rhca 442 hardware profiling

##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 內部寄存器:硬件,時鐘週期一致.1級緩存:靜態內存,2級緩存:動態高速內存 Memory 相對緩存更慢 Storage 更慢 到磁盤，終止。 Farthe from CPU,slower,bigger,less frequently accessed Three elements of X86 machine, the ways to use system 針對X86結構 I/O address IRQ DMA

###CPU profile 指標

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 操做系統認爲你有兩個cpu,Hz是跑步的頻率，步子多大無關係
Caches size, L1, L2, L3, private or shared 
>lscpu

>L1d cache:32k L1緩存分爲數據緩存

>L1i cache:32k &指令緩存

>L2 cache:3072K

>cpu(s):4 cpu數量爲1

>Thread(s) per core:1 每顆物理CPU，1爲無超線程

>Core(s) per socket:2 每顆物理CPU有兩個核心

>Socket(s):2 兩顆物理CPU

CPU features-VT,Architecture 虛擬化,架構64/32 
>是否支持64 cat /proc/cpuinfo |egrep '(lm)|(pae)'

Motherboard chipset 主板芯片組，決定主板和CPU效率

No.of sockets,cores,hyper thereading support

Interconnect between sockets 物理CPU多顆時。前端總線聯繫FSB/qpi/amd 物理CPU之間通信手段

###TOP CPUs

intel E7-8830
8 cores,16 threads 8核，16線程
24M cache, 2.13 GHz,QPI

AMD 6284 SE
16 cores
16M cache 2.7GHz

##Memory profile 內存

Memory size, max allowed
> free -m

>cat /proc/meminfo

Memory technology,bandwidth and latency 內存第幾代技術，以及帶寬延時

>DDR2(2 bits),DDR3(4bits),DDR4(8 bits),Rambus(pS/2)

>Latency(wait time before read agin,in ns) 反映速度 納秒級 列刷新頻率

>ECC 內存故障修復 發現內存位失效 糾正 減速 slower safer

Method of memory accessing- UMA NUMA

	頻率/2=速率 2133/2~~ 1G

UMA or SMP

>MCH 內存控制器 速度瓶頸  pcieX16 顯卡佔用 卡死了 這是北橋

>ICH 南橋連外設 sata usb pcie*1

NUMA 架構

>兩個CPU本身管理本身內存，MCH內置到CPU

>IOH 僞北橋，IO控制器

>ICH 南橋同樣

NUMA form apple Mac Pro

>MCH & ICH ->I/O HUB 內設& I/O CONTROLLER 外設..GPU很近

##Storage Profile

Type of storage used
> Mechanical magnetic platters 盤片 ，磁碟

> SSD devices

###Hardware RAID level, no. of disks, striping size

Interconnect type for direct attached storage 內部存儲
>SATA SAS IDE	 IDE沒人用了 sata企業級,第三代sata完虐sas sas可靠

SCSI,FIBRE,CHANNEL,ISCSI PCI總線接駁，光纖，互聯網

> 帶寬，納秒級，便宜

burstspped vs. average speed 順序讀寫 隨機讀寫

###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 一個單元存多位閃的多壽命短
SLC 很貴，很是貴

每次讀至少一個block

####SSD TRIM COMMAND

when os erases a file, the file will typically be marked for deletion
SSD 不停作垃圾回收
ssd 掛載 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