CephNotes

Some notes about Ceph
Laurent Barbe @SIB

Intel 520 SSD journal

A quick check of my Intel 520 SSD that running since 2 years on a small cluster.

smartctl -a /dev/sda
=== START OF INFORMATION SECTION ===
Model Family:     Intel 520 Series SSDs
Device Model:     INTEL SSDSC2CW060A3
Serial Number:    CVCV305200NB060AGN
LU WWN Device Id: 5 001517 8f36af9db
Firmware Version: 400i …

RadosGW big index

$ rados -p .default.rgw.buckets.index listomapkeys .dir.default.1970130.1 | wc -l
166768275

With each key containing between 100 and 250 bytes, this make a very big object for rados (several GB)... Especially when migrating it from an OSD to another (this will lock all writes), moreover, the OSD …

OpenVZ: kernel 3.10 with rbd module

3.X Kernel for OpenVZ is out and it is compiled with rbd module:

root@debian:~# uname -a
Linux debian 3.10.0-3-pve #1 SMP Thu Jun 12 13:50:49 CEST 2014 x86_64 GNU/Linux

root@debian:~# modinfo rbd
filename:       /lib/modules/3.10.0-3-pve …

Ceph Pool Migration

You have probably already be faced to migrate all objects from a pool to another, especially to change parameters that can not be modified on pool. For example, to migrate from a replicated pool to an EC pool, change EC profile, or to reduce the number of PGs... There are …

RadosGW: Simple replication example

This is a simple example of federated gateways config to make an asynchonous replication between two Ceph clusters.

RadosGW replication example

(Update Nov. 2016 : Since Jewel version, radosgw-agent is no more needed and active-active replication between zone is now supported. See here : http://docs.ceph.com/docs/jewel/radosgw/multisite/)

( The configuration below …