v7000 lun 扩展 oracle asm,【ASM】ASMLIB 系列-- oracleasm

【ASM】ASMLIB 系列

说明：RHEL6、

RHEL7、CentOS6、CentOS7 都可以使用asmlib，只不过需要安装kmod-oracleasm包。

RHEL5不需要安装

kmod-oracleasm包

。

下载地址可直接在官网搜索：www.oracle.com

---------------------------- oracleasm常用命令  asmlib  oracleasm日志：　tail -f /var/log/oracleasm

/usr/sbin/oracleasm configure -i

/usr/sbin/oracleasm createdisk DISK1 /dev/sdb1

/etc/init.d/oracleasm scandisks

/etc/init.d/oracleasm listdisks

/etc/init.d/oracleasm enable

/etc/init.d/oracleasm restart

/etc/init.d/oracleasm status

/etc/init.d/oracleasm init

/usr/sbin/oracleasm enable

/usr/sbin/oracleasm restart

/usr/sbin/oracleasm createdisk DISKNAME devicename

/usr/sbin/oracleasm deletedisk DISKNAME

/usr/sbin/oracleasm querydisk {DISKNAME | devicename}

/usr/sbin/oracleasm listdisks

/usr/sbin/oracleasm scandisks

ls -l /dev/oracleasm/disks

--asmlib配置文件

cat /etc/sysconfig/oracleasm

oracleasm configure

oracleasm日志：　tail -f /var/log/oracleasm

安装：

## 先安装kmod-oracleasm，再安装oracleasmlib和oracleasm-support

--------------- rhel6.5安装asmlib：https://www.oracle.com/search

yum install -y kmod-oracleasm

# http://rpmfind.net/linux/rpm2html/search.php

# wget http://rpmfind.net/linux/centos/6.10/updates/x86_64/Packages/kmod-oracleasm-2.0.8-16.1.el6_10.x86_64.rpm

下载：https://www.oracle.com/linux/downloads/linux-asmlib-rhel6-downloads.html

wget https://oss.oracle.com/projects/oracleasm-support/dist/files/RPMS/rhel6/amd64/2.1.8/oracleasm-support-2.1.8-1.el6.x86_64.rpm

wget https://download.oracle.com/otn_software/asmlib/oracleasmlib-2.0.4-1.el6.x86_64.rpm

rpm -ivh *.rpm

oracleasm configure -i  # grid,asmadmin,y,y

oracleasm configure -d

oracleasm configure -e

oracleasm init

oracleasm status

fdisk -l | grep dev

oracleasm createdisk ocr01 /dev/vdb1

oracleasm listdisks

oracleasm renamedisk -f /dev/sdf1 asmdisk3

https://download.oracle.com/otn_software/asmlib/oracleasmlib-2.0.4-1.el6.x86_64.rpm

--------------- rhel7安装asmlib：https://www.oracle.com/search

yum install -y kmod-oracleasm

# http://rpmfind.net/linux/rpm2html/search.php

# wget http://rpmfind.net/linux/centos/7.7.1908/os/x86_64/Packages/kmod-oracleasm-2.0.8-26.el7.x86_64.rpm

下载：https://www.oracle.com/linux/downloads/linux-asmlib-rhel7-downloads.html

wget https://yum.oracle.com/repo/OracleLinux/OL7/latest/x86_64/getPackage/oracleasm-support-2.1.11-2.el7.x86_64.rpm

wget https://download.oracle.com/otn_software/asmlib/oracleasmlib-2.0.12-1.el7.x86_64.rpm

rpm -ivh *.rpm

systemctl enable oracleasm.service

oracleasm configure -i  # grid,asmadmin,y,y

oracleasm configure -d

oracleasm configure -e

oracleasm init

oracleasm status

fdisk -l | grep dev

oracleasm createdisk ocr01 /dev/vdb1

oracleasm listdisks

oracleasm renamedisk -f /dev/sdf1 asmdisk3

------ ASM磁盘

$ORACLE_HOME/bin/kfod disk=asm s=true ds=true c=true

/grid/stage/ext/bin/kfod disk=asm s=true ds=true c=true

# 18c

kfod disks=asm  ds=true cluster=true

create diskgroup DATA  external redundancy disk '/dev/raw/raw*';

create diskgroup FRA  external redundancy disk '/dev/rhdisk3';  --创建磁盘组FRA

CREATE DISKGROUP ACFSDG external redundancy DISK '/dev/oracleasm/disks/VOL1' ATTRIBUTE 'compatible.asm' = '11.2','compatible.rdbms' = '11.2','compatible.advm'='11.2';

create diskgroup OCR external redundancy disk 'ORCL:OVDISK' attribute 'compatible.asm'='11.2','compatible.rdbms'='11.2';

CREATE DISKGROUP dgroup1 NORMAL REDUNDANCY  disk '/dev/raw/raw6', '/dev/raw/raw7';

CREATE DISKGROUP dgroup1 HIGH REDUNDANCY  disk '/dev/raw/raw6', '/dev/raw/raw7', '/dev/raw/raw8';

create diskgroup DG1 external  redundancy

failgroup FG1 disk '/dev/raw/raw6' name DG2_FG1_VOL1

failgroup FG2 disk '/dev/raw/raw7' name DG2_FG2_VOL2;

create diskgroup DG2 normal redundancy

failgroup FG1 disk '/dev/raw/raw6' name DG2_FG1_VOL1

failgroup FG2 disk '/dev/raw/raw7' name DG2_FG2_VOL2;

create diskgroup DG2 normal redundancy

failgroup FG1 disk '/dev/raw/raw6','/dev/raw/raw7' name DG2_FG1_VOL1

failgroup FG2 disk '/dev/raw/raw8','/dev/raw/raw9' name DG2_FG2_VOL2;

---修改磁盘组的兼容属性

ALTER DISKGROUP asm_dg SET ATTRIBUTE 'compatible.asm' = '11.1';

ALTER DISKGROUP asm_dg SET ATTRIBUTE 'compatible.rdbms' = '11.1';

COLUMN name FORMAT A10

COLUMN compatibility FORMAT A20

COLUMN database_compatibility FORMAT A20

SELECT group_number, name, compatibility, database_compatibility FROM v$asm_diskgroup;

set line 9999

set pagesize 9999

col path format a60

SELECT a.group_number, disk_number,mount_status, a.name, path FROM v$asm_disk a order by a.disk_number;

select instance_name,status from v$instance;

set line 999

select name,state,free_mb,required_mirror_free_mb,usable_file_mb,a.group_number, disk_number,mount_status, path from v$asm_diskgroup a;

select a.group_number,name,TYPE,state,TOTAL_MB,free_mb from v$asm_diskgroup a;

select name,state,free_mb,required_mirror_free_mb,usable_file_mb,a.group_number from v$asm_diskgroup a;

alter diskgroup DG1 mount;

