Calculating the storage overhead of a replicated pool in Ceph is easy. You divide the amount of space you have by the “size” (amount of replicas) parameter of your storage pool. Let’s work with some rough numbers: 64 OSDs of 4TB each. Raw size: 64 * 4 = 256TB Size 2 : 128 / 2 = 128TB Size 3 : 128 / 3 = 85.33TB Replicated pools are expensive in terms of overhead: Size 2 provides the same resilience and overhead as RAID-1.
I’ve just drafted a new release of python-cephclient on PyPi: v0.1.0.5. After learning about the ceph-rest-api I just had to do something fun with it. In fact, it’s going to become very handy for me as I might start to develop with it for things like nagios monitoring scripts. The changelog: dmsimard: Add missing dependency on the requests library Some PEP8 and code standardization cleanup Add root “PUT” methods Add mon “PUT” methods Add mds “PUT” methods Add auth “PUT” methods Donald Talton:
I’m glad to announce that Ceph is now part of the mirrors iWeb provides. It is available in both IPv4 and IPv6 by: http on http://mirror.iweb.ca/ or directly on http://ceph.mirror.iweb.ca/ rsync on ceph.mirror.iweb.ca::ceph The mirror provides 4 Gbps of connectivity and is located on the eastern coast of Canada, more precisely in Montreal, Quebec. We feel this complements very well the principal ceph mirror at ceph.
I’ve always been a fan of nginx, it was love at first sight. I tend to use nginx first and foremost as a reverse proxy server for web content and applications. This means that nginx sends your request to backend servers and forwards you their response. Some examples of backend servers I use: php5-fpm for PHP gunicorn or wsgi for Python PSGI/Plack or fastcgi for Perl Now, the cool thing is that these backend servers are good at what they do: serve code and applications written in specific languages.
You might have heard this already but Redhat made an annoucement last week that they will be acquiring Inktank, the company behind Ceph. Inktank steered Ceph’s development, offered training and provided support through an entreprise package which included Calamari: a web interface to have insight on what is going on inside your cluster. You can have a peek at what Calamari looks like here - in a session from Portland’s Openstack Summit.