Category: VMWare

VMware ESXi 和 vCSA 的MD5

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ESXi 7.0U2a

VMware vSphere Hypervisor (ESXi ISO) image
2021-04-29 | 7.0U2a | 390.11 MB | iso

Boot your server with this image in order to install or upgrade to ESXi (ESXi requires 64-bit capable servers). This ESXi image includes VMware Tools.

MD5SUM(¹): 5491860344ce79fcf2ffec2e72b79245
SHA1SUM(¹): c1c03244b9aed6a5f40cc53752e4079969be9383
SHA256SUM(¹): 35d80d52dfca79f52eadd1c641e2f990371e834e98b3ef95914b7f950b42f629

vCSA  7.0U2a

VMware vCenter Server Appliance
2021-04-27 | 7.0U2a | 7.45 GB | iso

VMware vCenter Server Appliance ISO. It includes the UI and CLI installer for install\, upgrade and migration for VMware vCenter Server Appliance\, VMware vSphere Update Manager and Update Manager Download Service (UMDS).

MD5SUM(¹): 492ea215363dc9d67bb195437dc6edde
SHA1SUM(¹): 26c3e52a02b9144b026f8cf343d11d0dce125731
SHA256SUM(¹): f628e8ef6d785643a5ece512a852358f0d76432352960e2bb11319df2a5f8ea4

6.7 u3:

VMware vSphere Hypervisor (ESXi ISO) image (Includes VMware Tools)
2019-08-20 | 6.7.0U3 | 314.66 MB | iso

Boot your server with this image in order to install or upgrade to ESXi (ESXi requires 64-bit capable servers). This ESXi image includes VMware Tools.
VMware-VMvisor-Installer-6.7.0.update03-14320388.x86_64
MD5SUM(¹): cafb95ae04245eb3e93fed1602b0fd3b 
SHA1SUM(¹): 415f08313062d1f8d46162dc81a009dbdbc59b3b 
SHA256SUM(¹): fcbaa4cd952abd9e629fb131b8f46a949844405d8976372e7e5b55917623fbe0
VMware vCenter Server Appliance
2019-08-20 | 6.7.0U3 | 3.93 GB | iso

vCenter Server Appliance ISO. It includes the UI and CLI installer for install upgrade migration for VMware vCenter Server Appliance\, VMware Platform Services Controller\, VMware vSphere Update Manager and Update Manager Download Service (UMDS)

VMware-VCSA-all-6.7.0-14367737.iso
MD5SUM(¹): dff12f195347a61a45d3aee3278ebfca 
SHA1SUM(¹): 6989f3e17278545d77251c46152c4e08e1c32db4 
SHA256SUM(¹): d0bc2c26d6313a92323ac5f8cab8838324613e6762e3a749646bac6496d4d838

 

2019-10-24 | 6.7.0U3a | 3.92 GB | iso

vCenter Server Appliance ISO. It includes the UI and CLI installer for install\, upgrade\, migration for VMware vCenter Server Appliance\, VMware Platform Services Controller\, VMware vSphere Update Manager and Update Manager Download Service (UMDS).

VMware-VCSA-all-6.7.0-14836122.iso
MD5SUM(¹): bd986d69a66e24bbb6bd71c3c6ad4ac5 
SHA1SUM(¹): b97711529af60e475e1de644010162be3c9d92e3 
SHA256SUM(¹): ac817b8efbdfa6d1a40ea648f842621a7d14e37c8f5316f883ee4f1ccf61a6a5

vCSA Hardware Requirements

VMWare, , , , Leave a comment

在ESXi 6.7 上，使用vCSA 的话， tiny environment 是足够的. 但是在最新版本的vCSA 6.7中，总是会出现内存不足的warning。

经过一番google 知道了，VMWARE 在vCSA中主要使用的是Java，这是Java 的内存机制造成的，简单的解决办法就是直接增加vCSA 的内存. 在 ESXi 6.0 以后， vCSA 的内存是可以在VM 上直接更改的，这是很方便的事情。

另外如果服务器硬件足够，建议直接deploy 一个small 或者 medium environment 来直接解决这个问题。

下图是vCSA 的硬件需求，以后就不用每次都去翻官网了.

