In this post we’ll be setting up a 2-node 18.104.22.168 RAC on Oracle Linux 6.5, and the end goal is to have a fully configured cluster with 2 databases available (1 RAC, 1 RAC One Node)
The machines are called orarac03/04 and they have just been kickstarted. As part of that process a ‘deploy’ user (ansible) has been added, with ssh-keys to make sure passwordless ssh is possible from the control machine. The user also have passwordless sudo privileges.
Note: You don’t necessarily need to have everything passwordless (login, sudo etc), as Ansible can ask for all that at the start of a play but it naturally makes things easier if you can.
The ansible user will be used in the playbooks and will sudo to the other users as needed.
The hosts have been equipped with:
- One 16GB device (/dev/sda)
- One 50GB device
- 6 devices for shared storage.
- 2 NIC’s, one for the public network and one for the interconnect. Only the public (eth0) is configured
- 2 cores/8 GB RAM
This turned out to be a rather lenghty post, so consider yourself warned.
This is a description of the parameters available to all the roles. I will not go into a lot of detail, as they may change. For the most up to date description look at the github page.
I made a few assumptions upfront when creating the roles, and I fully intend to make all of them configurable, but for now:
- The Oracle user only belongs to one group (dba). I’ll add more groups later
- Using ASMlib for the ASM disks. You might want to be able to use udev or something else
- Not bonding your network interfaces (using ansible facts to pick out information about eth0 & eth1)
- Using Flex ASM
- External redundancy for all diskgroups
- Use of AL32UTF8/AL16UTF16 (this might not change)
- Multipathing is not configured by the roles so that is something you’d have to do yourself.
- Only Admin managed databases
In this post I thought we’d quickly go through the existing roles that are used in doing the RAC-install and see what they do. There are a few other roles as well, which are not being used at the moment, so we’ll not go through them.
The following roles are also used when setting up a Grid Infrastructure in a Stand-alone configuration (Oracle Restart)
Below is pretty much a copy of the README.md from the Github page.
The different roles are:
common: This will configure stuff common to all machines
- Install some generic packages
- Configure ntp
- Possibly add a default/deploy user.
orahost: This will configure the host specific Oracle stuff:
- Add a user & group (at the moment only a dba group)
- Create directory structures
- Generate ssh-keys and set up passwordless ssh between clusternodes in case of RAC/RAC One node
- Handle filesystem storage (partition devices, creates vg/lv and a ext4 filesystem etc).
- Install required packages
- Change kernel parameters
- Set up pam.d/limits config
- Configures Hugepages (as a percentage of total RAM)
- Disables transparent hugepages
- Disables NUMA (if needed)
- Configures the interconnect network (if needed)
- Configures Oracle ASMLib
I’m a big fan of automation and configuration management. It makes life a lot easier when it comes to installing and configuring (whatever there is you’re installing and configuring), and also less error prone. And that is where configuration management tools like Ansible, Puppet, Chef & Saltstack comes into play. They help you enforce state on your hosts, which makes keeping things in line easy. You just update your manifest (in the Puppet-case) and soon after the agent on the managed hosts checks in with the master, all your hosts have applied the change. It doesn’t matter if you’re managing 1, 50, 500 or 5000 hosts, you just make the change once and the tool does all the rest. I mean, whats not to like about that?
So, about a decade after everyone else I thought I’d give this blogging thing a go.
My name is Mikael Sandström and I’m an Oracle Database engineer working and living in Stockholm, Sweden.
I guess this will be mostly about tech stuff that interests me, like Oracle, Infrastructure, Virtualization, Automation, Configuration Management, Software defined whatevers. Maybe also other stuff, we’ll see.