CUA failover: Main and remote site

Question

Hello, We have two sites with one CUA and one CENTERA in each site. Centeras are replicated (bi-directional), and each CUA points to the Centera in his site. CUAs are configured as stand-alone Both CUAs have the same name, different IPs, so we only change the IP in the DNS to let users write in main or remote site (like a failover) using the same domain name. Like Centera POOLs are replicated, we expected to see the same data when pointing to remote CUA, but the POOLs appears empty and we have problems to write. Notice main CUA points to main Centera and remote CUA points to remote Centera. EMC did this configuration long time ago but seems not to as expected. I've opened a SR and support told me the following: 'The issue is with the failover not being success full. The production CUA should not be online, if they did a failover then the production CUA cannot be pingable otherwise the failover fails right away. And it's NOT supported to have 2 CUA's on the network with the same database (if the the two CUa’s are on the same network). In such cases its normal to have the CUA would appear empty.' Is there any way to have a failover of CUAs and CENTERAs, I mean, in case of a disaster in main site, how can we continue working in remote site? What could be a valid configuration for this? I saw there is a EA configuration but seems to points both CUAs to same CENTERA isn't it? Any help would be appreciated! Thanks in advance

holgerjakob_c0722c · Accepted Answer

Hi dsuarez

EA ist required for this setup. You'll have to start with a reinstallation of CUA on the target, then setting up EA. Failover is a manual task. Failing back is troublesome in the way that the ancient primary needs to be configured as ea standby for the secondary. Then fail back , then configure the ea again pointing to the secondary site.

See the Centera Universal Access Monitor & Admin Guide. There is a good chapter on CUA EA in there.

Holger

omarelmazny · Answer

Hello dsuarez

In order to have a fail over CUA in the DR you need to configure EA between the active CUA in the main site & a CUA in the DR site, you cannot have two active CUAs at the same time & sync between them. You can also point the DR CUA to the DR Centera pre & during fail over

Dr.diSousa · Answer

Hi, reading Centera Universal Access Monitor & Admin Guide

What I'm worried about is that DR CUA can see data in DR CENTERA in a failover situation.

Customer wrote in DR CUA but luckly there is not too much data and is being copied back to main CUA, so I can destroy DR CUA and reconfigure for EA.

I'll be back for any doubts after reading doc.

Thanks in advance for you both!!

Centera

Was this post helpful?