##hardware profiling
##RH442 Getting to know your hardware
###Hardware profiling Before tuning the performance, it's important to understand the capabilities of your system CPU 内部寄存器:硬件,时钟周期一致.1级缓存:静态内存,2级缓存:动态高速内存 Memory 相对缓存更慢 Storage 更慢 到磁盘，终止。 Farthe from CPU,slower,bigger,less frequently accessed Three elements of X86 machine, the ways to use system 针对X86结构 I/O address IRQ DMA
###CPU profile 指标
grep CPU /proc/cpuinfo
model name : Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz
model name : Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz
Model,Hz 操作系统认为你有两个cpu,Hz是跑步的频率，步子多大无关系
Caches size, L1, L2, L3, private or shared
>lscpu
>L1d cache:32k L1缓存分为数据缓存
>L1i cache:32k &指令缓存
>L2 cache:3072K
>cpu(s):4 cpu数量为1
>Thread(s) per core:1 每颗物理CPU，1为无超线程
>Core(s) per socket:2 每颗物理CPU有两个核心
>Socket(s):2 两颗物理CPU
CPU features-VT,Architecture 虚拟化,架构64/32
>是否支持64 cat /proc/cpuinfo |egrep '(lm)|(pae)'
Motherboard chipset 主板芯片组，决定主板和CPU效率
No.of sockets,cores,hyper thereading support
Interconnect between sockets 物理CPU多颗时。前端总线联系FSB/qpi/amd 物理CPU之间通讯手段
###TOP CPUs
intel E7-8830
8 cores,16 threads 8核，16线程
24M cache, 2.13 GHz,QPI
AMD 6284 SE
16 cores
16M cache 2.7GHz
##Memory profile 内存
Memory size, max allowed
> free -m
>cat /proc/meminfo
Memory technology,bandwidth and latency 内存第几代技术，以及带宽延时
>DDR2(2 bits),DDR3(4bits),DDR4(8 bits),Rambus(pS/2)
>Latency(wait time before read agin,in ns) 反映速度 纳秒级 列刷新频率
>ECC 内存故障修复 发现内存位失效 纠正 减速 slower safer
Method of memory accessing- UMA NUMA
频率/2=速率 2133/2~~ 1G
UMA or SMP
>MCH 内存控制器 速度瓶颈 pcieX16 显卡占用 卡死了 这是北桥
>ICH 南桥连外设 sata usb pcie*1
NUMA 架构
>两个CPU自己管理自己内存，MCH内置到CPU
>IOH 伪北桥，IO控制器
>ICH 南桥一样
NUMA form apple Mac Pro
>MCH & ICH ->I/O HUB 内设& I/O CONTROLLER 外设..GPU很近
##Storage Profile
Type of storage used
> Mechanical magnetic platters 盘片 ，磁碟
> SSD devices
###Hardware RAID level, no. of disks, striping size
Interconnect type for direct attached storage 内部存储
>SATA SAS IDE IDE没人用了 sata企业级,第三代sata完虐sas sas可靠
SCSI,FIBRE,CHANNEL,ISCSI PCI总线接驳，光纤，互联网
> 带宽，纳秒级，便宜
burstspped vs. average speed 顺序读写 随机读写
###SSD
Electronic disk , no moving mechanical components
No start-up time
Very low latency on read and write
Faster than traditional HD sequence 500M/S 200M/S
Silent ,not so hot ,vibration free, magnet free,light,less power required
Much more expensive,lesser capacity
Potentially longer life time
MLC 一个单元存多位闪的多寿命短
SLC 很贵，非常贵
每次读至少一个block
####SSD TRIM COMMAND
when os erases a file, the file will typically be marked for deletion
SSD 不停做垃圾回收
ssd 挂载 fstab default,discard
>IDE UP 133MB/S
>SATA2 300
>SATA3 600
>SCSI 320
>USB2 60
>USB3 600
>ISCSI GIGA NIC 125
>FIBRE CHANNEL 531
###PCI EXPRESS
>1.0a 2Gb/s bandwidth:2.5GT/s singleLane:250Mb/s full16:8GB/s
>2.1 4 5 500 16
>3 8 8 1GB/s 32
##Networking profile
Network card model
Network technology
Connection to switch(Speed)
Separated network, special purpose network -Storage,VDI,administration,useradta
I/O virtualization
>cmd
>dmesg
>/var/log/dmesg
>lscpu,lscpu -p
>getconf -a
>x86info
##profiling commands
>cmd
>dmidecode
>/sys/class/dmi
>lspci [-v[-v[-v]]]
>lsusb [-v]
>ethtool
>sosreport
>powertop