How a device with SRDF R1 type is created?

Question

I am sorry, if you feel this is a very basic question.

When I run symdev list -r1, it will list all devices with R1 type. How are these devices created?

Are following steps to create R1 deivce:

symdg create -type RDF1 myrdfgrp

symld -sid 123 -g myrdfgrp add dev 087 DEV087

then after that, dev 087 will become R1 type? If yes, then what is the reason behind that when I run symdev show 087, it will not tell me the group name "myrdfgrp"?

Thank you!

Sridhar246 · Accepted Answer

Page 44 on EMC Solutions Enabler Symmetrix Array Controls CLI V7.6 Product Guide

create dev count=n,

size=n [MB |GB | CYL],

emulation=EmulationType,

config=DeviceConfig,

[, data_member_count=nn]

[, remote_config=DeviceConfig,

remote_data_member_count=nn,

ra_group=n, [remote_mvs_ssid=nnn],

[dynamic_capability=[dyn_rdf | dyn_rdf1_only | dyn_rdf2_only]]

[, mvs_ssid=nnn]

Specifying dyn_rdf will make the device srdf capable and can be used as both R1 or R2 device.

dynamox · Answer

emcmagic,

you should really spend some time and go over these documents. Not only will you find answers to your questions but you will better understand how to manage this platform, different feature set ..etc.

https://support.emc.com/docu46994_Solutions-Enabler-7.6-Complete-Documentation-Set.pdf

emcmagic · Answer

I have been checking the document.

The device with R1 type has to be somehow there first before I can run symld to add it into RDF1 group, but still don't know how R1 type is created in the first place.

Still checking...

lingtan · Answer

Is it 'symdg create r1_devg_001 -type RDF1'? The Techbook 'Using EMC SRDF to Facilitates Disaster Recovery for DB2' has some examples.

emcmagic · Answer

I know how to create RDF1 group, and then add R1 devices into the group via symld. I just don't know how to create R1 devices prior to these two steps...

dynamox · Answer

when you open documentation set, click on Files (at the top) and then open EMC Solutions Enabler Symmetrix SRDF Familty CLI 7.6 Product Guide. They explain what SRDF is, how it works and provide example how to build SRDF relationship.

lingtan · Answer

Can someone give some real working examples of using symconfigure "create dev" to create logical devices? May be this would help. I dont find too many examples in "Solution Enabler Array Management CLI".

dynamox · Answer

Check Solutions Enabler Symmetrix Array Controls CLI

sauravrohilla · Answer

to create r1 device, use the config option in create dev command and give the appropriate value. A table on the possible device config is given in the symcli guide. regards, Saurabh

sauravrohilla · Answer

symconfigure -sid xxx -cmd 'create dev count=1,size=1 gb, config=2-way-mir,emulation=fba,disk_group=1;' commit this will create a raid 1 device of size 1 gb from disk group 1 and emulation type fba. regards, Saurabh

emcmagic · Answer

Hi Saurabh,

How would you indicate the device created by your command is R1 type? I thought before you create RDF1 group, and add the device into the group, the device has to be R1 type. Is that right? Or what would you do to make it as R1 type?

I have checked the document, but could not find it on my own.

Thank you!

dynamox · Answer

device group is just a logical container where you place devices of certain type, it does not change device protection nor other characteristics.

Did you have a chance to read the document i linked to earlier ? I can give you the steps all day long but if you don't understand what you are doing and just follow the steps ..you can easily make mistakes and overwrite production data.

lingtan · Answer

If devices are create without specifying dynamic_capability - is dyn_rdf the default? Also, I found another example in DB2/SRDF Techbook where you can set the dynamic capability after the device is created:

symconfigure -sid xxx -cmd "set dev 0090:0091 attribute=dyn_rdf;" -v noprompt commit

emcmagic · Answer

You answered my question. Thank you! I got stuck on this particular step, and neglected this option. If I could get remind of, that would save me a lot of time.

dynamox · Answer

keep in mind that setting RDF attribute does not mean that device is an R1 or an R2 until you build that relationship.

VMAX

How a device with SRDF R1 type is created?

Was this post helpful?