概述
两天前，简单写了篇bzip2 与 pbzip2 压缩哪个更快，当时是处于使用esrally压测Elastic search性能，并没有太多的关注几种压缩工具的性能如何。本文介绍常用的几种压缩命令，分别汇总出各个命令的压缩&解压缩全方面性能对比。
准备工作
看了下gzip，bzip2，pbzip2，xz这4个命令的help信息，帮助信息比较相似：
准备了一个测试文件方便测试：
root@node244:/mnt/disk/compress_test# ll
total 557704
drwxr-xr-x 2 root root 4096 Jun 3 10:34 ./
drwxr-xr-x 5 root root 4096 Jun 3 10:32 ../
-rw-r--r-- 1 root root 571073631 Jun 3 10:33 ceph-client.radosgw.0.log
root@node244:/mnt/disk/compress_test#
结合各个命令的help信息，可以使用简单的shell命令来完成测试工作，例如：
for i in {1..9}; do echo "============================ Compress Level $i ==========================="; echo " ----- Compress -----"; time gzip -k -f -$i ceph-client.radosgw.0.log; echo " ----- Compress info -----"; gzip -l -v ceph-client.radosgw.0.log.gz; echo "----- Uncompress -----"; time gzip -d -f ceph-client.radosgw.0.log.gz; done
测试过程
gzip 压缩与解压缩
root@node244:/mnt/disk/compress_test# for i in {1..9}; do echo "============================ Compress Level $i ==========================="; echo " ----- Compress -----"; time gzip -k -f -$i ceph-client.radosgw.0.log; echo " ----- Compress info -----"; gzip -l -v ceph-client.radosgw.0.log.gz; echo "----- Uncompress -----"; time gzip -d -f ceph-client.radosgw.0.log.gz; done
============================ Compress Level 1 ===========================
----- Compress -----
real 0m3.389s
user 0m3.261s
sys 0m0.128s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 27542300 571073631 95.2% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.502s
user 0m1.962s
sys 0m0.472s
============================ Compress Level 2 ===========================
----- Compress -----
real 0m3.385s
user 0m3.257s
sys 0m0.128s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 27158636 571073631 95.2% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.782s
user 0m1.893s
sys 0m0.444s
============================ Compress Level 3 ===========================
----- Compress -----
real 0m3.407s
user 0m3.262s
sys 0m0.144s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 26820084 571073631 95.3% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.403s
user 0m1.919s
sys 0m0.417s
============================ Compress Level 4 ===========================
----- Compress -----
real 0m4.302s
user 0m4.150s
sys 0m0.152s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 22196434 571073631 96.1% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.413s
user 0m1.914s
sys 0m0.433s
============================ Compress Level 5 ===========================
----- Compress -----
real 0m4.385s
user 0m4.237s
sys 0m0.149s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 20643438 571073631 96.4% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.370s
user 0m1.937s
sys 0m0.349s
============================ Compress Level 6 ===========================
----- Compress -----
real 0m5.298s
user 0m5.142s
sys 0m0.156s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 19503464 571073631 96.6% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.367s
user 0m1.910s
sys 0m0.400s
============================ Compress Level 7 ===========================
----- Compress -----
real 0m5.518s
user 0m5.402s
sys 0m0.116s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 19396724 571073631 96.6% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.435s
user 0m1.842s
sys 0m0.486s
============================ Compress Level 8 ===========================
----- Compress -----
real 0m6.961s
user 0m6.853s
sys 0m0.108s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 18411146 571073631 96.8% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.480s
user 0m1.884s
sys 0m0.399s
============================ Compress Level 9 ===========================
