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author | Qiaowei Ren <qiaowei.ren@intel.com> | 2018-01-04 13:43:33 +0800 |
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committer | Qiaowei Ren <qiaowei.ren@intel.com> | 2018-01-05 11:59:39 +0800 |
commit | 812ff6ca9fcd3e629e49d4328905f33eee8ca3f5 (patch) | |
tree | 04ece7b4da00d9d2f98093774594f4057ae561d4 /src/ceph/doc/dev/rbd-export.rst | |
parent | 15280273faafb77777eab341909a3f495cf248d9 (diff) |
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>
Diffstat (limited to 'src/ceph/doc/dev/rbd-export.rst')
-rw-r--r-- | src/ceph/doc/dev/rbd-export.rst | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/src/ceph/doc/dev/rbd-export.rst b/src/ceph/doc/dev/rbd-export.rst new file mode 100644 index 0000000..0d34d61 --- /dev/null +++ b/src/ceph/doc/dev/rbd-export.rst @@ -0,0 +1,84 @@ +RBD Export & Import +=================== + +This is a file format of an RBD image or snapshot. It's a sparse format +for the full image. There are three recording sections in the file. + +(1) Header. +(2) Metadata. +(3) Diffs. + +Header +~~~~~~ + +"rbd image 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. + +Image order +----------- + +- u8: 'O' +- le64: length of appending data (8) +- le64: image order + +Image format +------------ + +- u8: 'F' +- le64: length of appending data (8) +- le64: image format + +Image Features +-------------- + +- u8: 'T' +- le64: length of appending data (8) +- le64: image features + +Image Stripe unit +----------------- + +- u8: 'U' +- le64: length of appending data (8) +- le64: image striping unit + +Image Stripe count +------------------ + +- u8: 'C' +- le64: length of appending data (8) +- le64: image striping count + +Final Record +~~~~~~~~~~~~ + +End +--- + +- u8: 'E' + + +Diffs records +~~~~~~~~~~~~~~~~~ +Record the all snapshots and the HEAD in this section. + +- le64: number of diffs +- Diffs ... + +Detail please refer to rbd-diff.rst |