有客户咨询，认为19c RAC集群资源状态和11g RAC大不一样，比如在他们的19c集群，也是只部署2节点，却显示3个资源状态，其中第三个还是offline状态，担心是否有影响。
实际上这和Flex ASM特性有关，是正常的现象，其实不去修改也并不会影响什么。
找一个19c RAC（2 nodes）环境来演示，当前查询集群资源状态：
[grid@db193 ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
Name Target State Server State details
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.LISTENER.lsnr
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.chad
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.net1.network
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.ons
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.ASMNET1LSNR_ASM.lsnr(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 OFFLINE OFFLINE STABLE
ora.CRS.dg(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 ONLINE OFFLINE STABLE
ora.DATA.dg(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 ONLINE OFFLINE STABLE
ora.LISTENER_SCAN1.lsnr
1 ONLINE ONLINE db193 STABLE
ora.asm(ora.asmgroup)
1 ONLINE ONLINE db193 Started,STABLE
2 ONLINE ONLINE db195 Started,STABLE
3 OFFLINE OFFLINE STABLE
ora.asmnet1.asmnetwork(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 ONLINE OFFLINE STABLE
ora.cvu
1 ONLINE ONLINE db193 STABLE
ora.db193.vip
1 ONLINE ONLINE db193 STABLE
ora.db195.vip
1 ONLINE ONLINE db195 STABLE
ora.jydb.cmdb1.svc
2 ONLINE ONLINE db193 STABLE
ora.jydb.db
1 ONLINE ONLINE db193 Open,HOME=/u01/app/o
racle/product/19.3.0
/db_1,STABLE
2 ONLINE ONLINE db195 Open,HOME=/u01/app/o
racle/product/19.3.0
/db_1,STABLE
ora.qosmserver
1 ONLINE ONLINE db193 STABLE
ora.scan1.vip
1 ONLINE ONLINE db193 STABLE
--------------------------------------------------------------------------------
[grid@db193 ~]$
可以查看配置验证，确认就是Flex ASM，当前ASM配置实例数量为3：
[grid@db193 ~]$ asmcmd showclustermode
ASM cluster : Flex mode enabled - Direct Storage Access
[grid@db193 ~]$ srvctl config asm
ASM home: <CRS home>
Password file: +CRS/orapwASM
Backup of Password file: +CRS/orapwASM_backup
ASM listener: LISTENER
ASM instance count: 3
Cluster ASM listener: ASMNET1LSNR_ASM
[grid@db193 ~]$
而这个ASM实例数量其实也可以按需修改，比如：
修改ASM实例数量为4，查看集群资源状态：
$ srvctl modify asm -count 4
[grid@db193 ~]$ srvctl modify asm -count 4
[grid@db193 ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
Name Target State Server State details
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.LISTENER.lsnr
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.chad
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.net1.network
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.ons
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.ASMNET1LSNR_ASM.lsnr(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 OFFLINE OFFLINE STABLE
4 OFFLINE OFFLINE STABLE
ora.CRS.dg(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 ONLINE OFFLINE STABLE
4 ONLINE OFFLINE STABLE
ora.DATA.dg(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 ONLINE OFFLINE STABLE
4 ONLINE OFFLINE STABLE
ora.LISTENER_SCAN1.lsnr
1 ONLINE ONLINE db193 STABLE
ora.asm(ora.asmgroup)
1 ONLINE ONLINE db193 Started,STABLE
2 ONLINE ONLINE db195 Started,STABLE
3 OFFLINE OFFLINE STABLE
4 OFFLINE OFFLINE STABLE
ora.asmnet1.asmnetwork(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
3 ONLINE OFFLINE STABLE
4 ONLINE OFFLINE STABLE
ora.cvu
1 ONLINE ONLINE db193 STABLE
ora.db193.vip
1 ONLINE ONLINE db193 STABLE
ora.db195.vip
1 ONLINE ONLINE db195 STABLE
ora.jydb.cmdb1.svc
2 ONLINE ONLINE db193 STABLE
ora.jydb.db
1 ONLINE ONLINE db193 Open,HOME=/u01/app/o
racle/product/19.3.0
/db_1,STABLE
2 ONLINE ONLINE db195 Open,HOME=/u01/app/o
racle/product/19.3.0
/db_1,STABLE
ora.qosmserver
1 ONLINE ONLINE db193 STABLE
ora.scan1.vip
1 ONLINE ONLINE db193 STABLE
--------------------------------------------------------------------------------
如果看起来很不习惯，也可以修改
srvctl modify asm -count 2
或者
srvctl modify asm -count ALL
[grid@db193 ~]$ srvctl modify asm -count ALL
[grid@db193 ~]$ crsctl stat res -t
--------------------------------------------------------------------------------
Name Target State Server State details
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.LISTENER.lsnr
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.chad
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.net1.network
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
ora.ons
ONLINE ONLINE db193 STABLE
ONLINE ONLINE db195 STABLE
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.ASMNET1LSNR_ASM.lsnr(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
ora.CRS.dg(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
ora.DATA.dg(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
ora.LISTENER_SCAN1.lsnr
1 ONLINE ONLINE db193 STABLE
ora.asm(ora.asmgroup)
1 ONLINE ONLINE db193 Started,STABLE
2 ONLINE ONLINE db195 Started,STABLE
ora.asmnet1.asmnetwork(ora.asmgroup)
1 ONLINE ONLINE db193 STABLE
2 ONLINE ONLINE db195 STABLE
ora.cvu
1 ONLINE ONLINE db193 STABLE
ora.db193.vip
1 ONLINE ONLINE db193 STABLE
ora.db195.vip
1 ONLINE ONLINE db195 STABLE
ora.jydb.cmdb1.svc
2 ONLINE ONLINE db193 STABLE
ora.jydb.db
1 ONLINE ONLINE db193 Open,HOME=/u01/app/o
racle/product/19.3.0
/db_1,STABLE
2 ONLINE ONLINE db195 Open,HOME=/u01/app/o
racle/product/19.3.0
/db_1,STABLE
ora.qosmserver
1 ONLINE ONLINE db193 STABLE
ora.scan1.vip
1 ONLINE ONLINE db193 STABLE
--------------------------------------------------------------------------------
[grid@db193 ~]$
这样看起来就像11g RAC集群那样很简洁了。
此时查询配置，确认当前ASM配置实例数量为ALL（当然如果你之前修改时指定2那这里也会显示是2）：
[grid@db193 ~]$ srvctl config asm
ASM home: <CRS home>
Password file: +CRS/orapwASM
Backup of Password file: +CRS/orapwASM_backup
ASM listener: LISTENER
ASM instance count: ALL
Cluster ASM listener: ASMNET1LSNR_ASM
[grid@db193 ~]$ asmcmd showclustermode
ASM cluster : Flex mode enabled - Direct Storage Access