文檔來源：
Third ASM resource(ora.asm) listed in "crsctl stat res -t" for two node RAC in 12c (文檔 ID 2132715.1)
[grid@rac2 ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
Name Target State Server State details
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.LISTENER.lsnr
ONLINE ONLINE rac1 STABLE
ONLINE ONLINE rac2 STABLE
ora.chad
ONLINE ONLINE rac1 STABLE
ONLINE ONLINE rac2 STABLE
ora.net1.network
ONLINE ONLINE rac1 STABLE
ONLINE ONLINE rac2 STABLE
ora.ons
ONLINE ONLINE rac1 STABLE
ONLINE ONLINE rac2 STABLE
ora.proxy_advm
OFFLINE OFFLINE rac1 STABLE
OFFLINE OFFLINE rac2 STABLE
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.ASMNET1LSNR_ASM.lsnr(ora.asmgroup)
1 ONLINE ONLINE rac1 STABLE
2 ONLINE ONLINE rac2 STABLE
3 ONLINE OFFLINE STABLE
ora.DATA.dg(ora.asmgroup)
1 ONLINE ONLINE rac1 STABLE
2 ONLINE ONLINE rac2 STABLE
3 OFFLINE OFFLINE STABLE
ora.FRA.dg(ora.asmgroup)
1 ONLINE ONLINE rac1 STABLE
2 ONLINE ONLINE rac2 STABLE
3 OFFLINE OFFLINE STABLE
ora.LISTENER_SCAN1.lsnr
1 ONLINE ONLINE rac1 STABLE
ora.OCR.dg(ora.asmgroup)
1 ONLINE ONLINE rac1 STABLE
2 ONLINE ONLINE rac2 STABLE
3 OFFLINE OFFLINE STABLE
ora.asm(ora.asmgroup)
1 ONLINE ONLINE rac1 Started,STABLE
2 ONLINE ONLINE rac2 Started,STABLE
3 OFFLINE OFFLINE STABLE
ora.asmnet1.asmnetwork(ora.asmgroup)
1 ONLINE ONLINE rac1 STABLE
2 ONLINE ONLINE rac2 STABLE
3 OFFLINE OFFLINE STABLE
ora.cvu
1 ONLINE ONLINE rac1 STABLE
ora.dongsc.db
1 ONLINE ONLINE rac1 Open,HOME=/u01/app/o
racle/product/19.3.0
/dbhome_1,STABLE
2 ONLINE ONLINE rac2 Open,HOME=/u01/app/o
racle/product/19.3.0
/dbhome_1,STABLE
ora.qosmserver
1 ONLINE ONLINE rac1 STABLE
ora.rac1.vip
1 ONLINE ONLINE rac1 STABLE
ora.rac2.vip
1 ONLINE ONLINE rac2 STABLE
ora.scan1.vip
1 ONLINE ONLINE rac1 STABLE
--------------------------------------------------------------------------------
RAC只有2個節點，但是crsctl卻顯示3個節點asm的信息：
[grid@rac1 ~]$ olsnodes -n
rac1 1
rac2 2
SOLUTION：
當使用FLEX ASM時，默認就是3個ASM實例，即使RAC環境中只有2個節點，所以我們看到的輸出是正常的。
爲了確認這個，我們看一下ASM的詳細信息：
[grid@rac1 ~]$ srvctl config asm
ASM 主目錄: <CRS home>
口令文件: +OCR/orapwASM
口令文件備份: +OCR/orapwASM_backup
ASM 監聽程序: LISTENER
ASM 實例計數: 3
集羣 ASM 監聽程序: ASMNET1LSNR_ASM
但是，我們仍然可以將基數改爲2，但是假如這樣，當我們擴展集羣添加節點時，它也依然是2不是3，所以建議保持默認。
假如有特殊要求，必須顯示2個（例如某些監控軟件）
srvctl modify asm -h
Modifies the configuration for ASM.
Usage: srvctl modify asm [-listener <lsnr_name>] [-pwfile <password_file_path>] [-count {<number_of_instances>|ALL}] [-force]
-listener <lsnr_name> Listener name
-pwfile <password_file_path> Password file path
-count <number_of_instances>|ALL The number of instances or ALL to have instances on all nodes
-force Force modification (ignore dependencies)
-help Print usage