----- Compress -----
real 0m7.233s
user 0m7.077s
sys 0m0.156s
----- Compress info -----
method crc date time compressed uncompressed ratio uncompressed_name
defla d30eafa2 Jun 3 10:33 18186392 571073631 96.8% ceph-client.radosgw.0.log
----- Uncompress -----
real 0m2.877s
user 0m1.820s
sys 0m0.456s
root@node244:/mnt/disk/compress_test#
bzip2的压缩与解压缩
root@node244:/mnt/disk/compress_test# for i in {1..9}; do echo "============================ Compress Level $i ==========================="; echo " ----- Compress -----"; time bzip2 -k -f -v -$i ceph-client.radosgw.0.log ceph-client.radosgw.0.log.bz2; echo "----- Uncompress -----"; time bzip2 -d -f ceph-client.radosgw.0.log.bz2; done
============================ Compress Level 1 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 28.266:1, 0.283 bits/byte, 96.46% saved, 571073631 in, 20203523 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 1m14.986s
user 1m14.115s
sys 0m0.212s
----- Uncompress -----
real 0m8.986s
user 0m7.820s
sys 0m0.492s
============================ Compress Level 2 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 34.344:1, 0.233 bits/byte, 97.09% saved, 571073631 in, 16627875 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 1m26.956s
user 1m25.741s
sys 0m0.232s
----- Uncompress -----
real 0m8.858s
user 0m8.241s
sys 0m0.488s
============================ Compress Level 3 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 37.331:1, 0.214 bits/byte, 97.32% saved, 571073631 in, 15297380 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 1m35.014s
user 1m34.232s
sys 0m0.140s
----- Uncompress -----
real 0m9.019s
user 0m8.451s
sys 0m0.512s
============================ Compress Level 4 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 38.943:1, 0.205 bits/byte, 97.43% saved, 571073631 in, 14664242 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 1m41.031s
user 1m40.805s
sys 0m0.160s
----- Uncompress -----
real 0m9.702s
user 0m8.491s
sys 0m0.596s
============================ Compress Level 5 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 40.177:1, 0.199 bits/byte, 97.51% saved, 571073631 in, 14214101 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 1m46.857s
user 1m46.109s
sys 0m0.172s
----- Uncompress -----
real 0m9.378s
user 0m8.565s
sys 0m0.536s
============================ Compress Level 6 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 41.332:1, 0.194 bits/byte, 97.58% saved, 571073631 in, 13816797 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 1m50.821s
user 1m50.619s
sys 0m0.196s
----- Uncompress -----
real 0m9.688s
user 0m8.611s
sys 0m0.556s
============================ Compress Level 7 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 41.987:1, 0.191 bits/byte, 97.62% saved, 571073631 in, 13601242 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 1m55.011s
user 1m54.842s
sys 0m0.168s
----- Uncompress -----
real 0m9.197s
user 0m8.560s
sys 0m0.575s
============================ Compress Level 8 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 42.637:1, 0.188 bits/byte, 97.65% saved, 571073631 in, 13393739 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 2m0.052s
user 1m59.319s
sys 0m0.100s
----- Uncompress -----
real 0m9.232s
user 0m8.650s
sys 0m0.516s
============================ Compress Level 9 ===========================
----- Compress -----
ceph-client.radosgw.0.log: 43.064:1, 0.186 bits/byte, 97.68% saved, 571073631 in, 13261043 out.
bzip2: Input file ceph-client.radosgw.0.log.bz2 already has .bz2 suffix.
real 2m1.284s
user 2m1.072s
sys 0m0.204s
----- Uncompress -----
real 0m9.246s
user 0m8.667s
sys 0m0.512s
root@node244:/mnt/disk/compress_test#
pbzip2的压缩与解压缩
