From 812ff6ca9fcd3e629e49d4328905f33eee8ca3f5 Mon Sep 17 00:00:00 2001
From: Qiaowei Ren <qiaowei.ren@intel.com>
Date: Thu, 4 Jan 2018 13:43:33 +0800
Subject: initial code repo

This patch creates initial code repo.

For ceph, luminous stable release will be used for base code,
and next changes and optimization for ceph will be added to it.

For opensds, currently any changes can be upstreamed into original
opensds repo (https://github.com/opensds/opensds), and so stor4nfv
will directly clone opensds code to deploy stor4nfv environment.
And the scripts for deployment based on ceph and opensds will be
put into 'ci' directory.

Change-Id: I46a32218884c75dda2936337604ff03c554648e4
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
---
 src/ceph/doc/dev/rbd-diff.rst | 146 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 src/ceph/doc/dev/rbd-diff.rst

(limited to 'src/ceph/doc/dev/rbd-diff.rst')

diff --git a/src/ceph/doc/dev/rbd-diff.rst b/src/ceph/doc/dev/rbd-diff.rst
new file mode 100644
index 0000000..083c131
--- /dev/null
+++ b/src/ceph/doc/dev/rbd-diff.rst
@@ -0,0 +1,146 @@
+RBD Incremental Backup
+======================
+
+This is a simple streaming file format for representing a diff between
+two snapshots (or a snapshot and the head) of an RBD image.
+
+Header
+~~~~~~
+
+"rbd diff v1\\n"
+
+Metadata records
+~~~~~~~~~~~~~~~~
+
+Every record has a one byte "tag" that identifies the record type,
+followed by some other data.
+
+Metadata records come in the first part of the image.  Order is not
+important, as long as all the metadata records come before the data
+records.
+
+From snap
+---------
+
+- u8: 'f'
+- le32: snap name length
+- snap name
+
+To snap
+-------
+
+- u8: 't'
+- le32: snap name length
+- snap name
+
+Size
+----
+
+- u8: 's'
+- le64: (ending) image size
+
+Data Records
+~~~~~~~~~~~~
+
+These records come in the second part of the sequence.
+
+Updated data
+------------
+
+- u8: 'w'
+- le64: offset
+- le64: length
+- length bytes of actual data
+
+Zero data
+---------
+
+- u8: 'z'
+- le64: offset
+- le64: length
+
+
+Final Record
+~~~~~~~~~~~~
+
+End
+---
+
+- u8: 'e'
+
+
+Header
+~~~~~~
+
+"rbd diff v2\\n"
+
+Metadata records
+~~~~~~~~~~~~~~~~
+
+Every record has a one byte "tag" that identifies the record type,
+followed by length of data, and then some other data.
+
+Metadata records come in the first part of the image.  Order is not
+important, as long as all the metadata records come before the data
+records.
+
+In v2, we have the following metadata in each section:
+(1 Bytes) tag.
+(8 Bytes) length.
+(n Bytes) data.
+
+In this way, we can skip the unrecognized tag.
+
+From snap
+---------
+
+- u8: 'f'
+- le64: length of appending data (4 + length)
+- le32: snap name length
+- snap name
+
+To snap
+-------
+
+- u8: 't'
+- le64: length of appending data (4 + length)
+- le32: snap name length
+- snap name
+
+Size
+----
+
+- u8: 's'
+- le64: length of appending data (8)
+- le64: (ending) image size
+
+Data Records
+~~~~~~~~~~~~
+
+These records come in the second part of the sequence.
+
+Updated data
+------------
+
+- u8: 'w'
+- le64: length of appending data (8 + 8 + length)
+- le64: offset
+- le64: length
+- length bytes of actual data
+
+Zero data
+---------
+
+- u8: 'z'
+- le64: length of appending data (8 + 8)
+- le64: offset
+- le64: length
+
+
+Final Record
+~~~~~~~~~~~~
+
+End
+---
+
+- u8: 'e'
-- 
cgit 1.2.3-korg