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[Qemu-devel] [PING] [PATCH v0 0/3] add zstd cluster compression
From: |
Denis Plotnikov |
Subject: |
[Qemu-devel] [PING] [PATCH v0 0/3] add zstd cluster compression |
Date: |
Tue, 4 Jun 2019 07:56:49 +0000 |
On 28.05.2019 17:37, Denis Plotnikov wrote:
> The goal of the patch-set is to enable qcow2 to use zstd compression for
> clusters. ZSTD provides better (de)compression performance than currently
> used ZLIB. Using it will improve perforamnce (reduce compression time)
> when the compressed clusters is used, e.g backup scenarios.
>
> Also, the patch-set extends qcow2 specification by adding compression_type
> feature. The feature enables adding ZSTD and another compression algorithms
> in the future.
>
> Here is some measurements ZSTD vs ZLIB:
>
> The test:
> Test compresses and decompresses qemu qcow2 image with just
> installed rhel-7.6 guest.
> Image cluster size: 64K. Image on disk size: 2.2G
>
> The test was conducted with brd disk to reduce the influence
> of disk subsystem to the test results.
> The results is given in seconds.
>
> compress cmd:
> time ./qemu-img convert -O qcow2 -c -o compression_type=[zlib|zstd]
> src.img [zlib|zstd]_compressed.img
> decompress cmd
> time ./qemu-img convert -O qcow2
> [zlib|zstd]_compressed.img uncompressed.img
>
>
> The results:
> compression decompression
> zlib zstd zlib zstd
> ------------------------------------------------------------
> real 65.5 16.3 (-75 %) 1.9 1.6 (-16 %)
> user 65.0 15.8 5.3 2.5
> sys 3.3 0.2 2.0 2.0
>
> Both ZLIB and ZSTD gave the same compression ratio: ~1.5
> compressed image size in both cases: ~1.4G
>
> Denis Plotnikov (3):
> qcow2: introduce compression type feature
> qcow2: add compression type processing
> qcow2: add zstd cluster compression
>
> block/qcow2.c | 240 ++++++++++++++++++++++++++++++++++++--
> block/qcow2.h | 29 +++--
> configure | 26 +++++
> docs/interop/qcow2.txt | 37 +++++-
> include/block/block_int.h | 1 +
> qapi/block-core.json | 34 +++++-
> 6 files changed, 348 insertions(+), 19 deletions(-)
>
--
Best,
Denis
- [Qemu-devel] [PING] [PATCH v0 0/3] add zstd cluster compression,
Denis Plotnikov <=