由于担心不同CPU并发影响测试效果，这里指定了CPU个数为24个，在不带-p参数情况下，默认32个，当前环境虽然有32cores，但并不是每次都能全部参与，有时候是32，有时候是29，有时候是26，所以这里指定一个更低值，确保每次执行都使用相同cores的CPU数。
@node244:/mnt/disk/compress_test# for i in {1..9}; do echo "============================ Compress Level $i ==========================="; echo " ----- Compress -----"; time pbzip2 -k -f -v -p24 -$i ceph-client.radosgw.0.log; echo "----- Uncompress -----"; time pbzip2 -p24 -d -f ceph-client.radosgw.0.log.bz2; done
============================ Compress Level 1 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 100 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 20251314 bytes
-------------------------------------------
Wall Clock: 5.553146 seconds
real 0m5.557s
user 2m10.868s
sys 0m0.600s
----- Uncompress -----
real 0m0.675s
user 0m11.626s
sys 0m0.710s
============================ Compress Level 2 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 200 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 17034671 bytes
-------------------------------------------
Wall Clock: 6.295284 seconds
real 0m6.299s
user 2m28.521s
sys 0m0.892s
----- Uncompress -----
real 0m0.706s
user 0m12.163s
sys 0m0.780s
============================ Compress Level 3 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 300 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 15336308 bytes
-------------------------------------------
Wall Clock: 7.094542 seconds
real 0m7.098s
user 2m46.324s
sys 0m1.328s
----- Uncompress -----
real 0m1.047s
user 0m12.899s
sys 0m0.723s
============================ Compress Level 4 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 400 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 15289111 bytes
-------------------------------------------
Wall Clock: 7.390034 seconds
real 0m7.393s
user 2m53.305s
sys 0m1.428s
----- Uncompress -----
real 0m0.738s
user 0m13.124s
sys 0m0.806s
============================ Compress Level 5 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 500 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 14424635 bytes
-------------------------------------------
Wall Clock: 7.929576 seconds
real 0m7.933s
user 3m5.904s
sys 0m1.616s
----- Uncompress -----
real 0m0.783s
user 0m14.003s
sys 0m0.780s
============================ Compress Level 6 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 600 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 14320561 bytes
-------------------------------------------
Wall Clock: 8.235693 seconds
real 0m8.240s
user 3m12.339s
sys 0m2.512s
----- Uncompress -----
real 0m0.770s
user 0m13.975s
sys 0m0.789s
============================ Compress Level 7 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 700 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 14284009 bytes
-------------------------------------------
Wall Clock: 8.463171 seconds
real 0m8.467s
user 3m17.862s
sys 0m2.209s
----- Uncompress -----
real 0m0.828s
user 0m14.793s
sys 0m0.932s
============================ Compress Level 8 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 800 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 14161949 bytes
-------------------------------------------
Wall Clock: 9.343830 seconds
real 0m9.348s
user 3m37.798s
sys 0m3.541s
----- Uncompress -----
real 0m0.844s
user 0m15.348s
sys 0m0.937s
============================ Compress Level 9 ===========================
----- Compress -----
Parallel BZIP2 v1.1.9 - by: Jeff Gilchrist [http://compression.ca]
[Apr. 13, 2014] (uses libbzip2 by Julian Seward)
Major contributions: Yavor Nikolov <nikolov.javor+pbzip2@gmail.com>
# CPUs: 24
BWT Block Size: 900 KB
File Block Size: 900 KB
Maximum Memory: 100 MB
-------------------------------------------
File #: 1 of 1
Input Name: ceph-client.radosgw.0.log
