下文内容皆为虚拟机实验环境模拟。

新建磁盘组：

1.查看磁盘情况： fdisk -l

Disk /dev/sda: 107.4 GB, 107374182400 bytes, 209715200 sectors

Disk /dev/sdb: 16.1 GB, 16106127360 bytes, 31457280 sectors

Disk /dev/sdc: 26.8 GB, 26843545600 bytes, 52428800 sectors

Disk /dev/sdd: 5368 MB, 5368709120 bytes, 10485760 sectors

2.查看磁盘的wwid

for i in `cat /proc/partitions | awk '{print $4}' |grep sd | grep [a-z]$`; do echo "### $i: ` /usr/lib/udev/scsi_id -g -u -d /dev/$i`"; done

### sda: 1ATA_VBOX_HARDDISK_VBcbf2815f-97e0701b
### sdb: 1ATA_VBOX_HARDDISK_VB26d0cb2b-3af6a552
### sdc: 1ATA_VBOX_HARDDISK_VB9beff7cc-286da8c0
### sdd: 1ATA_VBOX_HARDDISK_VB3e25be20-22d544de

3.查看已挂载磁盘的属组和权限： ll /dev/raw

ll /dev/raw
total 0
brw-rw---- 1 grid asmadmin 8, 16 Mar 15 09:29 raw1
brw-rw---- 1 grid asmadmin 8, 32 Mar 15 09:29 raw2
crw-rw---- 1 root disk 162, 0 Mar 15 09:29 rawctl

4.修改rules文件，将新的wwid加入到文件中，并使其生效（两个节点都要做）

vi /etc/udev/rules.d/99-oracle-asmdevices.rules

KERNEL=="sd*[!0-9]", ENV{DEVTYPE}=="disk", SUBSYSTEM=="block", PROGRAM=="/usr/lib/udev/scsi_id -g -u -d $devnode", RESULT=="1ATA_VBOX_HARDDISK_VB26d0cb2b-3af6a552", RUN+="/bin/sh -c 'mknod /dev/raw/raw1 b $major $minor; chown grid:asmadmin /dev/raw/raw1; chmod 0660 /dev/raw/raw1'"
KERNEL=="sd*[!0-9]", ENV{DEVTYPE}=="disk", SUBSYSTEM=="block", PROGRAM=="/usr/lib/udev/scsi_id -g -u -d $devnode", RESULT=="1ATA_VBOX_HARDDISK_VB9beff7cc-286da8c0", 

RUN+="/bin/sh -c 'mknod /dev/raw/raw2 b $major $minor; chown grid:asmadmin /dev/raw/raw2; chmod 0660 /dev/raw/raw2'"
KERNEL=="sd*[!0-9]", ENV{DEVTYPE}=="disk", SUBSYSTEM=="block", PROGRAM=="/usr/lib/udev/scsi_id -g -u -d $devnode", RESULT=="1ATA_VBOX_HARDDISK_VB3e25be20-22d544de", RUN+="/bin/sh -c 'mknod /dev/raw/raw3 b $major $minor; chown grid:asmadmin /dev/raw/raw3; chmod 0660 /dev/raw/raw3'"

使用命令： /sbin/udevadm trigger --type=devices --action=change 使其生效，使用： ll /dev/raw 查看属组和权限

total 0
brw-rw---- 1 grid asmadmin 8, 16 Mar 15 09:29 raw1
brw-rw---- 1 grid asmadmin 8, 32 Mar 15 09:29 raw2
brw-rw---- 1 grid asmadmin 8, 48 Mar 15 09:48 raw3
crw-rw---- 1 root disk 162, 0 Mar 15 09:48 rawctl

5.检查COMPATIBILITY,DATABASE_COMPATIBILITY参数：select NAME,COMPATIBILITY,DATABASE_COMPATIBILITY from v$asm_diskgroup;

NAME COMPATIBILITY DATABASE_COMPATIBILITY
--------------- ------------------------- -------------------------
CRS 19.0.0.0.0 10.1.0.0.0
DATA 19.0.0.0.0 10.1.0.0.0
DATADG 19.0.0.0.0 10.1.0.0.0

6.切换grid用户，登录asm实例，并创建新的磁盘组

[root@rac1 ~]# su - grid
Last login: Tue Mar 15 09:50:44 CST 2022
[grid@rac1:/home/grid]$ sqlplus / as sysasm

SQL*Plus: Release 19.0.0.0.0 - Production on Tue Mar 15 09:53:00 2022
Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle. All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

create diskgroup DATADG external redundancy disk

 '/dev/raw/raw3'

 attribute 'compatible.asm' ='19.0.0.0.0','compatible.rdbms'='10.1.0.0.0';

Diskgroup created.

磁盘组扩容：

1.将刚刚新增的DATADG磁盘组dismount，删除。

dismount: alter diskgroup DATADG dismount;

drop: drop diskgroup DATADG force including contents;

2.将空闲磁盘添加到原有的DATA上，可在另一个节点查看rebalance进度。

 加存储： 

alter diskgroup DATA add disk
'/dev/raw/raw3'
rebalance power 1;

查看进度：  

set linesize 160

select * from gv$asm_operation;（没有结果表明rebalance已完成）

下图可以看到DATA盘存储增加了5G。