Documentation/filesystems/ceph.rst

1 .. SPDX-License-Identifier: GPL-2.0
15  * N-way replication of data across storage nodes
17  * Automatic rebalancing of data on node addition/removal
27 separates data and metadata management into independent server
29 storage nodes run entirely as user space daemons.  File data is striped
31 facilitate high throughputs.  When storage nodes fail, data is
32 re-replicated in a distributed fashion by the storage nodes themselves
37 in-memory cache above the file namespace that is extremely scalable,
39 and can tolerate arbitrary (well, non-Byzantine) node failures.  The
46 independent metadata servers, allowing scalable concurrent access.
48 The system offers automatic data rebalancing/migration when scaling
50 requiring an administrator carve the data set into static volumes or
51 go through the tedious process of migrating data between servers.
66   `_<SNAPSHOT-NAME>_<INODE-NUMBER>`.  Since filenames in general can't have
67   more than 255 characters, and `<node-id>` takes 13 characters, the long
68   snapshot names can take as much as 255 - 1 - 1 - 13 = 240.
71 files and bytes.  That is, a 'getfattr -d foo' on any directory in the
82  setfattr -n ceph.quota.max_bytes -v 100000000 /some/dir
83  getfattr -n ceph.quota.max_bytes /some/dir
88 from writing as much data as it needs.
95  # mount -t ceph user@fsid.fs_name=/[subdir] mnt -o mon_addr=monip1[:port][/monip2[:port]]
103 …# mount -t ceph cephuser@07fe3187-00d9-42a3-814b-72a4d5e7d5be.cephfs=/ /mnt/ceph -o mon_addr=1.2.3…
110   # mount -t ceph cephuser@cephfs=/ /mnt/ceph -o mon_addr=mon-addr
114   # mount -t ceph cephuser@cephfs=/ /mnt/ceph -o mon_addr=192.168.1.100/192.168.1.101
129   fsid=cluster-id
149 	of a non-responsive Ceph file system.  The default is 60
166 	Disable CRC32C calculation for data writes.  If set, the storage node
167 	must rely on TCP's error correction to detect data corruption
168 	in the data payload.
190         Don't use the RADOS 'copy-from' operation to perform remote object
203 	  dirty data/metadata, invalidates page caches and writable file handles.
215 	- https://github.com/ceph/ceph-client.git