02云计算虚拟化技术 存储虚拟化技术

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2 3
1 4
智能存储系统: 缓存Fra Baidu bibliotek
Host
Connectivity
智能磁盘系统
Front End
Cache
Back End
Physical Disks
Disk Storage Systems
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智能存储系统: 后端
Host
Connectivity
智能磁盘系统
Front End
Cache
Physical Disks
Ports
Controllers
Note: Include redundancy in the channels to and from the ports.
Disk Storage Systems
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前端请求队列排序技术-- 智能技术之一
Without Command Queuing
Moderate but more than RAID 5
Very good for random reads
Good for sequential reads
Good for small, random writes
(has write penalty)
4
50
High
Very good
Good
数据存储的分类
存储的类型…..
存储的概念
• 存储的概念非常广泛 (Storage)，广义的存储是指基 本的数据保存的概念。
• 用于计算机设备的专用存储设备（Storage Array/Disk Array）
• Array 的含义
– 1.(军队等的)列阵[U] – 2.(排列整齐的)一批;一系列;大量
• 存储阵列 / 磁盘阵列 – 网络存储阵列
• 1987年 -- RAID 技术出现
– 加州柏克大学的三位人员发表了名为“磁盘阵列控制器研究”的 论文，正式提到了RAID也就是磁盘阵列控制器，论文提出廉价的 5.25"及3.5"的硬盘也能如大机器上的8"盘般提供大容量、高性能 和数据的一致性，并详述了RAID 1至5的技术。
磁盘阵列的发展过程
dedicated parity disk • 5 Striped array with independent disks and distributed
parity • 6 Striped array with independent disks and dual
distributed parity
云计算虚拟化技术
存储虚拟化技术
2012年03月13
爆炸性增长的数据
• 全球数据量的发展
• 2011年全球数据量 1.8 ZB • 1 ZB= 1024 EB= 1024*1024 PB =
1024*1024*0124TB=1024*1024*1024*1024GB
计算机里面的存储设备或部件有哪些？
Raid 5
Block 40
Host
GCBeoPRnloaeAtcrrrIiokaDtyltl04eedr P 04 15 26 37
Block 0 Block 4
Block 1 Block 5
Block 2 Block 6
Block 3 P4567
P0123 Block 7
计算IOPS
• Total IOPS at peak workload is 1200 • Read/Write ratio 2:1 • Calculate IOPS requirement at peak activity
Strip
Stripe 1 Stripe 2
Strip 1
Stripe Strip 2
Strip 3
Strips
Raid 分级
• 0 Striped array with no fault tolerance • 1 Disk mirroring • Nested RAID (i.e., 1 + 0, 0 + 1, etc.) • 3 Parallel access array with dedicated parity disk • 4 Striped array with independent disks and a
Port Port
Port Port
LUN LUN LUN
Very good
1
3
5
6 1+0 and 0+1
2
50
High
Good Better than a single disk
Good Slower than a single disk,
as every write must be committed to two disks
3
(n-1)*100/n where n= number of disks
智能存储系统的构成组件
Host
Connectivity
智能磁盘系统
Front End
Cache
Back End
Cache
Physical Disks
Disk Storage Systems
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智能存储系统: 前端
Host
Connectivity
智能磁盘系统
Front End
Cache
Back End
Moderate
Very good for random reads
Good for sequential reads
Fair for random write Slower due to parity
overhead Fair to good for sequential writes
4
(n-2)*100/n where n= number of disks
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Network Connected
Entities
什么是DAS
Internal Direct Connect
External Direct Connect
DAS的几种类型
• IDE 优点：价格低廉、兼容性好 • SCSI 优点：适应面广、高性能、同时具备内外置 • FC 优点：带宽高、连接距离长、连接设备数量大 • SATA 优点：一对一连接、独享带宽、支持热插拔、低电压 • SAS 优点：兼容性好、数据传输率高
磁盘阵列（Disk Array）是由一个或多个硬盘控制器 来控制多个硬盘的相互连接，使多个硬盘的读写同 步，减少错误，增加效率和可靠度的技术。
存储重要历史回顾
• 1956年9月
– IBM的一个工程小组向世界展示了第一台磁盘存储系统IBM 350 RAMAC（Random Access Method of Accounting and Control），其 磁头可以直接移动到盘片上的任何一块存储区域，从而成功地实 现了随机存储，这套系统的总容量只有5MB，共使用了50个直径 为24英寸的磁盘，这些盘片表面涂有一层磁性物质，它们被叠起 来固定在一起，绕着同一个轴旋转。此款RAMAC在那时主要用于 飞机预约、自动银行、医学诊断及太空领域内。
Request 1 Request 2
Request 3 Request 4
F R O N 4321 T
E N D
2 1
3 4
With Command Queuing
Request 1 Request 2
Request 3 Request 4
F R O N 423 1 T
E N D
Disk Storage Systems
Host A
Host B Host C
现在的阵列产品: 智能磁盘阵列产 品
Highly optimized for I/O processing.
