Flex ASM

Flex ASM

flex ASM에서는 클러스터로 이루어진 서버들의 숫자보다 더 적은 수의 ASM 인스턴스로 운영이 가능하며,
적용되는 ASM의 최대 인스턴스의 개수를 ASM 카디널리티라고 한다.

만약 ASM 인스턴스가 실패할 경우 클러스터웨어는 다른 서버에 ASM 인스턴스를 기동시켜 ASM 카디널리티를 유지하게 된다.
이 때 데이터베이스는 ASM 인스턴스가 실패시 같이 데이터베이스가 실패되는 것이 아닌, 다른 ASM 인스턴스로 연결이 된다.
ASM 카디널리티의 기본값은 3이며, 클러스터웨어 명령을 통해 원하는 숫자로 변경이 가능하다.

Flex ASM 특징
 - ASM diskgroup의 최대 개수가 63개에서 511개로 증가
 - 더 큰 LUN 사이즈 지원(32PB)
 - Disk Group 내의 ASM Disk 이름 변경 가능



[grid@server1 ~]$ asmcmd showclusterstate
Normal

현재 기동중인 ASM이 Flex ASM인지 확인하는 명령어,
[grid@server1 ~]$ asmcmd showclustermode
ASM cluster : Flex mode enabled

ASM 인스턴스 카디널리티

[grid@rac1 ~]$ srvctl config asm
ASM home: <CRS home>
Password file: +SYSVOL/orapwASM
ASM listener: LISTENER
ASM instance count: 3               ==============> 카디널리티
Cluster ASM listener: ASMNETLSNR_ASM

현재 ASM Instance 가 어느 노드에서 떠 있는지를 확인하기 위해서는 SRVCTL 명령으로 확인 할 수 있다

[grid@rac1 ~]$ srvctl status asm -detail
ASM is running on rac1,rac2,rac3
ASM is enabled.

카디널리티 변경
$ srvctl modify asm –count n

n 값이 변경할 카디널리티



[grid@server3 ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
Name           Target  State        Server                State details
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.ASMNET1LSNR_ASM.lsnr
               ONLINE  ONLINE       server1               STABLE
               ONLINE  ONLINE       server2               STABLE
               ONLINE  ONLINE       server3               STABLE

[root@server1 usr]# srvctl config asm
ASM home: /u01/app/12.1.0.1/grid
Password file: +OCR/orapwASM
ASM listener: LISTENER
ASM instance count: 3
Cluster ASM listener: ASMNET1LSNR_ASM


[grid@server1 ~]$ srvctl modify asm -count 2
[grid@server1 ~]$ srvctl status asm
ASM is running on server3,server1


SQL> select dg.name,c.instance_name,c.db_name,c.status
  2  from v$asm_diskgroup dg, v$asm_client c
  3  where dg.group_number = c.group_number
  4 and c.db_name = 'ORCL'
  5 /
 
NAME       INSTANCE_N DB_NAME  STATUS
---------- ---------- -------- ------------
DATA       ORCL2      ORCL     CONNECTED
DATA       ORCL1      ORCL     CONNECTED


사일런트 모드로 ASM을 flex ASM으로 변경
asmca -silent 
     -convertToFlexASM 
     -asmNetworks interface_name/subnet
     -asmListenerPort ASM_listener_port_number


/app/aime/cfgtoollogs/asmca/scripts/converttoFlexASM.sh


flex asm 설치시 response file 정보

oracle.install.crs.config.storageOption=FLEX_ASM_STORAGE