Output Name: ceph-client.radosgw.0.log.bz2
Input Size: 571073631 bytes
Compressing data...
Output Size: 13295516 bytes
-------------------------------------------
Wall Clock: 10.434447 seconds
real 0m10.438s
user 4m3.675s
sys 0m4.175s
----- Uncompress -----
real 0m0.796s
user 0m15.991s
sys 0m0.911s
root@node244:/mnt/disk/compress_test#
xz的压缩与解压缩
root@node244:/mnt/disk/compress_test# for i in {0..9}; do echo "============================ Compress Level $i ==========================="; echo " ----- Compress -----"; rm -rf *.xz; time xz -k -f -v -$i ceph-client.radosgw.0.log; echo " ----- Compress info -----"; xz -l -v ceph-client.radosgw.0.log.xz; echo "----- Uncompress -----"; time xz -d -f ceph-client.radosgw.0.log.xz; done
============================ Compress Level 0 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 17.9 MiB / 544.6 MiB = 0.033 71 MiB/s 0:07
real 0m7.703s
user 0m7.567s
sys 0m0.136s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 17.9 MiB (18,732,968 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.033
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 18,732,968 571,073,631 0.033 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 18,732,928 571,073,631 0.033 CRC64
----- Uncompress -----
real 0m2.886s
user 0m1.895s
sys 0m0.444s
============================ Compress Level 1 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 17.2 MiB / 544.6 MiB = 0.032 56 MiB/s 0:09
real 0m9.666s
user 0m9.514s
sys 0m0.152s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 17.2 MiB (18,010,756 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.032
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 18,010,756 571,073,631 0.032 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 18,010,716 571,073,631 0.032 CRC64
----- Uncompress -----
real 0m2.282s
user 0m1.719s
sys 0m0.496s
============================ Compress Level 2 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 16.3 MiB / 544.6 MiB = 0.030 45 MiB/s 0:12
real 0m12.128s
user 0m11.964s
sys 0m0.164s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 16.3 MiB (17,065,980 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.030
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 17,065,980 571,073,631 0.030 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 17,065,940 571,073,631 0.030 CRC64
----- Uncompress -----
real 0m2.277s
user 0m1.694s
sys 0m0.517s
============================ Compress Level 3 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 16.1 MiB / 544.6 MiB = 0.030 32 MiB/s 0:16
real 0m16.986s
user 0m16.778s
sys 0m0.208s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 16.1 MiB (16,899,448 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.030
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 16,899,448 571,073,631 0.030 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 16,899,408 571,073,631 0.030 CRC64
----- Uncompress -----
real 0m2.252s
user 0m1.664s
sys 0m0.532s
============================ Compress Level 4 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 16.4 MiB / 544.6 MiB = 0.030 17 MiB/s 0:31
real 0m31.449s
user 0m31.220s
sys 0m0.228s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 16.4 MiB (17,154,260 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.030
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 17,154,260 571,073,631 0.030 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 17,154,220 571,073,631 0.030 CRC64
----- Uncompress -----
real 0m2.349s
user 0m1.868s
sys 0m0.412s
============================ Compress Level 5 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 15.6 MiB / 544.6 MiB = 0.029 12 MiB/s 0:45
real 0m45.585s
user 0m45.152s
