oracle一体机中，把部分flash空间划分到griddisk中，当做闪存存储来使用-How to reassign part of your cell flashdisk/flashcache for use in a Flash Disk diskgroup

1) Drop the current FlashCache (on every CELL):

第一步删除所有节点的cache

CellCLI> drop flashcache
Flash cache exa1cel01_FLASHCACHE successfully dropped

　　

2) Recreate and resize down the FlashCache to a smaller size as follows (on every CELL):

设置每个cell节点可用闪存的大小

CellCLI> create flashcache all size=288g
Flash cache exa1cel01_FLASHCACHE successfully created

　　

3) Then create Flash GridDisks using the remaining space in the Flash disks cards as follows (on every CELL):

创建每个节点闪存空间的大小，并命名

CellCLI> CREATE GRIDDISK ALL FLASHDISK PREFIX='FDOM'
GridDisk FDOM_FD_00_cell01 successfully created
GridDisk FDOM_FD_01_cell01 successfully created
GridDisk FDOM_FD_02_cell01 successfully created
GridDisk FDOM_FD_03_cell01 successfully created
GridDisk FDOM_FD_04_cell01 successfully created
GridDisk FDOM_FD_05_cell01 successfully created
GridDisk FDOM_FD_06_cell01 successfully created
GridDisk FDOM_FD_07_cell01 successfully created
GridDisk FDOM_FD_08_cell01 successfully created
GridDisk FDOM_FD_09_cell01 successfully created
GridDisk FDOM_FD_10_cell01 successfully created
GridDisk FDOM_FD_11_cell01 successfully created
GridDisk FDOM_FD_12_cell01 successfully created
GridDisk FDOM_FD_13_cell01 successfully created
GridDisk FDOM_FD_14_cell01 successfully created
GridDisk FDOM_FD_15_cell01 successfully created

CellCLI> LIST GRIDDISK
FDOM_FD_00_cell01 active
FDOM_FD_01_cell01 active
FDOM_FD_02_cell01 active
FDOM_FD_03_cell01 active
FDOM_FD_04_cell01 active
FDOM_FD_05_cell01 active
FDOM_FD_06_cell01 active
FDOM_FD_07_cell01 active
FDOM_FD_08_cell01 active
FDOM_FD_09_cell01 active
FDOM_FD_10_cell01 active
FDOM_FD_11_cell01 active
FDOM_FD_12_cell01 active
FDOM_FD_13_cell01 active
FDOM_FD_14_cell01 active
FDOM_FD_15_cell01 active

　Then connect to an ASM instance and run:

SQL> CREATE diskgroup FLASH1 normal redundancy disk 'o/*/FDOM*' attribute 'compatible.rdbms'='11.2.0.0.0', 'compatible.asm'='11.2.0.0.0', 'cell.smart_scan_capable'='TRUE', 'au_size'='4M;

　To view diskgroups including this new one:

SQL> SELECT name, size from v$asm_diskgroup;

　

Of course if you are already on 12.1.x.x.x- you can set the two COMPATIBLE settings to the version you are on.

Also- if this works for you- we can always drop the diskgroup and extend this same process to all your cell servers.
The recreate the diskgroup using all the FLASH griddisks

You can also make the flashcache even smaller. and your FDOM GRIDDISKS even bigger.

Don't forget that some of the speed of cell servers is the flashcache.

So reducing the size of this on the cells will cause an overall degredation in your overall cell performance.