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13 Posts
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1736
April 8th, 2016 16:00
Chaging EA of a populated DAE
Hello,
We are curently facing an issue or to be more precise, a "cosmetic" issue( if what I read is right, it's a cosmetic one:) )
We are having a CX3-20 system running 03.26.020.5.020 and the problem that we are having is that the sequence of the DAE IDs is not kept therefore we have:
DAE 0
DAE 1
DAE 3
All 3 DAEs are populated with productive data and we woulk like to fix this issue now, if possible, until we are not expanding the array. Possible scenarios and questions:
1) Shut down the whole array, poweron only DAE 3, change the enclosure address from 3 to 2 and then power on all the array - would this work or will lead to data coruption, the system not being able to see anymore the RGs and the LUNs from this DAE? I suppose that it won't work since the PSM area and the OS expects to find some RGs and LUNs on DAE 3, but worth asking...:)
2) Shut down the whole array, power on another DAE and set the enclosure address to 2, put this DAE physically in the daisy chain in between DAE 1 and DAE 3 and power on the whole array. Whould this work ?
3) Any other ideas of doing this without data corruption/loss ?
Regards,
Raul
kelleg
4.5K Posts
0
April 11th, 2016 09:00
You can NOT change the DAE Enclosure number once the disks in that enclosure have been configured - changing the number would cause you to lose all data on that enclosure.
Inserting a new DAE into the chain and setting the number to 2 would work, but it really doesn't matter where the number is located in the chain other than a proper numbering scheme.
I'd just add the new DAE to the end of the chain and called it 2. Anytime you mess with the cabling you run the risk of issues.
glen
ZaphodB
195 Posts
0
April 11th, 2016 07:00
First, you have a CX3-20...you should probably consider yourself lucky that it is still in working order (...due to age, not design, or reliability flaws...) and leave it alone.
But, while I have never actually done either, I would guess that option (1) is going to fail, but that option (2) would probably work. If you have another enclosure, and address it as '2', and insert it into the cabling in the proper location, the array would likely be able to work with that.
Regardless, I'd get a good set of backups first...
TheJudge1
13 Posts
0
April 11th, 2016 13:00
Thanks glen. I will go with the safer approach and just add the new DAE at the end of the chain and set its EA to 2.
Zaphod: Old does not necessary mean that's not realiable anymore. It's actually running well and our customers are satisfied with the performance since we do not put that much load on it. Thanks for feedback!
Regards,
Raul