sys 0m0.420s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 15.6 MiB (16,360,932 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.029
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 16,360,932 571,073,631 0.029 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 16,360,892 571,073,631 0.029 CRC64
----- Uncompress -----
real 0m2.398s
user 0m1.851s
sys 0m0.488s
============================ Compress Level 6 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 15.1 MiB / 544.6 MiB = 0.028 7.1 MiB/s 1:17
real 1m17.152s
user 1m16.763s
sys 0m0.388s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 15.1 MiB (15,786,352 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.028
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 15,786,352 571,073,631 0.028 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 15,786,312 571,073,631 0.028 CRC64
----- Uncompress -----
real 0m2.302s
user 0m1.752s
sys 0m0.487s
============================ Compress Level 7 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 15.1 MiB / 544.6 MiB = 0.028 6.7 MiB/s 1:20
real 1m20.962s
user 1m20.478s
sys 0m0.460s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 15.1 MiB (15,862,848 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.028
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 15,862,848 571,073,631 0.028 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 15,862,808 571,073,631 0.028 CRC64
----- Uncompress -----
real 0m2.368s
user 0m1.803s
sys 0m0.497s
============================ Compress Level 8 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 15.4 MiB / 544.6 MiB = 0.028 6.4 MiB/s 1:25
real 1m25.153s
user 1m24.488s
sys 0m0.660s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 15.4 MiB (16,130,916 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.028
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 16,130,916 571,073,631 0.028 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 16,130,876 571,073,631 0.028 CRC64
----- Uncompress -----
real 0m2.359s
user 0m1.768s
sys 0m0.535s
============================ Compress Level 9 ===========================
----- Compress -----
ceph-client.radosgw.0.log (1/1)
100 % 15.7 MiB / 544.6 MiB = 0.029 5.9 MiB/s 1:32
real 1m32.645s
user 1m31.211s
sys 0m1.424s
----- Compress info -----
ceph-client.radosgw.0.log.xz (1/1)
Streams: 1
Blocks: 1
Compressed size: 15.7 MiB (16,510,384 B)
Uncompressed size: 544.6 MiB (571,073,631 B)
Ratio: 0.029
Check: CRC64
Stream padding: 0 B
Streams:
Stream Blocks CompOffset UncompOffset CompSize UncompSize Ratio Check Padding
1 1 0 0 16,510,384 571,073,631 0.029 CRC64 0
Blocks:
Stream Block CompOffset UncompOffset TotalSize UncompSize Ratio Check
1 1 12 0 16,510,344 571,073,631 0.029 CRC64
----- Uncompress -----
real 0m2.394s
user 0m1.763s
sys 0m0.500s
root@node244:/mnt/disk/compress_test#
测试结果
Compression Size
Unit:bytes
| Compress Level | gzip | bzip2 | pbzip2 | xz |
|---|---|---|---|---|
| 0 | - | - | - | 18,732,968 |
| 1 | 27542300 | 20203523 | 20251314 | 18,010,756 |
| 2 | 27158636 | 16627875 | 17034671 | 17,065,980 |
| 3 | 26820084 | 15297380 | 15336308 | 16,899,448 |
| 4 | 22196434 | 14664242 | 15289111 | 17,154,260 |
| 5 | 20643438 | 14214101 | 14424635 | 16,360,932 |
| 6 | 19503464 | 13816797 | 14320561 | 15,786,352 |
| 7 | 19396724 | 13601242 | 14284009 | 15,862,848 |
| 8 | 18411146 | 13393739 | 14161949 | 16,130,916 |
| 9 | 18186392 | 13261043 | 13295516 | 16,510,384 |
Compression Time
先从压缩时间开始，下列图表显示了从1到9的每个压缩级别完成压缩所花费的时间。
Unit: seconds
| Compress Level | gzip | bzip2 | pbzip2 | xz |
|---|---|---|---|---|
| 0 | - | - | - | 0m7.703s |
| 1 | 0m3.389s | 1m14.986s | 0m5.557s | 0m9.666s |
| 2 | 0m3.385s | 1m26.956s | 0m6.299s | 0m12.128s |