---nomount状态下强制删除磁盘组

drop diskgroup oradg force including contents;

alter diskgroup DG1 drop disk DG1_VOL5;   --删除磁盘组DG1中的磁盘VOL5

alter system set asm_diskstring='','ORCL:*','/dev/raw/raw*','/dev/oracleasm/disks/VOL*';

alter system set asm_diskstring='/dev/asm-disk*','/dev/raw/raw*';

alter diskgroup DATA add disk '/dev/raw/raw1';

export GRID_HOME=$ORACLE_HOME

# 查询ASM磁盘

$GRID_HOME/bin/kfod disks=asm  st=true ds=true cluster=true

# /grid/stage/ext/bin/kfod disks=asm  st=true ds=true cluster=true

------------------------ faking asmdisk asm磁盘

---- 添加loop设备个数

第一种办法：修改 /etc/modprobe.conf 文件添加参数：options loop max_loop=20 可以通过 modprobe -v loop 命令立即加载该模块，或重启

第二种办法(通用)：mknod -m 0660 /dev/loopX b 7 X

raw -qa

losetup -a

--mknod -m 0660 /dev/loopX b 7 X

mknod -m 0660 /dev/loop9 b 7 9

mkdir /asmdisk

dd if=/dev/zero of=/asmdisk/disk1 bs=1024k count=2000

dd if=/dev/zero of=/asmdisk/disk2 bs=1024k count=2000

dd if=/dev/zero of=/asmdisk/disk3 bs=1024k count=2000

dd if=/dev/zero of=/asmdisk/disk4 bs=1024k count=2000

dd if=/dev/zero of=/asmdisk/disk5 bs=1024k count=2000

/sbin/losetup /dev/loop1 /asmdisk/disk1

/sbin/losetup /dev/loop2 /asmdisk/disk2

/sbin/losetup /dev/loop3 /asmdisk/disk3

/sbin/losetup /dev/loop4 /asmdisk/disk4

/sbin/losetup /dev/loop5 /asmdisk/disk5

raw /dev/raw/raw1 /dev/loop1

raw /dev/raw/raw2 /dev/loop2

raw /dev/raw/raw3 /dev/loop3

raw /dev/raw/raw4 /dev/loop4

raw /dev/raw/raw5 /dev/loop5

chmod 660 /dev/raw/raw1

chmod 660 /dev/raw/raw2

chmod 660 /dev/raw/raw3

chmod 660 /dev/raw/raw4

chmod 660 /dev/raw/raw5

chown oracle:dba /dev/raw/raw1

chown oracle:dba /dev/raw/raw2

chown oracle:dba /dev/raw/raw3

chown oracle:dba /dev/raw/raw4

chown oracle:dba /dev/raw/raw5

------ 将以下内容添加到文件/etc/rc.local文件中

------Add the following entries to the file "/etc/rc.local"

/sbin/losetup /dev/loop1 /asmdisk/disk1

/sbin/losetup /dev/loop2 /asmdisk/disk2

/sbin/losetup /dev/loop3 /asmdisk/disk3

/sbin/losetup /dev/loop4 /asmdisk/disk4

/sbin/losetup /dev/loop5 /asmdisk/disk5

raw /dev/raw/raw1 /dev/loop1

raw /dev/raw/raw2 /dev/loop2

raw /dev/raw/raw3 /dev/loop3

raw /dev/raw/raw4 /dev/loop4

raw /dev/raw/raw5 /dev/loop5

chmod 660 /dev/raw/raw1

chmod 660 /dev/raw/raw2

chmod 660 /dev/raw/raw3

chmod 660 /dev/raw/raw4

chmod 660 /dev/raw/raw5

chown grid:asmadmin /dev/raw/raw1

chown grid:asmadmin /dev/raw/raw2

chown grid:asmadmin /dev/raw/raw3

chown grid:asmadmin /dev/raw/raw4

chown grid:asmadmin /dev/raw/raw5

------------------------ Simulating Asm by faking hardware

-->Faking Hardware

-->Instaling ASM Lib

-->Configuring the disks

-->Install DB & ASM instance

---Faking Hardware: root 用户

mkdir /asmdisk

dd if=/dev/zero of=/asmdisk/disk1 bs=1024k count=2000

dd if=/dev/zero of=/asmdisk/disk2 bs=1024k count=2000

/sbin/losetup /dev/loop1 /asmdisk/disk1

/sbin/losetup /dev/loop2 /asmdisk/disk2

raw /dev/raw/raw1 /dev/loop1

raw /dev/raw/raw2 /dev/loop2

chmod 660 /dev/raw/raw1

chmod 660 /dev/raw/raw2

chown grid:asmadmin /dev/raw/raw1

chown grid:asmadmin /dev/raw/raw2

------Add the following entries to the file "/etc/rc.local"

echo "/sbin/losetup /dev/loop1 /asmdisk/disk1" >>/etc/rc.local

echo "/sbin/losetup /dev/loop2 /asmdisk/disk2" >>/etc/rc.local

faking出来的磁盘也可以用于ASMLIB

# mknod -m 0660 /dev/loop3 b 7 3

# losetup -d loop1  #删除loop设备

losetup -a

mkdir /asmdisk

dd if=/dev/zero of=/asmdisk/disk1 bs=1024k count=2000

dd if=/dev/zero of=/asmdisk/disk2 bs=1024k count=2000

dd if=/dev/zero of=/asmdisk/disk3 bs=1024k count=2000

/sbin/losetup /dev/loop1 /asmdisk/disk1

/sbin/losetup /dev/loop2 /asmdisk/disk2

/sbin/losetup /dev/loop3 /asmdisk/disk3

oracleasm createdisk ASM1 /dev/loop1

oracleasm createdisk ASM2 /dev/loop2

oracleasm createdisk ASM3 /dev/loop3

----以下内容加入到/etc/rc.local

/sbin/losetup /dev/loop1 /asmdisk/disk1

/sbin/losetup /dev/loop2 /asmdisk/disk2

/sbin/losetup /dev/loop3 /asmdisk/disk3

oracleasm scandisks

# linux7下需要执行chmod +x /etc/rc.d/rc.local

使用ASMLIB管理磁盘

在存储管理员给服务器提供磁盘设备后，它们对于服务器来说是可用的并且可以在Linux系统中 的/proc/partitions虚拟文件中可以看到。系统管理然后使用Linux fdisk工具来对磁盘设备进行分 区。被分区后磁盘设备现在可以被配置为ASMLIB磁盘，系统管理员创建ASMLIB磁盘。创建命 令:oracleasm createdisk。createdisk命令使用两个输入参数，通过设备来生成用户定义的磁盘名:

[root@racnode1]#/etc/init.d/oracleasm createdisk VOL1 /dev/sdg1

Creating Oracle ASM disk "VOL1" [ OK ]

磁盘名被限制为30个字符。它们必须使用字母开头但可以由其它ASCII字符组成，包括：大写字母， 数字和下划线。每一个被创建成功的磁盘被标识为ASMLIB磁盘并且会被显示在oracleasm文件系统 中/dev/oracleasm/disks/。文件系统是一种特定的不受任何方式进行维护。

用户可查询磁盘设备来判断是否它们是有效的ASMLIB磁盘。为了查询，使用下面的oracleasm querydisk命令。querydisk命令可以应用于裸设备和ASMLIB磁盘

[root@racnode1]#/etc/init.d/oracleasm querydisk /dev/sdg1

Checking if device "/dev/sdg" is an Oracle ASM disk [ OK ]

[root@racnode1]#/etc/init.d/oracleasm querydisk VOL1

Checking for ASM disk "VOL1" [ OK ]

