ASM 规划问题

mangmangdream

底层raid0+1
创建ASM DG的时候，每个ASM DISK的大小和ASM DG中disk的数据量对性能有什么影响？

Maclean Liu(刘相兵

ODM Finding:

1. Lun Size And Performance Impact With Asm [ID 373242.1]
   
2. 
   
3. Applies to:
   
4. Oracle Server - Enterprise Edition - Version: 10.2.0.2 and later   [Release: 10.2 and later ]
   
5. Information in this document applies to any platform.
   
6. ***Checked for relevance on 27-Feb-2011***
   
7. Goal
   
8. 
   
9. QUESTION
   
10. 
    
11. What is the maximum LUN size we can use without performance degradation? For example, is 1 TB or 2TB sized LUNs perform the same as 100 GB or 200 GB sized LUNs?
    
12. 
    
13. We are using the ASM feature of Oracle DB 10g release 2 on 64-bit Solaris 9 or Solaris 10.
    
14. 
    
15. Solution
    
16. 
    
17. ANSWER
    
18. 
    
19. Size alone should not affect the performance of a LUN. The underlying hardware is what counts. There is no magic number for the LUN size. Seek the advice of the storage vendor to recommend the best configuration from a raid 1 or 5 perspective for performance and availability since this may vary between vendors. Given a database size and storage hardware you have available, our best practice recommends creating larger LUNs (if possible to reduce LUN management for the sys admins) and create LUNs from separate set of storage arrays (drives) so that LUNs are not sharing drives if possible.
    
20. 
    
21. For larger LUNs it is recommended using a large ALLOCATION UNIT.

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Maclean Liu(刘相兵

- Maximize the number of disks in a disk group for maximum data distribution and higher I/O bandwidth
=> 最大化ASM DISK磁盘数量 有助于提高IO带宽和数据分布， 当然这并不绝对， 不要因此而划分大量 小尺寸的LUN DISK

- Size alone should not affect the performance of a LUN. The underlying hardware is what counts.
=> 单个ASM disk的大小并不会对性能有太大的影响

There is no magic number for the LUN size
=》 对于LUN Disk的大小没有一个 万能值， 一般单个ASM LUN DISK的大小控制在50-300GB范围内

- For larger LUNs it is recommended using a large ALLOCATION UNIT.
=》　建议对大的LUN  使用大的 AU ALLOCATION UNIT.

视乎具体的Storage Vendor ，存储供应商 他们也会在POC的测试中积累一些经验，例如EMC 厂商认为 最小化 ASM Disk Number数量有助于性能

The provieder of the Storage EMC-Vmax say that the LUNS size can be 200 GB for database OLTP.

We believe that the premise or EMC_Vmax contradicts to ORACLE so instead of maximize the disks they pretend minimize the disks of the DISK GROUP.


参考http://www.oracledatabase12g.com ... te-id-452924-1.html