C Sébastien Han

Stacker! Cepher! What's next?

Start Considering Ceph as a Backend for OpenStack Cinder (to Replace LVM)

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Just back from the Juno summit, I attended most of the storage sessions and was extremely shocked how Ceph was avoided by storage vendors. However LVM, the reference storage backend for Cinder was always mentioned. Maybe, is it a sign that Ceph is taking over? Talking about LVM, the last OpenStack survey showed that it was the more used backend.

Ceph Maintenance With Ansible

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Following up this article.

This playbook was made to automate Ceph servers maintenance. The typical use case is an hardware change. By running this playbook you will set the noout flag on your cluster, which means that OSD can’t be marked as out of the CRUSH map, but they will be marked as down. Thus the OSD will not receive any data. Basically we tell the cluster to do not move any data since the operation will not last for too long.

Don’t Burn Down Your OpenStack Cloud

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Managing an OpenStack public cloud can be tough and building it properly is even harder. You can not predict the workload of your platform, customers do what they want (yes they pay for this!). So yes, cloud performance are often unpredictable! Recent studies showed that while running a long-standing benchmark on several cloud platforms, they experienced a performance drop-down of 40% (crazy isn’t it?). However, there are some simple facilities in OpenStack that allow you to have a better control of the resources that you offer to your customers/users. This is what I am going to briefly explore in this article.