 

 

Small environment 都需要4 vCPU， 16 GB 的RAM，storage 也需要340GB， 最好是SSD

这个需求，说实话，真的比很多德利服务器的配置都高了。

不过幸好online.net, OVH 以及hetzner 这样的服务商的存在。。

推荐online.net 和OVH, 起码都是企业级的硬件和网络， hetzner 就要差点了

，

WebNX.com 服务器重新benchmark

Benchmark, VMWare, , Leave a comment

和online.net 一样，前面的测试有点不太规范，这次有机会重新测试一下

机器配置和online.net 一样， E5 1650V3， 64GB RAM， 2 X 1TB SSD ( micron 5100 enterprise SSD)

测试使用的程序是:

wget -qO- bench.sh | bash

直接测试IO，使用的是下面的commands:

dd if=/dev/zero of=test_$$ bs=64k count=16k conv=fdatasync && rm -f test_$$

直接在服务器裸机安装Centos 7，下面是测试结果:

[root@webnx ~]# hdparm -t /dev/sda

/dev/sda:
Timing buffered disk reads: 1422 MB in 3.00 seconds = 473.59 MB/sec
[root@webnx ~]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 1452 MB in 3.00 seconds = 483.80 MB/sec

[root@sda ~]# dd if=/dev/zero of=test_$$ bs=64k count=16k conv=fdatasync && rm -f test_$$
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 2.75682 s, 389 MB/s

测试了几次，都在390 MB/s 左右

[root@sdb]# dd if=/dev/zero of=test_$$ bs=64k count=16k conv=fdatasync && rm -f test_$$
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 2.75827 s, 389 MB/s

两块SSD 都是micron 的全新 1 TB SSD, 看来SSD 的速度就在400 MB/s 左右

用bench.sh的程序测试下:

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 12
CPU frequency : 1199.920 MHz
Total size of Disk : 851.3 GB (1.5 GB Used)
Total amount of Mem : 64316 MB (564 MB Used)
Total amount of Swap : 30516 MB (0 MB Used)
System uptime : 0 days, 0 hour 8 min
Load average : 0.08, 0.05, 0.03
OS : CentOS 7.7.1908
Arch : x86_64 (64 Bit)
Kernel : 3.10.0-1062.4.1.el7.x86_64
----------------------------------------------------------------------
I/O speed(1st run) : 391 MB/s
I/O speed(2nd run) : 388 MB/s
I/O speed(3rd run) : 389 MB/s
Average I/O speed : 389.3 MB/s
----------------------------------------------------------------------

依然在390MB/s左右， micron 的SSD的表现要差于intel 和 samsung的SSD

下面看看在ESXi 6.7 上使用native drive 的表现:

Centos 7 with LVM

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 4
CPU frequency : 3499.997 MHz
Total size of Disk : 27.0 GB (1.3 GB Used)
Total amount of Mem : 3950 MB (165 MB Used)
Total amount of Swap : 3071 MB (0 MB Used)
System uptime : 0 days, 0 hour 6 min
Load average : 0.16, 0.10, 0.06
OS : CentOS 7.6.1810
Arch : x86_64 (64 Bit)
Kernel : 3.10.0-957.el7.x86_64
----------------------------------------------------------------------
I/O speed(1st run) : 469 MB/s
I/O speed(2nd run) : 466 MB/s
I/O speed(3rd run) : 468 MB/s
Average I/O speed : 467.7 MB/s
----------------------------------

可以看到这个这个数据非常的好，基本接近原生SSD 的表现了

下面是Centos 7 without LVM

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 4
CPU frequency : 3499.997 MHz
Total size of Disk : 26.3 GB (2.3 GB Used)
Total amount of Mem : 3950 MB (150 MB Used)
Total amount of Swap : 3813 MB (0 MB Used)
System uptime : 0 days, 0 hour 1 min
Load average : 0.58, 0.23, 0.08
OS : CentOS 7.6.1810
Arch : x86_64 (64 Bit)
Kernel : 3.10.0-957.el7.x86_64
----------------------------------------------------------------------
I/O speed(1st run) : 458 MB/s
I/O speed(2nd run) : 457 MB/s
I/O speed(3rd run) : 460 MB/s
Average I/O speed : 458.3 MB/s

