Removing a DAE on a EMC CLARiiON cx500

Posted on 2006-10-31
Last Modified: 2007-12-19
I want to remove a DAE on my Cx500.  I have no Raid Groups bound to any disks on the DAE (I have in the past for testing purposes, but nothing is there now).

I understand that I can turn off my entire SAN, unplug the DAE, then power it back on.  I'd rather not do this.

I believe I can...
Power down/unplug DAE (this will make my CLARiiON scream at me with faults until I fix it, but I don't think it will interrupt any I/O)
Reboot SPA, wait for it to come back up
Reboot SPB, wait for it to come back up
The DAE should be removed from NaviSphere.

Does anyone know if this will work?  Or if I need to reboot both SPs at the same time?
Question by:flood_land
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Expert Comment

by:Duncan Meyers
ID: 17845879
Providing that there are *no* RAID groups (including hot spares), and that there are no DAE's downstream, then you can unplug the DAE safely without the procedure you've listed. You can safely add and remove a DAE online providing those details listed above are adhered to. If you have DAEs downstream from the DAE you want to remove then you will need an outage. You must also *not* renumber the downstream (using the BCD switch between the PSUs) DAE or you will lose the data on that DAE.

You will get a system error light that will not clear until you reboot the array - which in this case means power the whole lot off then back on again. Rebooting the individual SPs will not clear the error light.

So yes, you can do what you want to do providing yadda yadda yadda.

Author Comment

ID: 17849707
Yeah.  I only have one DAE in addition to my DPE, so nothing else is on the DAE's expamsion backend loop.

The main thing I want to do is move the DAE to BE loop 1.  It's on 0 for some reason.  I was going to get it out of NaviSphere, then re-add it.

Sounds like it might be easier to just power it off, unplug the DAE, Power the DPE back on, Plug the DAE into BE loop 1 on ID 0, then turn the DAE on.
LVL 30

Accepted Solution

Duncan Meyers earned 500 total points
ID: 17853696
Its certainly no problem to do it live - but you'll need to reboot the array at some point to clear the error condition. You should also let EMC Support know because they'll freak out when they see a dial-home event with a whole DAE gone missing. :-)

I'm surprised that its on Loop 0 ID 1 - you're quite right - it should be on Loop 1 ID 0. It doesn't really make a blind bit of difference to the array performance, but its nice to set it up as per best practices.

Author Comment

ID: 17860060
Actually.  I got it to work without rebooting the SAN.

I did this
1. Made sure no Raid groups were bound to the DAE
2. Powered down DAE
3. Unplugged backend loop cables from Cx500
4. Typed this command for each SP. (navicli -h <ip of SP> remoteconfig -<engineering mode pw> -stop
5. Went into the http://<ip of sp>/setup and restarted the NaviSphere Management Server for each SP
6. Went back into NaviSphere and no faults and DAE was removed from NaviSphere.

LVL 30

Expert Comment

by:Duncan Meyers
ID: 17863329

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