Host A Host B Host C
Cache for improving I/O performance.
Operating environments provide:
SCSI的地址分类
Target (Front-end port) Target – t0
Port
Host
Initiator (HBA) Controller – c0
Host Addressing: Storage Volume 1 - c0t0d0 Storage Volume 2 - c0t0d1 Storage Volume 3 - c0t0d2
我们对存储的要求 – 可靠
“A Case for Redundant Arrays of Inexpensive Disks (RAID).”
RAID Controller
Physical Array
Logical Array
Hard Disks
Host
RAID Array
如何进行磁盘空间管理 Stripe
• Introduced by IBM in 1956.
Disk Mainframe
JBOD 阵列 - “傻盘”
Host
• Multiple physical disks in an external cabinet.
• Array connects to a single server only.
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我们对存储的要求
• 快速寻找
Storage System
我们对存储的要求
• 高速获得
External transfer rate measured here
Internal transfer rate measured here
HBA
Interface
Buffer
Disk Drive
Head Disk Assembly
Moderate
Good for random reads and very good for sequential reads
Poor to fair for small random writes Good for large,
sequential writes
3
(n-1)*100/n where n= number of disks
Back End
Physical Disks
Disk Storage Systems
Controllers
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Ports
智能存储系统: 硬盘
Host
Connectivity
智能磁盘系统
Front End
Cache
Back End
Physical Disks
Disk Storage Systems
• DASD
– direct access storage device 直接存取存储设备
• JBOD
– Just Bundle Of Disks "简单磁盘捆绑"或者“磁盘簇”
• Disk Array
– 磁盘阵列
• “Intelligent” Disk Arrays
– 智能磁盘阵列
Types of Disk Systems: DASD
Multiple host I/O channels.
Can be partitioned to allow each host to access its own set of drives.
Host A Host B Host C
Disk Array Controller
Disk 1 Disk 2 Disk 3 Disk 4 Disk 5
for
– RAID 1/0 – RAID 5
Raid 级别划分
RAID
Min Disks
Storage Efficiency %
0
2
100
Cost
Low
Read Performance
Very good for both random and sequential
read
Write Performance
• Data not protected by JBOD
Disk Disk Disk Disk Disk
Array
基本磁盘阵列
Array controllers for optimized I/O operations and RAID calculations.
Higher speed interconnects between drives than JBODs.
▪ Intelligence for managing Cache, ▪ Array resource allocation,
Disk Array Controller
▪ Host access to Array resources, ▪ Connectivity for heterogeneous Hosts Disk 1 Disk 2 Disk 3 Disk 4 Disk 5
LAN FC SAN
Multi Protocol Router
Internal DAS
JBOD
RAID Array
SAN / NAS
IP SAN
数据如何存储
连接协议
Tightly Connected Entities
Directly Attached Entities
Storage System