Centos 7 with LVM and standard partition mounted on /sata, 

----------------------------------------------------------------------
I/O speed(1st run) : 452 MB/s
I/O speed(2nd run) : 456 MB/s
I/O speed(3rd run) : 461 MB/s
Average I/O speed : 456.3 MB/s
----------------------------------------------------------------------

/data上， SSD 的IO 也会降速，需要很长一段时间才能恢复满速

在Debian上测试一下(无论LVM还是standard partition结果都一样)：

----------------------------------------------------------------------
----------------------------------------------------------------------
CPU model            : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores      : 4
CPU frequency        : 3499.997 MHz
Total size of Disk   : 94.2 GB (13.1 GB Used)
Total amount of Mem  : 4044 MB (129 MB Used)
Total amount of Swap : 4191 MB (0 MB Used)
System uptime        : 0 days, 0 hour 9 min
----------------------------------------------------------------------
CPU model            : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores      : 4
CPU frequency        : 3499.997 MHz
Total size of Disk   : 94.2 GB (13.1 GB Used)
Total amount of Mem  : 4044 MB (129 MB Used)
Total amount of Swap : 4191 MB (0 MB Used)
System uptime        : 0 days, 0 hour 15 min
Load average         : 0.02, 0.13, 0.14
OS                   : Debian GNU/Linux 10
Arch                 : x86_64 (64 Bit)
Kernel               : 4.19.0-6-amd64
----------------------------------------------------------------------
I/O speed(1st run)   : 456 MB/s
I/O speed(2nd run)   : 457 MB/s
I/O speed(3rd run)   : 462 MB/s
Average I/O speed    : 458.3 MB/s
----------------------------------------------------------------------
Node Name                       IPv4 address            Download Speed
CacheFly                        205.234.175.175         109MB/s
Linode, Tokyo2, JP              139.162.65.37           22.3MB/s
Linode, Singapore, SG           139.162.23.4
Linode, London, UK              176.58.107.39           16.4MB/s
Linode, Frankfurt, DE           139.162.130.8           15.1MB/s
Linode, Fremont, CA             50.116.14.9             74.5MB/s
Softlayer, Dallas, TX           173.192.68.18           51.5MB/s
Softlayer, Seattle, WA          67.228.112.250          57.1MB/s
Softlayer, Frankfurt, DE        159.122.69.4            14.0MB/s
Softlayer, Singapore, SG        119.81.28.170           10.8MB/s
Softlayer, HongKong, CN         119.81.130.170          12.7MB/s
----------------------------------------------------------------------
----------------------------------------------------------------------

在Debian上，有的时候速度会降到200MB/s, 但是需要很长一段时间来恢复

下面来看看回退ssd 的driver 以后的表现:

回退driver以后，Debian 10 with LVM or without LVM

----------------------------------------------------------------------
CPU model            : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores      : 4
CPU frequency        : 3499.997 MHz
Total size of Disk   : 94.2 GB (13.1 GB Used)
Total amount of Mem  : 4044 MB (142 MB Used)
Total amount of Swap : 4191 MB (0 MB Used)
System uptime        : 0 days, 12 hour 13 min
Load average         : 0.00, 0.00, 0.00
OS                   : Debian GNU/Linux 10
Arch                 : x86_64 (64 Bit)
Kernel               : 4.19.0-6-amd64
----------------------------------------------------------------------
I/O speed(1st run)   : 456 MB/s
I/O speed(2nd run)   : 461 MB/s
I/O speed(3rd run)   : 459 MB/s
Average I/O speed    : 458.7 MB/s

在测试中发现，SSD在standard partition上会降速，降速到200MB/s以后，会花费很长一段时间恢复到满速460MB/s, 但是在centos 7下，这个恢复是很快的

Centos 7 Standard Partition:

----------------------------------------------------------------------
I/O speed(1st run) : 455 MB/s
I/O speed(2nd run) : 457 MB/s
I/O speed(3rd run) : 457 MB/s
Average I/O speed : 456.3 MB/s
----------------------------------------------------------------------