| 3 | 0m3.407s | 1m35.014s | 0m7.098s | 0m16.986s |
| 4 | 0m4.302s | 1m41.031s | 0m7.393s | 0m31.449s |
| 5 | 0m4.385s | 1m46.857s | 0m7.933s | 0m45.585s |
| 6 | 0m5.298s | 1m50.821s | 0m8.240s | 1m17.152s |
| 7 | 0m5.518s | 1m55.011s | 0m8.467s | 1m20.962s |
| 8 | 0m6.961s | 2m0.052s | 0m9.348s | 1m25.153s |
| 9 | 0m7.233s | 2m1.284s | 0m10.438s | 1m32.645s |
从折线图可以看出，随着压缩级别的提高，bzip2需要花费更长的时间才能完成，pbzip2和gzip的变化不大，而压缩级别为3后，xz的增长非常明显。
Compression Ratio
Unit: %
| Compress Level | gzip | bzip2 | pbzip2 | xz |
|---|---|---|---|---|
| 0 | - | - | - | 3.3 |
| 1 | 4.8 | 3.54 | 3.55 | 3.3 |
| 2 | 4.8 | 2.91 | 2.98 | 3.0 |
| 3 | 4.7 | 2.68 | 2.69 | 3.0 |
| 4 | 3.9 | 2.57 | 2.68 | 3.0 |
| 5 | 3.6 | 2.49 | 2.53 | 2.9 |
| 6 | 3.4 | 2.42 | 2.51 | 2.8 |
| 7 | 3.4 | 2.38 | 2.50 | 2.8 |
| 8 | 3.2 | 2.35 | 2.48 | 2.8 |
| 9 | 3.2 | 2.32 | 2.33 | 2.9 |
compression ratio，越小越好，比如说源文件大小是100MiB，ratio为5%，则压缩后文件大小为5MiB。
从折线图看到趋势是：压缩级别越高，压缩率越低，说明文件被压缩的更小了。在这种情况下，xz始终提供比较平稳的压缩率（但从压缩时间图所示，xz在压缩级别3之后花费更长的时间才能获得这个效果），紧跟其后的是pbzip2和bzip2，gzip在压缩级别为3后，压缩率有所下降。
Compression Speed
Unit:MiB/s
| Compress Level | gzip | bzip2 | pbzip2 | xz |
|---|---|---|---|---|
| 0 | - | - | - | 70.702 |
| 1 | 160.702 | 7.263 | 98.006 | 56.344 |
| 2 | 160.892 | 6.263 | 86.461 | 44.906 |
| 3 | 159.853 | 5.732 | 76.728 | 32.063 |
| 4 | 126.597 | 5.391 | 73.667 | 17.318 |
| 5 | 124.200 | 5.097 | 68.652 | 11.947 |
| 6 | 102.797 | 4.914 | 66.094 | 7.059 |
| 7 | 98.698 | 4.735 | 64.322 | 6.727 |
| 8 | 78.239 | 4.536 | 58.260 | 6.396 |
| 9 | 75.296 | 4.490 | 52.176 | 5.879 |
Decompression Time
Unit: seconds
| Decompress Level | gzip | bzip2 | pbzip2 | xz |
|---|---|---|---|---|
| 0 | - | - | - | 0m2.886s |
| 1 | 0m2.502s | 0m8.986s | 0m0.675s | 0m2.282s |
| 2 | 0m2.782s | 0m8.858s | 0m0.706s | 0m2.277s |
| 3 | 0m2.403s | 0m9.019s | 0m1.047s | 0m2.252s |
| 4 | 0m2.413s | 0m9.702s | 0m0.738s | 0m2.349s |
| 5 | 0m2.370s | 0m9.378s | 0m0.783s | 0m2.398s |
| 6 | 0m2.367s | 0m9.688s | 0m0.770s | 0m2.302s |
| 7 | 0m2.435s | 0m9.197s | 0m0.828s | 0m2.368s |
| 8 | 0m2.480s | 0m9.232s | 0m0.844s | 0m2.359s |
| 9 | 0m2.877s | 0m9.246s | 0m0.796s | 0m2.394s |
由于数值比较小，从折线图上直接看不出什么效果，从表格中可以看出，当文件的压缩级别越高，解压相应的压缩文件耗时越低。xz的解压缩时间几乎是一条直线，非常平稳，gbip2次之，当gbzip2解压比xz更快。
从Compression time, Compression Ratio，结合当前的Decompress Time看，总体上推荐gbzip2进行文件的压缩与解压缩操作。
Decompression Speed
Unit: MiB/s
| Decompress Level | gzip | bzip2 | pbzip2 | xz |
|---|---|---|---|---|
| 0 | - | - | - | 6.202 |
| 1 | 10.498 | 2.144 | 28.612 | 7.537 |
| 2 | 9.310 | 1.790 | 23.011 | 7.159 |
| 3 | 10.644 | 1.618 | 13.970 | 7.149 |
| 4 | 8.773 | 1.441 | 19.757 | 6.982 |
| 5 | 8.307 | 1.445 | 17.569 | 6.505 |
| 6 | 7.858 | 1.360 | 17.737 | 6.560 |
| 7 | 7.598 | 1.410 | 16.452 | 6.558 |
| 8 | 7.080 | 1.384 | 16.002 | 6.528 |
| 9 | 6.028 | 1.368 | 15.929 | 6.558 |
性能差异和比较
默认情况下，当未指定压缩级别时，gzip 使用 -6，bzip2 和 pbzip2 使用 -9，xz 使用 -6。
根据测试结果，原因非常明确：对于 gzip 和 xz -6 作为默认压缩方法提供良好的压缩级别，但完成时间不会太长，损失一个平衡点，因为较高的压缩级别需要更长的时间来处理压缩。另一方面，pbzip2 最好使用默认压缩级别为 9，如手册页中建议的那样，此处的结果证实了这一点，压缩比增加，但所采用的时间几乎相同，在级别 1 到 9 之间相差不到一秒；但反观bzip2，使用不同的压缩级别，压缩耗时还是有蛮大幅度变化的。
一般来说，xz 达到最佳压缩级别，非常的平稳，然后是 bzip2和pbzip2，然后是 gzip。为了达到更好的压缩，但是xz通常需要最长的完成，其次是pbzip2，然后是gzip，最差的是bzip2，耗时太久。
xz 的默认压缩级别为 6，而 pbzip2 在压缩级别 9 时仅花费比 gzip 稍长一点的时间，并且压缩量更好，而 pbzip2 和 xz 之间的差异小于 pbzip2 和 gzip 之间的差异，因此 pbzip2 成为压缩的优先选择。
根据这些测试结果，pbzip2是压缩的良好中间地带，gzip只是压缩的更快一点，而xz可能并不真正值得使用，尤其使用更高的文件压缩级别（>=6），因为它需要更长的时间来完成压缩操作。
然而，使用 bzip2 解压缩比 xz 或 gzip 或 pbzip2 需要更长的时间，xz 处于解压缩文件的良好中间地带，而 gbzip2 则是解压缩最快的。
选择哪种压缩方式？
那么我该选择哪种压缩/解压缩方式？这完全取决于应用目的了，需要因地制宜选择所需的压缩/解压缩方法。
-
如果是交互式的压缩文件，可以使用pxz，这个指令可以看到压缩进度；
-
如果只是想尽可能快的压缩和解压缩文件，很少考虑压缩比情况下，gzip是一个很好的选择；
-
如果只想要一个更好的压缩比，以节约磁盘空间，并愿意话费更多的时间去加压缩它，那么xz只比较好的选择，其次是pbzip2