Exadata migration完成 目前采用的是物理DG switch over的方式 采用11g active duplicate 实现整个数据大小为2T左右 总共耗时约为10个小时 每秒达到近60M
采取这种方法的好处为：
1:主库无需停机
2:可以采用exadata最佳性能AU_SIZE=4M
3:复制过程中不会产生集中化IO,不过还是建议在夜里进行操作
4:可以直接switch over 使用原来的库为备库
处理完毕后 我们可以查看主机状态：
[grid@dm01db01 ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
NAME TARGET STATE SERVER STATE_DETAILS
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.DATA_DM01.dg
ONLINE ONLINE dm01db01
ONLINE ONLINE dm01db02
ora.DBFS_DG.dg
ONLINE ONLINE dm01db01
ONLINE ONLINE dm01db02
ora.LISTENER.lsnr
ONLINE ONLINE dm01db01
ONLINE ONLINE dm01db02
ora.RECO_DM01.dg
ONLINE ONLINE dm01db01
ONLINE ONLINE dm01db02
ora.asm
ONLINE ONLINE dm01db01 Started
ONLINE ONLINE dm01db02 Started
ora.gsd
OFFLINE OFFLINE dm01db01
OFFLINE OFFLINE dm01db02
ora.net1.network
ONLINE ONLINE dm01db01
ONLINE ONLINE dm01db02
ora.ons
ONLINE ONLINE dm01db01
ONLINE ONLINE dm01db02
ora.registry.acfs
ONLINE ONLINE dm01db01
ONLINE ONLINE dm01db02
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.LISTENER_SCAN1.lsnr
1 ONLINE ONLINE dm01db02
ora.cvu
1 ONLINE ONLINE dm01db02
ora.dm01db01.vip
1 ONLINE ONLINE dm01db01
ora.dm01db02.vip
1 ONLINE ONLINE dm01db02
ora.edw1.db
1 ONLINE ONLINE dm01db01 Open
2 ONLINE ONLINE dm01db02 Open
ora.oc4j
1 ONLINE ONLINE dm01db02
ora.scan1.vip
1 ONLINE ONLINE dm01db02
[grid@dm01db01 ~]$
SQL> /
GROUP_NUMBER NAME VALUE
------------ ------------------------------------------------------------ ------------------------------------------------------------
1 access_control.enabled FALSE
1 access_control.umask 066
1 au_size 4194304
1 cell.smart_scan_capable TRUE
1 compatible.asm 11.2.0.2.0
1 compatible.rdbms 11.2.0.2.0
1 disk_repair_time 3.6h
1 idp.boundary auto
1 idp.type dynamic
1 sector_size 512
1 template.ARCHIVELOG.mirror_region 0可以看到 au_size=4194304 使用了oracle推荐的best au_size for exadata 对于4M这个数值 可以参考这篇文章 exadata AU_SIZE
通过上图可以看到au size 4m对于exadata的 smart scan io 提升比较明显,另外测试发现11g active duplicate 对于 “cell physical IO bytes saved during optimized RMAN file restore”并没有影响
SQL> SELECT name, value/1024/1024 MB from v$sysstat a WHERE 2 a.name = 'physical read total bytes' OR a.name = 'physical write total bytes' OR a.name = 'cell physical IO interconnect bytes' OR a.name = 'cell physical IO bytes eligible for predicate offload' OR a.name = 'cell physical IO bytes saved during optimized file creation' OR a.name = 'cell physical IO bytes saved during optimized RMAN file restore' OR a.name = 'cell IO uncompressed bytes' OR a.name = 'cell physical IO interconnect bytes returned by smart scan' OR a.name = 'cell physical IO bytes saved by storage index'; 3 4 5 6 7 8 9 10 NAME MB ---------------------------------------------------------------- ---------- physical read total bytes 2043013.32 physical write total bytes 187975.958 cell physical IO interconnect bytes 1497804.22 cell physical IO bytes saved during optimized file creation 0 cell physical IO bytes saved during optimized RMAN file restore 0 cell physical IO bytes eligible for predicate offload 1042550.99 cell physical IO bytes saved by storage index 127372.633 cell physical IO interconnect bytes returned by smart scan 119367.207 cell IO uncompressed bytes 915887.641
关于v$sysstat对于ed cell的statistics 可以参照下表
| Statistic | Description |
|---|---|
|
|
The number of read requests that were a cache hit on exadata flash cache. |
|
|
The total size of uncompressed data that is processed on the cell. For scan on hybrid-columnar-compressed tables, this statistic is the size of data after decompression. |
|
|
The number of bytes that are returned by the cell for Smart Scan only, and does not include bytes for other database I/O. |
|
|
The number of bytes saved by storage index. |
|
|
The total number of I/O bytes processed with physical disks when processing was offloaded to the cell. |
|
|
The number of I/O bytes sent back to the database server for processing due to CPU usage on Exadata Cell. |
|
|
The number of I/O bytes saved by the database host by offloading the file creation operation to cells. This statistic shows the Exadata Cell benefit due to optimized file creation operations. |
|
|
The number of I/O bytes saved by the database host by offloading the RMAN file restore operation to cells. This statistic shows the Exadata Cell benefit due to optimized RMAN file restore operations. |
|
|
The number of I/O bytes exchanged over the interconnection between the database host and cells. |
|
|
Total number of read requests satisfied either by using Exadata Smart Flash Cache or storage index. |
|
|
Total amount of I/O bytes for reads processed with physical disks. This includes when processing was offloaded to the cell and when processing was not offloaded. |
|
|
Total number of bytes read from Exadata Smart Flash Cache or storage index. |
|
|
Total amount of I/O bytes for writes processed with physical disks. This includes when processing was offloaded to the cell and when processing was not offloaded. |
另外官方也给出了几种解决exadata migration的方案
Tip:
ASM Online Migration: This method is only applicable if your database is already using ASM and you do not need to adjust the ASM allocation unit (AU) size. To use this method you must also be able to connect your current database storage to Database Machine and migrate the database instances to Database Machine. After migrating the database instances, the data migration is very simple, just add new Exadata-based grid disks to your ASM disk groups and drop existing disks from your ASM disk groups to migrate the data.
当然迁移的方法还有很多OGG,DSG,甚至DDS。但是需要说明的一点是当使用ASM Online Migration时 虽然不严格要求AU_SIZE(best practice for 4M in ED) 相同 但是不同AU_SIZE的migration 会影响迁移之后的性能
