Setting up CephFS
#What is CephFS
- CephFS is a POSIX file system that can be accessed by multiple clients
- Mounted directly via the Linux kernel or via FUSE and libcephfs
- Metadata (file names, directory contents, permissions, ...) and data kept in seperate pools
- Metadata is handled by an MDS (Metadata Server)
- Clients connect directly to OSDs to store/retrieve data.
#Metadata Servers (MDS)
MDS are required to get started with CephFS.
#How many MDS?
- Each file system can have any number of active MDS
- Each active MDS will need a separate passive failover MDS to take over
- For most cases one active MDS and one standby MDS is sufficient
- Multiple active MDS are typically used once you have > 100 million files...
- ...and a larger number of metadata operations or open files
#Setting up MDS
- Navigate to
http://mgmt-node:8080/services
- Press + MDS in the action bar at the bottom of your window
- Select at least two servers to use (1 active + 1 standby)
#More than one active MDS
Per default, there will always be only one active MDS. If you really do need more, you will have to set that manually.
- Navigate to
http://mgmt-node:8080/maintenance/terminal
- or connect to the management node per SSH if you prefer
- enter the following
ceph fs set cephfs max_mds 2#CephFS Explorer
Now you can test your CephFS with our built in CephFS Explorer: http://mgmt-node:8080/cephfs. You can move, copy and delete files like in any other file explorer by using the usual shortcuts.