另外，所有被标记的磁盘与使用ASMLIB创建的磁盘可以使用以下oracleasm listdisks命令来显示:

[root@racnode1]#/etc/init.d/oracleasm listdisks

VOL1

VOL2

VOL3

如果一个磁盘设备不是一个ASMLIB磁盘，会显示以下信息:

[root@racnode1]#/etc/init.d/oracleasm querydisk /dev/sdh1

Checking if device "/dev/sdh1" is an Oracle ASM disk [FAILED]

对于ASM不再需要的磁盘可以撤消标记并且使用oracleasm deletedisk命令来删除:

[root@racnode1]#/etc/init.d/oracleasm deletedisk VOL1

Deleting Oracle ASM disk "VOL1" [ OK ]

当ASMLIB用于RAC环境时，对于RAC的共享磁盘架构允许使用oracleasm createdisk命令只在一个节点 上创建ASMLIB磁盘，其它节点只需要使用ASMLIB扫描来查找ASMLIB磁盘就可以了。例如，对于两节点 RAC环境，节点1可以标记ASMLIB磁盘，节点2然后执行扫描ASMLIB磁盘来查找这些ASMLIB磁盘。

[root@racnode1]#/etc/init.d/oracleasm createdisk VOL1 /dev/sdg1

Creating Oracle ASM disk "VOL1" [ OK ]

[root@racnode2]#/etc/init.d/oracleasm scandisks

Scanning system for ASM disks [ OK ]

在合适的ASMLIB磁盘创建后，ASM的init.ora参数asm_diskstring可以保留缺省的NULL或者设置 为'ORCL:*'。一旦设置后，ASM将可以发现以下磁盘:

SQL> select name, library, path from v$asm_disk;

NAME        LIBRARY                   PATH

----------- ------------------------- -------------------------

VOL1        ASM Library Generic Linux ORCL:VOL1

VOL2        ASM Library Generic Linux ORCL:VOL2

VOL3        ASM Library Generic Linux ORCL:VOL3

注意，如果ASMLIB没有使用，那么上面的查询LIBRARY列将返回"System"。

重命名Disk

renamedisk命令被用来改变现有成员的标签而不会丢失数据。注意修改磁盘时只有当ASM不访问该磁 盘才行。因此磁盘组必须dismount，并且在RAC环境中，所有ASM节点必须都dismount磁盘组。当有 ASM实例访问被重新标签的磁盘时执行renamedisk操作可能造成损坏。因为renamedisk命令是危险的 通过打印消息可以看到:

[root@racnode1]#/etc/init.d/oracleasm renamedisk /dev/sdb3 VOL1

Warning: Changing the label of a disk marked for ASM is a very

dangerous operation. If this is really what you mean to do, you

must ensure that all Oracle and ASM instances have ceased using

this disk. Otherwise, you may LOSE DATA. If you really wish to

change the label, rerun with the force-renamedisk command.

[root@racnode1]#/etc/init.d/oracleasm force-renamedisk /dev/sdb3 VOL1

Renaming disk "/dev/sdb3" to "VOL1" [ OK ]

force_renamedisk命令使用两个参数:裸设备名，其次是ASM磁盘名。

discover磁盘

命令/sbin/oracleasm-discover是一个简单的工具来判断Oracle的Linux ASMLIB在discover操作时所看到那个磁盘。这个命令更多一个调试工具来验证discover所列出的请求磁盘。这个命令也列出了每个磁盘的最大I/O大小。最大I/O大小，ASMLIB可以作为一个命令发送给设备。

[root@racnode1]#/usr/sbin/oracleasm-discover 'ORCL:*'

Using ASMLib from /opt/oracle/extapi/32/asm/orcl/1/libasm.so

[ASM Library - Generic Linux, version 2.0.0 (KABI_V1)]

Discovered disk: ORCL:VOL1 [819200 blocks (419430400 bytes), maxio 512]

Discovered disk: ORCL:VOL2 [1955808 blocks (1001373696 bytes), maxio 512]

最大I/O大小来自SCSI HBA设备与磁盘设备链中的其它设备。在上面的例子中，maxio等于512,512 byte或256K。如果maxio显示了最小值，比如128，那么它可能是中间组件比如多路径设备或HBA设备限制的原因。

升级ASMLIB

为了升级ASMLIB，系统管理员可以执行以下步骤。注意这是严格意义上的软件升级并且没有磁盘标签 被维护。这是一个节点本地升级，因此在RAC环境中，每个单独的节点应该被升级。

1.关闭ASM

2.执行/etc/init.d/oracleasm stop

3.执行rpm -Uvh oracleasm-*.rpm

4.执行/etc/init.d/oracleasm start

5.启动ASM

诊断ASMLIB

诊断ASMLIB从上到下的操作步骤为:

1.使用的Oracle ASMLIB的当前版本。验证软件版本。ASMLIB请求一个设备精确匹配给内核，因此使 用与uname -a命令输出匹配的oracleasm内核包。

[root@racnode1]# rpm -qa |grep oracleasm

oracleasm-support-2.0.3-1.i386.rpm

oracleasmlib-2.0.2-1.i386.rpm

oracleasm-2.6.9-42.0.3.ELsmp-2.0.3-1.i686.rpm

[root@racnode1]# uname -a

Linux racnode1.us.oracle.com 2.6.9-42.0.3.ELsmp #1Thu May 15

17:03:45 EST 2006 i686 i686 i386 GNU/Linux

2.验证ASMLIB的安装设置

3.确保oracleasm configure命令正确运行，使用以下信息进行确认配置:

a.以root用户执行lsmod命令来显示加载的oracleasm模块。使用oracleasm模块"Used by"列会被设 置为1.