Centos 7 with LVM:

----------------------------------------------------------------------
I/O speed(1st run) : 464 MB/s
I/O speed(2nd run) : 466 MB/s
I/O speed(3rd run) : 462 MB/s
Average I/O speed : 464.0 MB/s
----------------------------------------------------------------------

Centos 7 LVM with standard partition mounted on /data

----------------------------------------------------------------------
I/O speed(1st run) : 456 MB/s
I/O speed(2nd run) : 461 MB/s
I/O speed(3rd run) : 458 MB/s
Average I/O speed : 458.3 MB/s
----------------------------------------------------------------------

在测试中发现，即使会有短暂的降速到200MB/s, 也会很快的恢复到460MB/s 的满速

通过以上的测试可以看到，vmware 全新的native driver，基本上解决了micron ssd 的low IO performance 的问题

micron 的ssd 偶尔会降速到200 MB/s，但是基本是可以恢复满速的，只是时间有长有短的问题。

Online.net Pro-4-L 重新benchmark

Benchmark, VMWareLeave a comment

前面的测试有点不太规范，这次又机会重新测试一下。

机器配置是Xeon E5 1650V3, 96GB RAM, 3X500GB SSD

测试使用的程序是:

wget -qO- bench.sh | bash

直接测试IO，使用的是下面的commands:

dd if=/dev/zero of=test_$$ bs=64k count=16k conv=fdatasync && rm -f test_$$

直接在服务器裸机上安装Centos 7， 下面是测试结果:

[root@sd ~]# hdparm -t /dev/sda

/dev/sda:
Timing buffered disk reads: 1454 MB in 3.00 seconds = 484.53 MB/sec

[root@sd ~]# hdparm -t /dev/sdb

/dev/sdb:
Timing buffered disk reads: 1472 MB in 3.00 seconds = 490.04 MB/sec

[root@sd ~]# hdparm -t /dev/sdc

/dev/sdc:
iming buffered disk reads: 1470 MB in 3.00 seconds = 489.96 MB/sec
[root@sd sda~]# dd if=/dev/zero of=test_$$ bs=64k count=16k conv=fdatasync && rm -f test_$$
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 2.65959 s, 404 MB/s

测试了几次，都在400 MB/s 左右

[root@sd sdb]# dd if=/dev/zero of=test_$$ bs=64k count=16k conv=fdatasync && rm -f test_$$
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 2.69217 s, 399 MB/s
[root@sd sdc]# dd if=/dev/zero of=test_$$ bs=64k count=16k conv=fdatasync && rm -f test_$$
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 2.70218 s, 397 MB/s

可以看到裸机直接测试的话，SSD 的IO 一般就在400 MB/s 左右

在Host上安装上Esxi 6.7 以后，分别测试Debian 9 和 Debian 10

Debian 9 测试结果:

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 8
CPU frequency : 3495.142 MHz
Total size of Disk : 55.0 GB (0.9 GB Used)
Total amount of Mem : 3907 MB (92 MB Used)
Total amount of Swap : 4045 MB (0 MB Used)
System uptime : 0 days, 0 hour 11 min
Load average : 0.96, 0.28, 0.09
OS : Debian GNU/Linux 9
Arch : x86_64 (64 Bit)
Kernel : 4.9.0-9-amd64
----------------------------------------------------------------------
I/O speed(1st run) : 82.2 MB/s
I/O speed(2nd run) : 79.9 MB/s
I/O speed(3rd run) : 80.1 MB/s
Average I/O speed : 80.7 MB/s

Debian 10 测试结果:

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 8
CPU frequency : 3495.951 MHz
Total size of Disk : 55.0 GB (1.0 GB Used)
Total amount of Mem : 3897 MB (150 MB Used)
Total amount of Swap : 4045 MB (0 MB Used)
System uptime : 0 days, 0 hour 25 min
Load average : 1.14, 0.31, 0.11
OS : Debian GNU/Linux 10
Arch : x86_64 (64 Bit)
Kernel : 4.19.0-5-amd64
----------------------------------------------------------------------
I/O speed(1st run) : 78.0 MB/s
I/O speed(2nd run) : 77.0 MB/s
I/O speed(3rd run) : 76.9 MB/s
Average I/O speed : 77.3 MB/s

