当前位置:网站首页>How much faster is a server equipped with a SSD than a mechanical hard disk
How much faster is a server equipped with a SSD than a mechanical hard disk
2020-11-08 16:17:00 【Zhang Yanfei Allen】
I believe you all know that SSD (SSD) The advantage of this is that it is faster than the traditional mechanical hard disk (HDD) Be quick , So now more and more solid-state drives appear in online servers . But as a development that cares about performance numbers , I want to be more precise about carrying SSD The server is in IO The performance is better than that of carrying HDD How much faster , The order IO How much faster in the case of , Random IO How much faster under the circumstances ? Finally, I took time to do a performance test recently .
Test environment
I found two servers , The disks are all Raid array , They are carrying SSD and HDD, More detailed configuration is as follows :
- HDD Real machine :
- Raid The card model is PERC H730 Mini,1GB RAM cache
- 4 block 500GB SSD Composed of raid5, Available capacity 1.3T
- SSD Real machine :
- Raid The card model is the same as above
- 7 block 300G HDD The hard disk makes up Raid5, Available capacity 1.6T
Okay , The contestants are in position , Then select the pressure measuring tool fio. Designated ratio ( Pressure ) " ( measuring ) gauge ( ginseng ) be ( Count ) as follows :
- IO engine : In order to put enough pressure on the hard disk , Choose asynchronous mode libaio
- PageCache: In order to get closer to the performance of the disk itself , Turn on Direct Parameters bypass Linux System memory cache
- Pressure test object : On the safe side , No naked device used , The files used
- file size :100GB, Because of my Raid The card cache is 1G, The guarantee is much bigger than the cache
- Scheduling strategy : Choose common noop
The contrast test officially began .
Sequential read PK
Let's start with a test under sequential access , Because in this environment, whether it's a mechanical hard disk , Or a solid-state drive , Performance will be optimal .IO Size from 512K Until 1M.
Let's take a look at the mechanical hard disk :
Under SSD :
The data looks like , In order IO Under the circumstances , Actually, it carries HDD Server for IO Performance is not being carried ssd It's falling too much . This is because
- The order IO Under the circumstances ,RAID The card has a high hit rate , Especially when it's set up RAID Prefetch
- In its own order IO It's also the best state of mechanical disk work
therefore , Modern in the field of servers ,SSD It's just that there are more and more applications , But it doesn't replace HDD. One of the reasons is because of the order of the mechanical hard disks IO It's not slow , Plus Raid Blessing , So there's a big market share . After comparing the order IO, Let's compare another application scenario , Random IO.
Random reads PK
Remember the beginning fio In the pressure measurement parameters, we put Page Cache It's disabled , Plus the size of the test file is 100GB, This is much more than Raid The cache size of the card . So random based on this premise IO, All levels of cache are basically out of use ,IO Performance speed depends entirely on the hard disk itself .
stay 《 Mechanical hard disk random IO Slower than you think 》 in , We look at the random of mechanical hard disks IO It's really bad performance .
Let's look at carrying SSD Server for IO performance :
By contrast , Mechanical hard disk random IO It's not that slow , We choose the most recognized result of the above 4K IO size Look at .
- From a bandwidth perspective , Only less than 1M The throughput of ,
- From the perspective of delay , stay 4.4ms about
Let's look at the SSD 4K IO Size Next performance . And under the same conditions SSD Can have 32M.
- From a bandwidth perspective , There are still 32M, Than HDD It can be dozens of times faster
- From the perspective of delay , about 120us about . Than HDD, Namely 4400:120, It's also dozens of times higher
summary
In order IO Under the circumstances , Because there is Raid The blessing of card cache , be based on HDD Composed of Raid The array server is in IO The performance is not too bad . But in a random read scenario , Whether bandwidth or latency metrics ,SSD It's better than HDD More than ten times faster . So in the server application SSD, The main solution is random IO The problem of . So if you have too many Page Cache,Raid Card cache can't hold random IO request , Then please put HDD Replace it with SSD Well .
Development of hard disk album of internal training :
- 1. Disk opening : Take off the hard coat of the mechanical hard disk !
- 2. Disk partitioning also implies technical skills
- 3. How can we solve the problem that mechanical hard disks are slow and easy to break down ?
- 4. Disassemble the SSD structure
- 5. How much disk space does a new empty file take ?
- 6. Only 1 How much disk space does a byte file actually take up
- 7. When there are too many documents ls Why is the command stuck ?
- 8. Understand the principle of formatting
- 9.read How much disk does a byte of file actually take place on IO?
- 10.write When to write to disk after one byte of file IO?
- 11. Mechanical hard disk random IO Slower than you think
- 12. How much faster is a server equipped with a SSD than a mechanical hard disk ?
My official account is 「 Develop internal skill and practice 」, I'm not just talking about technical theory here , It's not just about practical experience . It's about combining theory with practice , Deepen the understanding of theory with practice 、 Use theory to improve your technical practice ability . Welcome to my official account , Please also share with your friends ~~~
版权声明
本文为[Zhang Yanfei Allen]所创,转载请带上原文链接,感谢
边栏推荐
- Mac环境安装Composer
- Rabbitmq (1) - basic introduction
- .NET 大数据量并发解决方案
- Interpretation of deepmind's latest paper: the causal reasoning algorithm in discrete probability tree is proposed for the first time
- Framework - SPI four modes + general device driver implementation - source code
- Arduino IDE搭建ESP8266开发环境,文件下载过慢解决方法 | ESP-01制作WiFi开关教程,改造宿舍灯
- Jsliang job series - 07 - promise
- Recurrence of Apache kylin Remote Code Execution Vulnerability (cve-2020-1956)
- Google's AI model, which can translate 101 languages, is only one more than Facebook
- SQL 速查
猜你喜欢
Liteos message queuing
重返全球第三,小米做对了什么?
技术总监7年总结,如何进行正确的沟通?
Huawei has an absolute advantage in the 5g mobile phone market, and the market share of Xiaomi is divided by the market survey organization
机械硬盘随机IO慢的超乎你的想象
构建者模式(Builder pattern)
How to make a correct summary for 7 years?
uni-app实战仿微信app开发
Build simple business monitoring Kanban based on Alibaba cloud log service
别再在finally里面释放资源了,解锁个新姿势!
随机推荐
漫画:寻找股票买入卖出的最佳时机(整合版)
c++ opencv4.3 sift匹配
RestfulApi 学习笔记——父子资源(四)
聊聊Go代码覆盖率技术与最佳实践
阿里云加速增长,进一步巩固领先优势
Hello world of rabbitmq
打工人,打工魂,抽终身会员,成为人上人!
Do these mistakes in your resume affect your annual salary of one million?
“他,程序猿,35岁,被劝退”:不要只懂代码,会说话,胜过10倍默默努力
Elasticsearch 学习一(基础入门).
On the concurrency of update operation
新型存算一体芯片诞生,利好人工智能应用~
Framework - SPI four modes + general device driver implementation - source code
Returning to the third place in the world, what did Xiaomi do right?
机械硬盘随机IO慢的超乎你的想象
Design by contract (DBC) and its application in C language
Mac环境安装Composer
How to make a correct summary for 7 years?
我用 Python 找出了删除我微信的所有人并将他们自动化删除了
Summary of template engine