[root@db2 ~]# lsmod

Module                  Size  Used by

oracleasm              53591  1

8021q                  20994  0

garp                    7297  1 8021q

stp                     2256  1 garp

llc                     5608  2 garp,stp

cpufreq_ondemand        9398  80

ip6t_REJECT             4486  2

nf_conntrack_ipv6      10595  3

nf_defrag_ipv6         11368  1 nf_conntrack_ipv6

xt_state                1370  3

nf_conntrack           84658  2 nf_conntrack_ipv6,xt_state

ip6table_filter         1671  1

ip6_tables             19409  1 ip6table_filter

ipv6                  339024  660 ip6t_REJECT,nf_conntrack_ipv6,nf_defrag_ipv6

dm_round_robin          2531  34

dm_multipath           18562  18 dm_round_robin

uinput                  8917  0

sg                     30968  0

serio_raw               5631  0

iTCO_wdt                6353  0

iTCO_vendor_support     3030  1 iTCO_wdt

coretemp                6997  0

acpi_cpufreq           13345  0

freq_table              6987  2 cpufreq_ondemand,acpi_cpufreq

mperf                   1555  1 acpi_cpufreq

intel_powerclamp       10841  0

kvm_intel             130025  0

kvm                   438077  1 kvm_intel

crc32c_intel           14496  0

ghash_clmulni_intel     4707  0

microcode             115607  0

pcspkr                  2150  0

igb                   186225  0

hwmon                   2087  2 coretemp,igb

i2c_i801               12911  0

i2c_core               31228  1 i2c_i801

lpc_ich                12496  0

mfd_core                3955  1 lpc_ich

ioatdma                61937  168

dca                     7283  2 igb,ioatdma

i7core_edac            20072  0

edac_core              54168  1 i7core_edac

shpchp                 27901  0

ext4                  532546  2

jbd2                  100769  1 ext4

mbcache                 7575  1 ext4

sd_mod                 41045  38

crc_t10dif              1547  1 sd_mod

qla2xxx               562439  68

scsi_transport_fc      54538  1 qla2xxx

scsi_tgt               12075  1 scsi_transport_fc

sr_mod                 15980  0

cdrom                  40900  1 sr_mod

usb_storage            53806  0

megaraid_sas          101114  3

aesni_intel            45744  0

ablk_helper             2997  1 aesni_intel

cryptd                 10460  3 ghash_clmulni_intel,aesni_intel,ablk_helper

lrw                     4222  1 aesni_intel

aes_x86_64              7967  1 aesni_intel

xts                     3466  1 aesni_intel

gf128mul                7999  2 lrw,xts

pata_acpi               3782  0

ata_generic             3758  0

ata_piix               26525  0

dm_mirror              14208  0

dm_region_hash         11094  1 dm_mirror

dm_log                  9681  2 dm_mirror,dm_region_hash

dm_mod                 85047  41 dm_multipath,dm_mirror,dm_log

b.执行命令cat /proc/filesystem，并且确保在文件系统列表中存在一条名叫oracleasmfs的记录:

[root@db2 ~]# cat /proc/filesystems

nodev   sysfs

nodev   rootfs

nodev   bdev

nodev   proc

nodev   cgroup

nodev   cpuset

nodev   tmpfs

nodev   devtmpfs

nodev   binfmt_misc

nodev   debugfs

nodev   securityfs

nodev   sockfs

nodev   pipefs

nodev   anon_inodefs

nodev   devpts

nodev   ramfs

nodev   hugetlbfs

iso9660

nodev   pstore

nodev   mqueue

ext4

nodev   asmdisk

nodev   oracleasmfs

c.执行命令 df -ha，它将显示所mount的oracleasmfs

/dev/mapper/vg_db2-LogVol00

1.1T  437G  592G  43% /

proc                     0     0     0    - /proc

sysfs                    0     0     0    - /sys

devpts                   0     0     0    - /dev/pts

tmpfs                 126G 1005M  125G   1% /dev/shm

/dev/sda1             190M   79M   98M  45% /boot

none                     0     0     0    - /proc/sys/fs/binfmt_misc

oracleasmfs              0     0     0    - /dev/oracleasm

确保oracleasm createdisk正确执行。为了让ASM使用，磁盘被通过createdisk命令来标记。当磁盘被标记后，会在磁盘头中写入签名--，磁盘将被标记ASM使用。可以使用以下命令来验证.执行oracleasm listdisks命令。这个命令将显示被标记为ASMLIB的磁盘。

[root@db2 ~]# oracleasm listdisks

ARCH0

ARCH1

ARCH2

ARCH3

CW_DATA1

OCR1

OCR2

OCR3

RLZY_ARCH1

RLZY_DATA1

RLZY_DATA2

RLZY_DATA3

SBK_DATA0

SBK_DATA1

SBK_DATA2

YB_DATA4

YB_DATA5

.对每个被标记为ASMLIB磁盘执行oracleasm querydisk命令来确保标记

[root@db2 ~]# oracleasm querydisk YB_DATA4

Disk "YB_DATA4" is a valid ASM disk

4.执行ls -l /dev/oracleasm/disks来确保磁盘的所属组与权限是grid:asmadmin

[root@db2 ~]# ls -l /dev/oracleasm/disks

total 0

brw-rw---- 1 grid asmadmin 252,  8 Dec  7 20:14 ARCH0

brw-rw---- 1 grid asmadmin 252,  9 Dec  7 20:17 ARCH1

brw-rw---- 1 grid asmadmin 252, 10 Dec  7 20:18 ARCH2

brw-rw---- 1 grid asmadmin 252, 11 Dec  7 20:18 ARCH3

brw-rw---- 1 grid asmadmin 252, 14 Dec  7 20:18 CW_DATA1

brw-rw---- 1 grid asmadmin 252,  1 Dec  7 20:18 OCR1

brw-rw---- 1 grid asmadmin 252,  2 Dec  7 20:18 OCR2

brw-rw---- 1 grid asmadmin 252,  6 Dec  7 20:18 OCR3

brw-rw---- 1 grid asmadmin 252,  7 Dec  7 20:18 RLZY_ARCH1

brw-rw---- 1 grid asmadmin 252,  3 Dec  7 20:18 RLZY_DATA1

brw-rw---- 1 grid asmadmin 252,  4 Dec  7 20:18 RLZY_DATA2

brw-rw---- 1 grid asmadmin 252,  5 Dec  7 20:18 RLZY_DATA3

brw-rw---- 1 grid asmadmin 252, 15 Dec  7 20:18 SBK_DATA0

brw-rw---- 1 grid asmadmin 252, 16 Dec  7 20:18 SBK_DATA1

brw-rw---- 1 grid asmadmin 252, 17 Dec  7 20:18 SBK_DATA2

brw-rw---- 1 grid asmadmin 252, 12 Dec  7 20:18 YB_DATA4

brw-rw---- 1 grid asmadmin 252, 13 Dec  7 20:18 YB_DATA5

5.验证ASMLIB发现字符串(可以在DBCA中指定或设置asm_diskstring参数)是否被设置ORCL:*或NULL。 如果ASM实例在运行，那么检查ASM的alert log查看是否正确设置。

6.对ASM alert log中关于发现所显示的任何信息使用Linux/Unix的grep命令。如果成功加载ASMLIB 将会显示以下信息:

Loaded ASM Library - Generic Linux, version 2.0.1 library for

ASMLIB interface

下面的查询显示被发现的ASMLIB磁盘:

SQL> SELECT LIBRARY, PATH FROM V$ASM_DISK;

LIBRARY                                     PATH

------------------------------------------- ----------------

ASM Library - Generic Linux, version 2.0.0.1 ORCL:VOL1

ASM Library - Generic Linux, version 2.0.0.1 ORCL:VOL2

ASM Library - Generic Linux, version 2.0.0.1 ORCL:VOL3

如果在Library列显示system，那么asm_diskstring没有设备--，ASMLIB不能用于访问磁盘。ASMLIB 需要通过磁盘符ORCL:*来访问磁盘。检查asm_diskstring是否设置为ORCL:*或NULL:

SQL> SELECT LIBRARY, PATH FROM V$ASM_DISK;

LIBRARY        PATH

-------------- -------------------------------------------------

System         /dev/oracleasm/disks/DATA1D1

System         /dev/oracleasm/disks/DATA1D2

System         /dev/oracleasm/disks/DATA1D3

7.查看ASM alert log中是否有以下错误信息:

ORA-15186: ASMLIB error function = [asm_open], error = [1],mesg = [Operation not  permitted]