本来以为Debian 10 有什么特殊科技呢，IO 测试和Debian 9 差不多

下面是重头戏，回退一些Esxi 的 ACHI 的driver，再来测试一下:

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 8
CPU frequency : 3494.956 MHz
Total size of Disk : 55.0 GB (0.9 GB Used)
Total amount of Mem : 3907 MB (91 MB Used)
Total amount of Swap : 4045 MB (0 MB Used)
System uptime : 0 days, 0 hour 4 min
Load average : 0.22, 0.05, 0.02
OS : Debian GNU/Linux 9
Arch : x86_64 (64 Bit)
Kernel : 4.9.0-9-amd64
----------------------------------------------------------------------
I/O speed(1st run) : 301 MB/s
I/O speed(2nd run) : 299 MB/s
I/O speed(3rd run) : 303 MB/s
Average I/O speed : 301.0 MB/s

数据在350-370 之间乱跳

在Debian 10上，闲时IO 能到400 MB/s, 平时也基本就是300-350左右

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 8
CPU frequency : 3495.951 MHz
Total size of Disk : 55.0 GB (2.0 GB Used)
Total amount of Mem : 3897 MB (148 MB Used)
Total amount of Swap : 4045 MB (0 MB Used)
System uptime : 0 days, 0 hour 21 min
Load average : 0.00, 0.01, 0.01
OS : Debian GNU/Linux 10
Arch : x86_64 (64 Bit)
Kernel : 4.19.0-5-amd64
----------------------------------------------------------------------
I/O speed(1st run) : 306 MB/s
I/O speed(2nd run) : 300 MB/s
I/O speed(3rd run) : 299 MB/s
Average I/O speed : 301.7 MB/s

WebNX 1TB SSD IO Benchmark

Benchmark, VMWareLeave a comment

Quadranet 的 硬件实在太老了，WebNX 以硬件好，网络好而著称, 刚订购的服务器自带两个1TB SSD，而且通过smart 查询到，是全新的SSD，真是太爽了

测试使用的程序:

wget -qO- bench.sh | bash

先在promox 6.0 的Host 上测试一下IO:

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 12
CPU frequency : 3600.230 MHz
Total size of Disk : 94.0 GB (1.7 GB Used)
Total amount of Mem : 64307 MB (1237 MB Used)
Total amount of Swap : 8191 MB (0 MB Used)
System uptime : 0 days, 0 hour 34 min
Load average : 0.00, 0.00, 0.00
OS : Debian GNU/Linux 10
Arch : x86_64 (64 Bit)
Kernel : 5.0.15-1-pve
----------------------------------------------------------------------
I/O speed(1st run) : 406 MB/s
I/O speed(2nd run) : 406 MB/s
I/O speed(3rd run) : 405 MB/s
Average I/O speed : 405.7 MB/s

然后再proxmox上建立一个CentOS 7 的VM，在测试一下IO:

----------------------------------------------------------------------
CPU model : Common KVM processor
Number of cores : 4
CPU frequency : 3499.996 MHz
Total size of Disk : 29.0 GB (1.2 GB Used)
Total amount of Mem : 4358 MB (124 MB Used)
Total amount of Swap : 3275 MB (0 MB Used)
System uptime : 0 days, 0 hour 2 min
Load average : 0.20, 0.05, 0.02
OS : CentOS 7.6.1810
Arch : x86_64 (64 Bit)
Kernel : 3.10.0-957.el7.x86_64
----------------------------------------------------------------------
I/O speed(1st run) : 452 MB/s
I/O speed(2nd run) : 455 MB/s
I/O speed(3rd run) : 448 MB/s
Average I/O speed : 451.7 MB/s

下面在裸机上直接安装CentOS，来测试一下IO Benchmark:

