Hi hope someone can help me here. I'm practicing configuring data guard and rac. I have configured data guard on the one vm with two instances without any problem. My problem comes from when I attempt to connect two separate VM's for data guard or RAC. Incidentally something to note when I configure grid infrastructure for RAC there is no problem connecting and configuring the two machines for Grid.
Hardware - Mac Powerbook using wireless connection OS Lion
Software:
Latest version of Virtualbox
Oracle Linux 6.5
Oracle database 11.2.0.2
Networking:
One NAT connector using the 10.0.2.0 network with a 24 bit mask (don't use bridged as mac laptops using wireless don't get on with bridged)
One internal network adapter using the 192.168.2.0 network with a 24 bit mask used for connecting VM's
Nearly all posts I see mention about host to VM problems etc and have seen a few on problems with various adapters etc but none on my problem of tns between VM's.
1. I can ssh between the two VMs ok whether using /etc/hosts file or dns I set up when I want scan addresses to work as they don't seem to like using name resolution taken from the hosts file.
2. I have eliminated the possibility of tnsnames.ora or listener.ora being the problem by using the same configurations on a one VM data guard configuration (copying pasting then changing server name ) etc. I have also done things like create two VMs one called db1 and the other called db2 with sids of orcl and orclstdby keeping it simple with both instances working perfectly in their own containers. In all cases I have been able to get ssh working with both server names and IP's.
3. Sorry at work on break so can't post up my tnsnames.ora or listener.ora but I have tested them to death. I've created them manually I've used netmgr I've replaced db1 and db2 with respective IPs. lsnrctl reload tells me it's happily listening on port 1521 and using tnsping on each machine that can ping itself. I can ssh between host and both databases work perfectly on their own.
4. I even then took both machines on their own right and created data guard with two instances running on the same VMs using DBA Dans tutorial on youtube as it was driving me crazy and wanted to practice as that's how I learn. I copied tns info from db1 to db2 and the other way round for the other set up and it worked. All I had to do was change the server name in the part of the TNS that I copied over.
5. Oh yes and nearly forgot have disabled firewall and used chkconfig to keep it off and also done all the other stuff like editing /etc/selinux/config
No matter what I do though I keep getting the error ORA-12154: TNS: could not resolve... when I try to connect between VM's and its only for tns not ssh etc. Data guard on one VM no problem, Grid infrastructure with ASM no problem on two VM's but I can't go any further with RAC or Data Guard until I can create a tns connection between devices.
Any advice on this would be greatly appreciated.
David Fullstone