这个消息通常意味着在/etc/init.d/oracleasm configure操作时ASMLIB配置权限不正确

迁移到ASMLIB

在许多情况下可能需要将一个"member"ASM裸磁盘转换为一个ASMLIB磁盘。例如，当安装ASMLIB后需 要执行。相反，如果需要卸载ASMLIB,可以将一个ASMLIB磁盘转换为一个标准的ASM磁盘。所有这种操 作不会损坏磁盘上的数据。然而，在转换之前必须将磁盘组dismount。

这种转换不会损坏数据因为磁盘上的结构和磁盘打开ASM所读取的信息。ASM读取磁盘头并且识别它属 于那个磁盘组。当一个磁盘被增加到一个磁盘组时，ASM将对磁盘写入一些信息。两个重要的条目是 磁盘标记与ASMLIB标签。所有ASM磁盘有一个标记ORCLSDISK印记在磁盘上面。如果标记已经存在，那 么磁盘可以当前被使用或者被ASM格式化了。这个标记可以由ASM或ASMLIB所创建。例如，当ASM在创 建磁盘组时使用一个磁盘作为一个裸设备时，ASM会自动增加这个标记。相反，当通过ASMLIB命 令/etc/init.d/oracleasm createdisk命令时磁盘会增加ASMLIB标记。不管使用那种工具创建标记， 一旦标记被创建，磁盘就会被打上标签。

磁盘头的第二部分与ASMLIB相关，是ASMLIB标签。这是指派给ASMLIB用来标识磁盘的24个字符的字符 串。当通过ASMLIB的/etc/init.d/oracleasm createdisk命令来配置磁盘时，相关的标签会被写入设备。注意ASM会保存磁盘的内容，但写入这部分信息是留给ASMLIB。

下面是一个对ASM磁盘(不是ASMLIB)的一个简单dump，这个磁盘被加入一个磁盘。在磁盘头中的ASM磁 盘名为DATA_0003:

[root@db2 ~]# dd if=/dev/mapper/yb_data4 bs=128 count=1 | od -a

1+0 records in

1+0 records out

0000000 soh stx soh soh nul nul nul nul etx nul nul nul   K eot   [   l

128 bytes (128 B) copied0000020   N   d   ? nul nul nul nul nul nul nul nul nul nul nul  nul nul

, 0.000253206 s, 506 kB/s

0000040   O   R   C   L   D   I   S   K nul nul nul nul nul nul nul nul

0000060 nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul

0000100 nul nul  sp  vt etx nul soh etx   D   A   T   A   _   0   0   0

0000120   3 nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul

0000140 nul nul nul nul nul nul nul nul   D   A   T   A nul nul nul nul

0000160 nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul

0000200

[root@db2 ~]#

下面例子使对使用/etc/init.d/oracleasm createdisk命令所创建的ASMLIB磁盘进行一个简单的dump 注意YB_DATA4被写入ORCLDISK标签中:

[root@db2 ~]# oracleasm querydisk -v -p  YB_DATA4

Disk "YB_DATA4" is a valid ASM disk

/dev/sdn: LABEL="YB_DATA4" TYPE="oracleasm"

/dev/sdae: LABEL="YB_DATA4" TYPE="oracleasm"

/dev/mapper/yb_data4: LABEL="YB_DATA4" TYPE="oracleasm"

[root@db2 ~]# dd if=/dev/mapper/yb_data4 bs=128 count=1 | od -a

1+0 records in

1+0 records out

128 bytes (128 B) copied, 0.000204442 s, 626 kB/s

0000000 soh stx soh soh nul nul nul nul etx nul nul nul   K eot   [   l

0000020   N   d   ? nul nul nul nul nul nul nul nul nul nul nul nul nul

0000040   O   R   C   L   D   I   S   K   Y   B   _   D   A   T   A   4

0000060 nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul

0000100 nul nul  sp  vt etx nul soh etx   D   A   T   A   _   0   0   0

0000120   3 nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul

0000140 nul nul nul nul nul nul nul nul   D   A   T   A nul nul nul nul

0000160 nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul nul

0000200

在这个例子中，标记ORCLDISK与YB_DATA4被写入磁盘头。下面ASMLIB扫描磁盘时，它将查看标记 ORCLDISK与YB_DATA4，并使用YB_DATA创建一个ASMLIB磁盘到设备的映射。后续，ASM将通过ASMLIB驱 动来发现这个磁盘。如果磁盘最初没有通过ASMLIB管理，当ASM发现磁盘时，将通过ASM裸设备访问， 它将检测试没有ASMLIB标记存在。这就是为什么从ASMLIB访问迁移到裸设备来访问不存在问题的原因 。

使用ASMLIB与Multipath工具

多路径设备使用伪设备来生成虚拟子路径。在执行磁盘发现操作时，ASMLIB使用伪文 件/proc/partitions。这是一个Linux文件它记录了所有设备与之匹配的分区。

[root@db2 ~]# cat /proc/partitions

major minor  #blocks  name

11        0    1048575 sr0

11        1    1048575 sr1

8        0 1171062784 sda

8        1     204800 sda1

8        2   16777216 sda2

8        3 1154079744 sda3

8       64  629145600 sde

8       48   10485760 sdd

8       32   10485760 sdc

8       80  629145600 sdf

8       96  629145600 sdg

8      112   10485760 sdh

8      128  629145600 sdi

8      144  629145600 sdj

8      160  629145600 sdk

8      176  629145600 sdl

8      192  629145600 sdm

8      224  629145600 sdo

8      208  629145600 sdn

65        0  629145600 sdq

8      240  209715200 sdp

65       16  629145600 sdr

65       32  629145600 sds

65       48   10485760 sdt

65       64   10485760 sdu

65       80  629145600 sdv

65       96  629145600 sdw

65      112  629145600 sdx

65      128   10485760 sdy

65      144  629145600 sdz

65      160  629145600 sdaa

65      176  629145600 sdab

65      192  629145600 sdac

65      208  629145600 sdad

65      224  629145600 sdae

65      240  629145600 sdaf

66        0  209715200 sdag

66       16  629145600 sdah

66       32  629145600 sdai

66       48  629145600 sdaj

252        0 1154076672 dm-0

252        1   10485760 dm-1

252        2   10485760 dm-2

252        3  629145600 dm-3

252        4  629145600 dm-4

252        5  629145600 dm-5

252        6   10485760 dm-6

252        7  629145600 dm-7

252        8  629145600 dm-8

252        9  629145600 dm-9

252       10  629145600 dm-10

252       11  629145600 dm-11

252       12  629145600 dm-12

252       13  629145600 dm-13

252       14  209715200 dm-14

252       15  629145600 dm-15

252       16  629145600 dm-16

252       17  629145600 dm-17

为了让多路径正确工作，ASMLIB必须只能对伪设备操作。因此ASMLIB必须使用伪设备来进行修改。通 过修改/etc/sysconfig/oracleasm中的两个参数来进行配置:

.oracleasm_scanorder使用通用前缀指定ASMLIB扫描设备的顺序。

.oracleasm_scanexclude通过ASMLIB指定那个设备不被发现。

例如，使用IBM v7000与多路径配置ASMLIB进行如下设置:

ORACLEASM_SCANORDER="dm"

ORACLEASM_SCANEXCLUDE="sd"

在这个例子中，ASMLIB基于/dev/dm来扫描磁盘并且排除/dev/sd*的设备。下面 是/etc/sysconfig/oracleasm文件的一个配置例子:

[root@db2 ~]# cat /etc/sysconfig/oracleasm

#

# This is a configuration file for automatic loading of the Oracle

# Automatic Storage Management library kernel driver.  It is generated

# By running /etc/init.d/oracleasm configure.  Please use that method

# to modify this file

#

# ORACLEASM_ENABLED: 'true' means to load the driver on boot.

ORACLEASM_ENABLED=true

# ORACLEASM_UID: Default user owning the /dev/oracleasm mount point.

ORACLEASM_UID=grid

# ORACLEASM_GID: Default group owning the /dev/oracleasm mount point.

ORACLEASM_GID=asmadmin

# ORACLEASM_SCANBOOT: 'true' means scan for ASM disks on boot.

ORACLEASM_SCANBOOT=true

# ORACLEASM_SCANORDER: Matching patterns to order disk scanning

ORACLEASM_SCANORDER="dm"

# ORACLEASM_SCANEXCLUDE: Matching patterns to exclude disks from scan

ORACLEASM_SCANEXCLUDE="sd"

# ORACLEASM_USE_LOGICAL_BLOCK_SIZE: 'true' means use the logical block size

# reported by the underlying disk instead of the physical. The default

# is 'false'

ORACLEASM_USE_LOGICAL_BLOCK_SIZE=false

小结:

ASMLIB是Oracle 10g与11g中ASM功能的支持library。ASMLIB允许Oracle数据库更有效的使用ASM与访 问磁盘组。ASMLIB的目的，它是ASM的一个插件，提供了一种识别与访问块设备的替接口。另外， ASMLIB API能够让存储与操作系统厂商来提供存储相关的扩展功能。这些功能可能提供一些好处，比 如提高性能与增加完整性。但ASMLIB对于ASM不是必须使用的。

3.3.1.4

Configuring Disks for Oracle

ASM with ASMLIB

The Oracle Automatic Storage Management (Oracle ASM) library driver (ASMLIB)

simplifies the configuration and management of the disk devices by eliminating

the need to rebind disk devices used with Oracle ASM each time the system is

restarted.

Without ASMLIB Linux 2.6 kernel and later, block device paths do not maintain

permissions and path persistence unless you create a permissions or rules file on each cluster member node; block device paths that

were /dev/sda can appear as /dev/sdb after a system

restart. Adding new disks requires you to modify the udev file to

provide permissions and path persistence for the new disk.

With ASMLIB, you define the range of disks you want to have made available as

Oracle ASM disks. ASMLIB maintains permissions and disk labels that are

persistent on the storage device, so that label is available even after an

operating system upgrade. You can update storage paths on all cluster member

nodes by running one oracleasm command on each node.

If you intend to use Oracle ASM on block devices for database storage for

Linux, then Oracle recommends that you install the ASMLIB driver and associated

utilities, and use them to configure the disks for Oracle ASM.

Caution:

On IBM: Linux on System z servers, due to a block

size compatibility issue, you cannot use ASMLIB with SCSI storage devices and

Fibre Channel Protocol (FCP) for Oracle Grid Infrastructure release 11.2.0.1 and

later.

Workaround:

use block device directly (for example,

using paths similar to /dev/mapper/mpatha_part1), or use DASD

disks.

See Also:

My Oracle Support notes How to Manually Configure

Disk Storage devices for use with Oracle ASM 11.2 on IBM: Linux on System z

under SLES (Doc ID

1350008.1

)

and How to Manually Configure Disk Storage devices for use with Oracle ASM 11.2

on IBM: Linux on System z under Red Hat 5 (Doc ID

1351746.1

),

available at the following URL:

To use the Oracle Automatic Storage Management library driver (ASMLIB) to

configure Oracle ASM devices, complete the following tasks.

Note:

To create a database during the installation using the

Oracle ASM library driver, you must choose an installation method that runs

ASMCA in interactive mode. You must also change the default disk discovery

string to ORCL:*.

3.3.1.4.1

Installing and Configuring

the Oracle ASM Library Driver Software

ASMLIB is already included with Unbreakable Enterprise Kernel packages, and

with SUSE 11. If you are a member of the Unbreakable Linux Network, then you can

install the ASMLIB rpms by subscribing to the Oracle Software for Enterprise

Linux channel, and using up2date to retrieve the most current

package for your system and kernel. For additional information, refer to the

following URL:

http://www.oracle.com/technetwork/topics/linux/asmlib/index-101839.html

To install and configure the ASMLIB driver software manually, follow these

steps:

Enter the following command to determine the kernel version and architecture

of the system:

# uname -rm

Download the required ASMLIB packages from the Oracle Technology Network

(OTN) Web site:

http://www.oracle.com/technetwork/server-storage/linux/downloads/index-088143.html

Note:

You must install oracleasm-support package

version 2.0.1 or later to use ASMLIB on Red Hat Enterprise Linux 5 Advanced

Server. ASMLIB is already included with SUSE distributions.

Tip:

My Oracle Support note

1089399.1

for information about ASMLIB support with Red Hat distributions:

You must install the following packages, where version is the version of the ASMLIB

driver, arch is the system

architecture, and kernel is the

version of the kernel that you are using:

oracleasm-support-version.arch.rpm

oracleasm-kernel-version.arch.rpm

oracleasmlib-version.arch.rpm

Switch user to the root user:

$ su -

Enter a command similar to the following to install the packages:

# rpm -ivh oracleasm-support-version.arch.rpm \

oracleasm-kernel-version.arch.rpm \

oracleasmlib-version.arch.rpm

For example, if you are using the Red Hat Enterprise Linux 5 AS kernel on an

AMD64 system, then enter a command similar to the following:

# rpm -ivh oracleasm-support-2.1.3-1.el5.x86_64.rpm \

oracleasm-2.6.18-194.26.1.el5xen-2.0.5-1.el5.x86_64.rpm \

oracleasmlib-2.0.4-1.el5.x86_64.rpm

Enter the following command to run the oracleasm initialization script with the configure option:

# /usr/sbin/oracleasm configure -i

Note:

The oracleasm command in /usr/sbin is the command you should use. The /etc/init.d path is not deprecated, but the oracleasm binary in that path is now used typically for internal commands.

Enter the following information in response to the prompts that the script

displays:

Prompt

Suggested Response

Default user to own the driver

interface:

Standard groups and

users configuration

: Specify the Oracle software owner user (for example, oracle)

Job role separation groups and users configuration:

Specify the Grid Infrastructure software owner (for example, grid)

Default group to own the driver

interface:

Standard groups and

users configuration

: Specify the OSDBA group for the database (for

example, dba).

Job role separation groups and users configuration:

Specify the OSASM group for storage administration (for example, asmadmin).

Start Oracle ASM Library driver on

boot (y/n):

Enter y to start the

Oracle Automatic Storage Management library driver when the system

starts.

Scan for Oracle ASM disks on boot

(y/n)

Enter y to scan for

Oracle ASM disks when the system starts.

The script completes the following tasks:

Creates the /etc/sysconfig/oracleasm configuration file

Creates the /dev/oracleasm mount point

Mounts the ASMLIB driver file system

Note:

The ASMLIB driver file system is not a regular file

system. It is used only by the Oracle ASM library to communicate with the Oracle

ASM driver.