----------------------------------------------------------------------
CPU model : Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz
Number of cores : 12
CPU frequency : 1199.920 MHz
Total size of Disk : 873.3 GB (1.3 GB Used)
Total amount of Mem : 64316 MB (503 MB Used)
Total amount of Swap : 7628 MB (0 MB Used)
System uptime : 0 days, 0 hour 7 min
Load average : 0.13, 0.07, 0.05
OS : CentOS 7.6.1810
Arch : x86_64 (64 Bit)
Kernel : 3.10.0-957.el7.x86_64
----------------------------------------------------------------------
I/O speed(1st run) : 390 MB/s
I/O speed(2nd run) : 390 MB/s
I/O speed(3rd run) : 389 MB/s
Average I/O speed : 389.7 MB/s

看来Proxmox 是有什么cache加成，造成IO 的测试最快

ESXi 和VCSA 安装部署的大概步骤

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ESXi 对硬件的要求比较高，而且也比较挑硬件，建议安装之前去vmware的官方网站仔细查看一下兼容性

硬件要求: Intel 的 CPU 最少要有两个core且 打开VT-x, 并且内存最少是8GB，Hypervisor 需要4GB，另外最少4GB安装VM

ESXi 和 VCSA 的部署严重依赖DNS 的解析，因此ESXi 和 VCSA 使用的FQDN一定要配置好DNS

1 用IPMI 安装ESXi

2 在DCUI界面，按F2配置ESXi management network，配置IPv4，关闭IPv6(需要重启), 配置DNS和hostname， hostname 如果不是FQDN，需要配置DNS suffix，然后重启

3 用ESXi所在的Host IP登录，添加NTP server

4 打开SSH权限，将sata 的driver 回退到sata-achi，然后关闭SSH权限。从安全上考虑，仅在需要SSH的时候再打开SSH，否则建议关闭

5 添加ESXi授权

 

部署VCSA， VCSA 的安装最好通过远程的 windows上(因为本地网速达不到)，对于windows来说，系统需要最少4 core 或者vCPU， 4GB RAM， 32GB storage

在vmware 的官方网站上下载好VCSA 的iso后，把他mount 在远程windows 上的虚拟光驱上，点击vcsa-ui-installer -> win32 -> installer.exe 就可以开始

安装过程简单易懂，在选择datastore 的时候可以选择 Thin Provisioning -> “Enable Thin Disk Mode”

在第二阶段的安装过程中， SSO domain 最好选择使用默认的”vsphere.local”

Online.net SSD 基于KVM虚拟化的benchmark

Benchmark, VMWareLeave a comment

机器为online.net 的 SSD 机器， VM 配置是4 vCPU 和 4 GB RAM

测试使用程序为:

wget -qO- bench.sh | bash

以下是测试结果:

----------------------------------------------------------------------
CPU model : Common KVM processor
Number of cores : 4
CPU frequency : 3495.948 MHz
Total size of Disk : 28.0 GB (1.1 GB Used)
Total amount of Mem : 4354 MB (73 MB Used)
Total amount of Swap : 4509 MB (0 MB Used)
System uptime : 0 days, 0 hour 4 min
Load average : 0.02, 0.05, 0.01
OS : Debian GNU/Linux 10
Arch : x86_64 (64 Bit)
Kernel : 4.19.0-5-amd64
----------------------------------------------------------------------
I/O speed(1st run) : 359 MB/s
I/O speed(2nd run) : 351 MB/s
I/O speed(3rd run) : 358 MB/s
Average I/O speed : 356.0 MB/s

在disk 打开cache(write back)以后的测试结果:
----------------------------------------------------------------------
CPU model            : Common KVM processor
Number of cores      : 4
CPU frequency        : 3495.948 MHz
Total size of Disk   : 28.0 GB (1.1 GB Used)
Total amount of Mem  : 4354 MB (70 MB Used)
Total amount of Swap : 4509 MB (0 MB Used)
System uptime        : 0 days, 0 hour 1 min
Load average         : 0.00, 0.00, 0.00
OS                   : Debian GNU/Linux 10
Arch                 : x86_64 (64 Bit)
Kernel               : 4.19.0-5-amd64
----------------------------------------------------------------------
I/O speed(1st run)   : 378 MB/s
I/O speed(2nd run)   : 369 MB/s
I/O speed(3rd run)   : 374 MB/s
Average I/O speed    : 373.7 MB/s