summaryrefslogtreecommitdiffstats
path: root/doc/man/8/ceph-dencoder.rst
diff options
context:
space:
mode:
Diffstat (limited to 'doc/man/8/ceph-dencoder.rst')
-rw-r--r--doc/man/8/ceph-dencoder.rst151
1 files changed, 151 insertions, 0 deletions
diff --git a/doc/man/8/ceph-dencoder.rst b/doc/man/8/ceph-dencoder.rst
new file mode 100644
index 000000000..ef7e972b8
--- /dev/null
+++ b/doc/man/8/ceph-dencoder.rst
@@ -0,0 +1,151 @@
+:orphan:
+
+==============================================
+ ceph-dencoder -- ceph encoder/decoder utility
+==============================================
+
+.. program:: ceph-dencoder
+
+Synopsis
+========
+
+| **ceph-dencoder** [commands...]
+
+
+Description
+===========
+
+**ceph-dencoder** is a utility to encode, decode, and dump ceph data
+structures. It is used for debugging and for testing inter-version
+compatibility.
+
+**ceph-dencoder** takes a simple list of commands and performs them
+in order.
+
+Commands
+========
+
+.. option:: version
+
+ Print the version string for the **ceph-dencoder** binary.
+
+.. option:: import <file>
+
+ Read a binary blob of encoded data from the given file. It will be
+ placed in an in-memory buffer.
+
+.. option:: export <file>
+
+ Write the contents of the current in-memory buffer to the given
+ file.
+
+.. option:: list_types
+
+ List the data types known to this build of **ceph-dencoder**.
+
+.. option:: type <name>
+
+ Select the given type for future ``encode`` or ``decode`` operations.
+
+.. option:: skip <bytes>
+
+ Seek <bytes> into the imported file before reading data structure, use
+ this with objects that have a preamble/header before the object of interest.
+
+.. option:: decode
+
+ Decode the contents of the in-memory buffer into an instance of the
+ previously selected type. If there is an error, report it.
+
+.. option:: encode
+
+ Encode the contents of the in-memory instance of the previously
+ selected type to the in-memory buffer.
+
+.. option:: dump_json
+
+ Print a JSON-formatted description of the in-memory object.
+
+.. option:: count_tests
+
+ Print the number of built-in test instances of the previously
+ selected type that **ceph-dencoder** is able to generate.
+
+.. option:: select_test <n>
+
+ Select the given built-in test instance as the in-memory instance
+ of the type.
+
+.. option:: get_features
+
+ Print the decimal value of the feature set supported by this version
+ of **ceph-dencoder**. Each bit represents a feature. These correspond to
+ CEPH_FEATURE_* defines in src/include/ceph_features.h.
+
+.. option:: set_features <f>
+
+ Set the feature bits provided to ``encode`` to *f*. This allows
+ you to encode objects such that they can be understood by old
+ versions of the software (for those types that support it).
+
+Example
+=======
+
+Say you want to examine an attribute on an object stored by ``ceph-osd``. You can do this:
+
+::
+
+ $ cd /mnt/osd.12/current/2.b_head
+ $ attr -l foo_bar_head_EFE6384B
+ Attribute "ceph.snapset" has a 31 byte value for foo_bar_head_EFE6384B
+ Attribute "ceph._" has a 195 byte value for foo_bar_head_EFE6384B
+ $ attr foo_bar_head_EFE6384B -g ceph._ -q > /tmp/a
+ $ ceph-dencoder type object_info_t import /tmp/a decode dump_json
+ { "oid": { "oid": "foo",
+ "key": "bar",
+ "snapid": -2,
+ "hash": 4024842315,
+ "max": 0},
+ "locator": { "pool": 2,
+ "preferred": -1,
+ "key": "bar"},
+ "category": "",
+ "version": "9'1",
+ "prior_version": "0'0",
+ "last_reqid": "client.4116.0:1",
+ "size": 1681,
+ "mtime": "2012-02-21 08:58:23.666639",
+ "lost": 0,
+ "wrlock_by": "unknown.0.0:0",
+ "snaps": [],
+ "truncate_seq": 0,
+ "truncate_size": 0,
+ "watchers": {}}
+
+Alternatively, perhaps you wish to dump an internal CephFS metadata object, you might
+do that like this:
+
+::
+
+ $ rados -p metadata get mds_snaptable mds_snaptable.bin
+ $ ceph-dencoder type SnapServer skip 8 import mds_snaptable.bin decode dump_json
+ { "snapserver": { "last_snap": 1,
+ "pending_noop": [],
+ "snaps": [],
+ "need_to_purge": {},
+ "pending_create": [],
+ "pending_destroy": []}}
+
+
+Availability
+============
+
+**ceph-dencoder** is part of Ceph, a massively scalable, open-source, distributed storage system. Please
+refer to the Ceph documentation at https://docs.ceph.com for more
+information.
+
+
+See also
+========
+
+:doc:`ceph <ceph>`\(8)