need to split the pair and expand it.

dynamox · Answer

things changed since 2009 and VMAX can do much more than DMX ..so it depends what platform/code level you are referring to.

duggivarun · Answer

I mean both dmx(5773) and vmax(5874).

dynamox · Answer

take a look at this discussion

https://community.emc.com/thread/117240?start=15&tstart=0

but based on your current platform/code:

a) correct

b) correct

c) not only split, you will need to delete SRDF relationship, expand source and target and re-create SRDF (full sync)

d) same as c

duggivarun · Answer

thank you dynamox

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