Testing resource recovery

Posted on Tue 04 December 2012 in hints-and-kinks • Tagged with Galera, MySQL, Pacemaker

If MySQL happens to die in your cluster, Pacemaker will automatically recover the service in place. To test this, select any node on your cluster and send the mysqld process a KILL signal:

killall -KILL mysqld

Then, monitor your cluster status with crm_mon -rf. After a few seconds, you should …


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Migrating virtual machines from block-based storage to RADOS/Ceph

Posted on Mon 22 October 2012 in hints-and-kinks • Tagged with Ceph, libvirt

Ceph allows you to replace existing SAN storage (or SAN drop-in substitutes) with a flexible storage solution with real scale-out capabilities. Here is how you migrate existing virtual machines managed by libvirt from block-based storage to a Ceph based storage solution.

Prerequisites

What you'll need in order to successfully manage …


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Maintenance in active Pacemaker clusters

Posted on Mon 24 September 2012 in hints-and-kinks • Tagged with Pacemaker

In a Pacemaker cluster, as in a standalone system, operators must complete maintenance tasks such as software upgrades and configuration changes. Here's what you need to keep Pacemaker's built-in monitoring features from creating unwanted side effects.

Maintenance mode

This is quite possibly Pacemaker's single most useful feature for cluster maintenance …


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Configuring radosgw to behave like Amazon S3

Posted on Mon 09 July 2012 in hints-and-kinks • Tagged with Ceph

If you've heard of Ceph, you've surely heard of radosgw, a RESTful gateway interface to the RADOS object store. You've probably also heard that it provides a front-end interface that is compatible with Amazon's S3 API.

The question remains, if you have an S3 client that always assumes it can …


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Fencing in VMware virtualized Pacemaker nodes

Posted on Fri 18 May 2012 in hints-and-kinks • Tagged with Pacemaker

For users of VMware virtualization, it's becoming increasingly common to deploy Pacemaker clusters within the virtual infrastructure. Doing this requires that you set up fencing via ESX Server or, more commonly, vCenter. Here's how to do that.

The cluster-glue package contains node Pacemaker's fencing (STONITH) plugins, one of which is …


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