Ceph: Introduction to Ceph

Whether you want to provide Ceph Object Storage and/or Ceph Block Device services to Cloud Platforms, deploy a Ceph Filesystem or use Ceph for another purpose, all Ceph Storage Cluster deployments begin with setting up each Ceph Node, your network and the Ceph Storage Cluster. A Ceph Storage Cluster requires at least one Ceph Monitor and at least two Ceph OSD Daemons. The Ceph Metadata Server is essential when running Ceph Filesystem clients.

Ceph stores a client’s data as objects within storage pools. Using the CRUSH algorithm, Ceph calculates which placement group should contain the object, and further calculates which Ceph OSD Daemon should store the placement group. The CRUSH algorithm enables the Ceph Storage Cluster to scale, rebalance, and recover dynamically.

Hard Ware Recommendations

The latest Hardware recommendations can be found on the Ceph Website.

OS Recommendations

EMPEROR (0.72)
Distro	Release	Codename	Kernel	Notes	testing
Ubuntu	12.04	Precise Pangolin	linux-3.2.0	1, 2	B, I, C
Ubuntu	12.10	Quantal Quetzal	linux-3.5.4	2, 4	B
Ubuntu	13.04	Raring Ringtail	linux-3.8.5	4	B
Debian	6.0	Squeeze	linux-2.6.32	1, 2, 3	B
Debian	7.0	Wheezy	linux-3.2.0	1, 2	B
CentOS	6.3	N/A	linux-2.6.32	1, 2	B, I
RHEL	6.3		linux-2.6.32	1, 2	B, I
Fedora	18.0	Spherical Cow	linux-3.6.0		B
Fedora	19.0	Schrödinger’s Cat	linux-3.10.0		B
OpenSuse	12.2	N/A	linux-3.4.0	2	B

DUMPLING (0.67)
Distro	Release	Codename	Kernel	Notes	testing
Ubuntu	12.04	Precise Pangolin	linux-3.2.0	1, 2	B, I, C
Ubuntu	12.10	Quantal Quetzal	linux-3.5.4	2	B
Ubuntu	13.04	Raring Ringtail	linux-3.8.5		B
Debian	6.0	Squeeze	linux-2.6.32	1, 2, 3	B
Debian	7.0	Wheezy	linux-3.2.0	1, 2	B
CentOS	6.3	N/A	linux-2.6.32	1, 2	B, I
RHEL	6.3		linux-2.6.32	1, 2	B, I
Fedora	18.0	Spherical Cow	linux-3.6.0		B
Fedora	19.0	Schrödinger’s Cat	linux-3.10.0		B
OpenSuse	12.2	N/A	linux-3.4.0	2	B

Notes

1. The default kernel has an older version of btrfs that we do not recommend for ceph-osd storage nodes. Upgrade to a recommended kernel or use XFS or ext4.
2. The default kernel has an old Ceph client that we do not recommend for kernel client (kernel RBD or the Ceph file system). Upgrade to a recommended kernel.
3. The default kernel or installed version of glibc does not support the syncfs(2) system call. Putting multiple ceph-osd daemons using XFS or ext4 on the same host will not perform as well as they could.
4. Ceph provides ARM support for Quantal and Raring. Saucy support is not supported yet, but support is coming soon.

TESTING

B: We continuously build all branches on this platform and exercise basic unit tests. We build release packages for this platform. I: We do basic installation and functionality tests of releases on this platform. C: We run a comprehensive functional, regression, and stress test suite on this platform on a continuous basis. This includes development branches, pre-release, and released code.