Enter the following command to load the oracleasm kernel

module:

# /usr/sbin/oracleasm init

Repeat this procedure on all nodes in the cluster where you want to install

Oracle RAC.

3.3.1.4.2

Configuring Disk Devices to

Use Oracle ASM Library Driver on x86 Systems

To configure the disk devices to use in an Oracle ASM disk group, follow

these steps:

If you intend to use IDE, SCSI, or RAID devices in the Oracle ASM disk group,

then follow these steps:

If necessary, install or configure the shared disk devices that you intend to

use for the disk group and restart the system.

To identify the device name for the disks to use, enter the following

command:

# /sbin/fdisk -l

Depending on the type of disk, the device name can vary:

Disk Type

Device Name Format

Description

IDE disk

/dev/hdxn

In this example, x is a letter that identifies the IDE disk

and n is the partition number.

For example, /dev/hda is the first disk on the first IDE

bus.

SCSI disk

/dev/sdxn

In this example, x is a letter that identifies the SCSI disk

and n is the partition number.

For example, /dev/sda is the first disk on the first SCSI

bus.

RAID disk

/dev/rd/cxdypz /dev/ida/cxdypz

Depending on the RAID controller,

RAID devices can have different device names. In the examples shown, x is a number that identifies the

controller, y is a number that

identifies the disk, and z is a

number that identifies the partition. For example, /dev/ida/c0d1 is

the second logical drive on the first

controller.

To

include devices in a disk group, you can specify either whole-drive device names

or partition device names.

Note:

Oracle recommends that you create a single whole-disk

partition on each disk.

Use either fdisk or parted to create a single

whole-disk partition on the disk devices.

Enter a command similar to the following to mark a disk as an Oracle ASM

disk:

# /usr/sbin/oracleasm createdisk DISK1 /dev/sdb1

In this example, DISK1 is the name you assign to the disk.

Note:

The disk names that you specify can contain uppercase

letters, numbers, and the underscore character. They must start with an

uppercase letter.

If you are using a multi-pathing disk driver with Oracle ASM, then make sure

that you specify the correct logical device name for the disk.

To make the disk available on the other nodes in the cluster, enter the

following command as root on each node:

# /usr/sbin/oracleasm scandisks

This command identifies shared disks attached to the node that are marked as

Oracle ASM disks.

3.3.1.4.3

Configuring Disk Devices to

Use ASM Library Driver on IBM: Linux on System z

If you formatted the DASD with the compatible disk layout, then enter a

command similar to the following to create a single whole-disk partition on the

device:

# /sbin/fdasd -a /dev/dasdxxxx

Enter a command similar to the following to mark a disk as an ASM disk:

# /etc/init.d/oracleasm createdisk DISK1 /dev/dasdxxxx

In this example, DISK1 is a name that you want to assign to the

disk.

Note:

The disk names that you specify can contain uppercase

letters, numbers, and the underscore character. They must start with an

uppercase letter.

If you are using a multi-pathing disk driver with ASM, then make sure that

you specify the correct logical device name for the disk.

To make the disk available on the other cluster nodes, enter the following

command as root on each node:

# /etc/init.d/oracleasm scandisks

This command identifies shared disks attached to the node that are marked as

ASM disks.

3.3.1.4.4

Administering the Oracle ASM

Library Driver and Disks

To administer the Oracle Automatic Storage Management library driver (ASMLIB)

and disks, use the oracleasm initialization script with different

options, as described in

Table 3-7

.

Table 3-7 ORACLEASM Script Options

Option

Description

configure

Use the configure option to reconfigure the Oracle Automatic

Storage Management library driver, if necessary:

# /usr/sbin/oracleasm configure -i

To see command options, enter oracleasm configure without the -i flag.

enable

disable

Use the disable and enable options to change the

actions of the Oracle Automatic Storage Management library driver when the

system starts. The enable option causes the Oracle Automatic

Storage Management library driver to load when the system starts:

# /usr/sbin/oracleasm enable

start

stop

restart

Use the start, stop, and restart options to load or unload the Oracle Automatic Storage Management library driver

without restarting the system:

# /usr/sbin/oracleasm restart

createdisk

Use the createdisk option to mark a disk device for use with the

Oracle Automatic Storage Management library driver and give it a name:

# /usr/sbin/oracleasm createdisk DISKNAME devicename

deletedisk

Use the deletedisk option to unmark a named disk device:

# /usr/sbin/oracleasm deletedisk DISKNAME

Caution:

Do not use this command to unmark disks that

are being used by an Oracle Automatic Storage Management disk group. You must

delete the disk from the Oracle Automatic Storage Management disk group before

you unmark it.

querydisk

Use the querydisk option to determine if a disk device or disk

name is being used by the Oracle Automatic Storage Management library

driver:

# /usr/sbin/oracleasm querydisk {DISKNAME | devicename}

listdisks

Use the listdisks option to list the disk names of marked Oracle

Automatic Storage Management library driver disks:

# /usr/sbin/oracleasm listdisks

scandisks

Use the scandisks option to enable cluster nodes to identify

which shared disks have been marked as Oracle Automatic Storage Management

library driver disks on another node:

# /usr/sbin/oracleasm scandisks

3.3.1.5

Configuring ASMLIB for

Multipath Disks

Additional configuration is required to use the Oracle Automatic Storage

Management library Driver (ASMLIB) with third party vendor multipath disks.

See Also:

My Oracle Support site for updates to supported

storage options:

https://support.oracle.com

3.3.1.5.1

About Using Oracle ASM with

Multipath Disks

Oracle ASM requires that each disk is uniquely identified. If the same disk

appears under multiple paths, then it causes errors. In a multipath disk

configuration, the same disk can appear three times:

The initial path to the disk

The second path to the disk

The multipath disk access point.

For example: If you have one local disk, /dev/sda, and one disk

attached with external storage, then your server shows two connections, or

paths, to that external storage. The Linux SCSI driver shows both paths. They

appear as /dev/sdb and /dev/sdc. The system may access

either /dev/sdb or /dev/sdc, but the access is to the

same disk.

If you enable multipathing, then you have a multipath disk (for example, /dev/multipatha), which can access both /dev/sdb and /dev sdc; any I/O to multipatha can use either the sdb or sdc path. If a system is using the /dev/sdb path, and that cable is unplugged, then the system shows

an error. But the multipath disk will switch from the /dev/sdb path

to the /dev/sdc path.

Most system software is unaware of multipath configurations. They can use any

paths (sdb, sdc or multipatha). ASMLIB

also is unaware of multipath configurations.

By default, ASMLIB recognizes the first disk path that Linux reports to it,

but because it imprints an identity on that disk, it recognizes that disk only

under one path. Depending on your storage driver, it may recognize the multipath

disk, or it may recognize one of the single disk paths.

Instead of relying on the default, you should configure Oracle ASM to

recognize the multipath disk.

3.3.1.5.2

Disk Scan Ordering

The

ASMLIB configuration file is located

in the path /etc/sysconfig/oracleasm. It contains all the startup

configuration you specified with the command /etc/init.d/oracleasm

configure. That command cannot configure scan ordering.

