Steps for cascade SRDF

Question

Hi Folks , I am ware of the Cascade SRDF conceptually but i just want to note down how it will be implemeted step by step. I tried lot to search into powerlink PDF's which will help me to note down the commands but i am unlucky. Can some one help with commands and validate my below steps. Please feel free to add if i am missing anything. Example : Site A --> Site B --> Site C  ( Assuming all site having dynamic SRDF bit enabled ) Step 1 : Setup SRDF between devices on Site A and  Site B - Its very easy using 'createpair command ' Step 2 : Make R2 device on Site B as R21 - Not sure how to do this , also not sure if we need to do this manually using commands. Step 3:  Setup SRDF between devices on Site B and  Site C - Should be easy using 'createpair command ' only if the Site B device is in R21 state. Thanks in Advance. Regards OnlySandy

sauravrohilla · Accepted Answer

Hi Sandy,I can help you in setting up the cascaded srdf.E.g:Step 1: create a text file with <025 035>symrdf -sid siteA -rdfg 10 createpair -f -type r1 Step 2: create another text file <035 045>symrdf -sid siteB -rdfg 20 createpair -f -type r1 -rdf_mode acp_disk After running createpair at Site B, the device 035 will be converted to a R21 device.Hope this helps..regards,Saurabh

OnlySandy · Answer

Oh thants pretty straight forward. I thought we need to convert device to R21 but that not required.

Gr8 help thanks Saurabh.

Just a query is there any requirments to be satisfied before doing step2 . I am aware that second replication cant be in Sync mode . Any other limitations

sauravrohilla · Answer

Hi,

As you already know the second leg cant be in sync mode and by default createpair command puts the pair in sync mode thats why I have added the -rdf_mode acp_disk option to put the second pairing in acp_mode while creating.

The first pair establish might ask you to provide -force option. need to check on that.

regards,

Saurabh

Symmetrix

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