The configuration file contains many configuration variables. The ORACLEASM_SCANORDER variable specifies disks to be scanned first.

The ORACLEASM_SCANEXCLUDE variable specifies the disks that are to

be ignored.

Configure values for ORACLEASM_SCANORDER using space-delimited

prefix strings. A

prefix string

is the common string

associated with a type of disk. For example, if you use the prefix string sd, then this string matches all SCSI devices, including /dev/sda, /dev/sdb, /dev/sdc and so on.

Note that these are not globs. They do not use wild cards. They are simple

prefixes. Also note that the path is not a part of the prefix. For example, the /dev/ path is not part of the prefix for SCSI disks that are in the

path /dev/sd*.

For Oracle Linux and Red Hat Enterprise Linux version 5, when scanning, the

kernel sees the devices as /dev/mapper/XXX entries. By default, the 2.6 kernel

device file naming scheme udev creates the /dev/mapper/XXX names for human readability. Any configuration using ORACLEASM_SCANORDER should use the /dev/mapper/XXX entries.

3.3.1.5.3

Configuring Disk Scan

Ordering to Select Multipath Disks

To configure ASMLIB to select multipath disks first, complete the following

procedure:

Using a text editor, open the ASMLIB configuration file /etc/sysconfig/oracleasm.

Edit the ORACLEASM_SCANORDER variable to provide the prefix path of the

multipath disks. For example, if the multipath disks use the prefix multipath (/dev/mapper/multipatha, /dev/mapper/multipathb and so on), and the multipath disks mount

SCSI disks, then provide a prefix path similar to the following:

ORACLEASM_SCANORDER="multipath sd"

Save the file.

When you have completed this procedure, then when ASMLIB scans disks, it

first scans all disks with the prefix string multipath, and labels these disks

as Oracle ASM disks using the /dev/mapper/multipathX value. It then scans all disks with the

prefix string sd. However, because ASMLIB recognizes that these

disks have already been labeled with the /dev/mapper/multipath string values, it ignores these disks. After scanning for the prefix strings multipath and sd, Oracle ASM then scans for any other

disks that do not match the scan order.

In the example in step 2, the key word multipath is actually the alias for

multipath devices configured in /etc/multipath.conf under the multipaths section. For example:

multipaths {

multipath {

wwid                    3600508b4000156d700012000000b0000

alias                   multipath

...

}

multipath {

...

alias                   mympath

...

}

...

}

The default device name is in the format /dev/mapper/mpath* (or a similar

path).

3.3.1.5.4

Configuring Disk Order Scan

to Exclude Single Path Disks

To configure ASMLIB to exclude particular single path disks, complete the

following procedure:

Using a text editor, open the ASMLIB configuration file /etc/sysconfig/oracleasm.

Edit the ORACLEASM_SCANEXCLUDE variable to provide the prefix

path of the single path disks. For example, if you want to exclude the single

path disks /dev sdb and /dev/sdc, then provide a

prefix path similar to the following:

ORACLEASM_SCANEXCLUDE="sdb sdc"

Save the file.

When you have completed this procedure, then when ASMLIB scans disks, it

scans all disks except for the disks with the sdb and sdc prefixes, so that it ignores /dev/sdb and /dev/sdc. It does not ignore other SCSI disks, nor multipath disks.

If you have a multipath disk (for example, /dev/multipatha), which

accesses both /dev/sdb and /dev sdc, but you have

configured ASMLIB to ignore sdb and sdc, then ASMLIB

ignores these disks and instead marks only the multipath disk as an Oracle ASM

disk.

在采用

asmlib

在采用

asmlib

驱动时，此时，通过

v$asm_

disk

可以通过如下的几种方法实现：

1

方法：

[root@rac1 ~]# dd if=/dev/sdb13 bs=1 count=45 |hexdump -c |more

45+0 records in

45+0 records out

45 bytes (45 B) copied, 9.4e-05 seconds, 479 kB/s

0000000 001 202 001 001  \0  \0  \0  \0  \0  \0  \0 200 253 243 245 371

0000010  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0

0000020   O   R   C   L   D   I   S   K   V   O   L   1   2

000002d

为

VOL1

2

、通过

major号确定：

[root@rac1 ~]# ls -l /dev/oracleasm/disks/VOL12

brw-rw---- 1 oracle oinstall 8, 29 May 15 22:02 /dev/oracleasm/disks/VOL12

[root@rac1 ~]# ls -l /dev/sd* |grep "8, 29"

brw-r----- 1 root disk 8, 29 May 15 22:02 /dev/sdb13

[grid@node2 ~]$ cd /dev/oracleasm/disks/

[grid@node2 disks]$ ll

total 0

brw-rw---- 1 grid oinstall 8, 33 Mar 10 12:04 ARCHDISK

brw-rw---- 1 grid oinstall 8, 49 Mar 10 12:04 DATADISK

brw-rw---- 1 grid oinstall 8, 65 Mar 10 12:04 OVDISK

[grid@node2 disks]$ ls -l /dev/sd* |grep "8, 33"

brw-rw---- 1 grid oinstall 8, 33 Mar 10 12:04 /dev/sdc1

[grid@node2 disks]$ ls -l /dev/sd* |grep "8, 49"

brw-r----- 1 root disk     8, 49 Mar 10 12:04 /dev/sdd1

[grid@node2 disks]$ ls -l /dev/sd* |grep "8, 65"

brw-rw---- 1 grid oinstall 8, 65 Mar 10 12:04 /dev/sde1

[grid@node2 disks]$

由于一个测试的需要，笔者需要在redhat linxu 6.5上安装ASMLIB。

根据ORACLE的要求，在redhat上安装ASMLIB，需要安装如下三个包：

oracleasm-support-version.arch.rpm

oracleasm-kernel-version.arch.rpm

oracleasmlib-version.arch.rpm

可是，ORACLE为了推广她自己的ORACLE LINUX操作系统，上面三个rpm包只在redhat linux 5及以前版本提供，在redhat linux 6上，不再提供oracleasm-kernel-version.arch.rpm这个包了，但是在ORACLE linux上，这个包是集成在UEK中的，这直接导致在redhat linux 6上无法安装oracleasm-support-version.arch.rpm和oracleasmlib-version.arch.rpm这两个rpm包。ORACLE真是奸商啊。

但是redhat也不能坐以待毙呀，她就开发了kmod-oracleasm-XXX.el6.x86_64.rpm这个rpm包，在redhat linux 6上需要先安装它，才能安装得了oracle提供的oracleasmlib-version.arch.rpm包，kmod-oracleasm-XXX.el6.x86_64.rpm这个包在redhat的官网上的经授权的用户可以下载得到。

下面是笔者的redhat 6.5上为了使用asmlib而安装的三个包：

(1)kmod-oracleasm-2.0.6.rh1-3.el6.x86_64.rpm

--注意redhat 6.5它的内核版本号是2.6.32,，所以装的kmod-oracleasm的版本号是2.0.6.rh1-3，如果内核版本低于2.6.32，则装的kmod-oracleasm的版本号应该是2.0.6.rh1-2或更低版本

(2)oracleasm-support-2.1.8-1.el6.x86_64.rpm

(3)oracleasmlib-2.0.4-1.el6.x86_64.rpm