從安裝Oracle Database的角度來看，Oracle Linux要比Red Hat Linux更加適合，況且即使是Red Hat Linux 6，ASMLib也不是唯一的選擇，但出於歷史原因，我們通過這篇文章討論一下在Red Hat Linux Server 6上能否使用ASMLib？
下面是Oracle對在Red Hat Linux 6上使用ASMLib的說明：
Oracle ASMLib Downloads for Red Hat Enterprise Linux Server 6
Note: All ASMLib installations require that the 'kmod-oracleasm','oracleasmlib' and 'oracleasm-support' packages be installed on the system. The 'oracleasmlib' and 'oracleasm-support' packages are available for download at the locations listed below.
The kernel driver package 'kmod-oracleasm' is available directly from Red Hat, and can be installed from the "RHEL Server Supplementary (v. 6 64-bit x86_64)" channel on Red Hat Network (RHN). Use the ASMLib kernel driver that corresponds to the version of the Red Hat Enterprise Linux kernel you're running.
To identify which version of the ASMLib kernel driver you need, view the description field of the 'kmod-oracleasm' package in the "RHEL Server Supplementary (v. 6 64-bit x86_64)" channel on RHN.
使用ASMLib需要3個包：kmod-oracleasm oracleasmlib oracleasm-support，後兩個包都可以直接在網站上下載到，關鍵是第一個ASMLib內核驅動包需要到RHN上更新，且應該匹配操作系統的內核版本。
以上文字來源於：http://www.oracle.com/technetwork/server-storage/linux/asmlib/rhel6-1940776.html
下面是Oracle對在Oracle Linux 6上使用ASMLib的說明：
Oracle ASMLib Downloads for Oracle Linux 6
Note: All ASMLib installations require the oracleasmlib and oracleasm-support packages appropriate for their machine.
The oracleasm-support package can be downloaded from the Unbreakable Linux Network(ULN) if you have an active support subscription, or from http://public-yum.oracle.com if you do not.
The oracleasm kernel driver is built into the Unbreakable Enterprise Kernel for Oracle Linux 6 and does not need to be installed manually.
The oracleasm kernel driver for the 64-bit (x86_64) Red Hat Compatible Kernel for Oracle Linux 6 can be installed manually from ULN or http://public-yum.oracle.com using the yum tool:
# yum install kmod-oracleasm
This kernel driver is not version-specific and does not need to be upgraded when the kernel is upgraded.
如果使用的是Oracle Linux的uek內核，oracleasm已經被編譯到了內核中，如果使用的是和Red Hat兼容的內核，那麼需要手動安裝kmod-oracleasm包。
以上文字來源於：
http://www.oracle.com/technetwork/server-storage/linux/asmlib/ol6-1709075.html
[root@localhost ~]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# ls
rhel-source.repo
[root@localhost yum.repos.d]# wget http://public-yum.oracle.com/public-yum-ol6.repo
--2014-03-25 22:43:05-- http://public-yum.oracle.com/public-yum-ol6.repo
Resolving public-yum.oracle.com... 2.16.54.48, 2.16.54.96
Connecting to public-yum.oracle.com|2.16.54.48|:80... failed: Connection reset by peer.
Connecting to public-yum.oracle.com|2.16.54.96|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 4233 (4.1K) [text/plain]
Saving to: “public-yum-ol6.repo”
100%[===================================================================================================>] 4,233 --.-K/s in 0s
2014-03-25 22:43:07 (190 MB/s) - “public-yum-ol6.repo” saved [4233/4233]
[root@localhost yum.repos.d]# wget http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6 -O /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
--2014-03-25 23:06:00-- http://public-yum.oracle.com/RPM-GPG-KEY-oracle-ol6
Resolving public-yum.oracle.com... 46.33.75.121, 46.33.75.138
Connecting to public-yum.oracle.com|46.33.75.121|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1011 [text/plain]
Saving to: “/etc/pki/rpm-gpg/RPM-GPG-KEY-oracle”
100%[===================================================================================================>] 1,011 --.-K/s in 0s
2014-03-25 23:06:01 (27.6 MB/s) - “/etc/pki/rpm-gpg/RPM-GPG-KEY-oracle” saved [1011/1011]
[root@localhost yum.repos.d]# yum install kmod-oracleasm
Loaded plugins: product-id, refresh-packagekit, security, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package kmod-oracleasm.x86_64 0:2.0.6.rh1-2.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=============================================================================================================================================
Package Arch Version Repository Size
=============================================================================================================================================
Installing:
kmod-oracleasm x86_64 2.0.6.rh1-2.el6 ol6_latest 34 k
Transaction Summary
=============================================================================================================================================
Install 1 Package(s)
Total size: 34 k
Installed size: 115 k
Is this ok [y/N]: y
Downloading Packages:
warning: rpmts_HdrFromFdno: Header V3 RSA/SHA256 Signature, key ID ec551f03: NOKEY
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
Importing GPG key 0xEC551F03:
Userid: "Oracle OSS group (Open Source Software group) "@oss.oracle.com>
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
Is this ok [y/N]: y
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : kmod-oracleasm-2.0.6.rh1-2.el6.x86_64 1/1
mylocalnet/productid | 1.7 kB 00:00 ...
Verifying : kmod-oracleasm-2.0.6.rh1-2.el6.x86_64 1/1
Installed:
kmod-oracleasm.x86_64 0:2.0.6.rh1-2.el6
Complete!
------------------------------------------------------------------------
oracleasmlib-2.0.4-1.el6.x86_64.rpm
oracleasm-support-2.1.8-1.el6.x86_64.rpm
這兩個包可以通過ORACLE官方網站進行下載 http://www.oracle.com/technetwork/server-storage/linux/asmlib/rhel6-1940776.html
[root@localhost opt]# rpm -ivh oracleasmlib-2.0.4-1.el6.x86_64.rpm oracleasm-support-2.1.8-1.el6.x86_64.rpm
Preparing... ########################################### [100%]
1:oracleasm-support ########################################### [ 50%]
2:oracleasmlib ########################################### [100%]
至此在Red Hat Linux Server 6.4 x86_64bit上成功安裝了kmod-oracleasm oracleasm-support oracleasmlib 3個包。
[root@localhost ~]# /etc/init.d/oracleasm configure
Configuring the Oracle ASM library driver.
This will configure the on-boot properties of the Oracle ASM library
driver. The following questions will determine whether the driver is
loaded on boot and what permissions it will have. The current values
will be shown in brackets ('[]'). Hitting <ENTER> without typing an
answer will keep that current value. Ctrl-C will abort.
Default user to own the driver interface []: grid
Default group to own the driver interface []: asmadmin
Start Oracle ASM library driver on boot (y/n) [n]: y
Scan for Oracle ASM disks on boot (y/n) [y]: y
Writing Oracle ASM library driver configuration: done
Initializing the Oracle ASMLib driver: [FAILED]
目前知道可能導致這個錯誤的原因有兩個：
1.oracle asmlib內核和linux系統內核不符，修正方法，到oracle網站下載內核版本符合的asmlib，從新安裝。
[root@rac01 etc]# uname -r
2.6.32-220.el6.x86_64
[root@rac01 oracle]# rpm -qa|grep oracleasm
oracleasm-support-2.1.8-1.el6.x86_64
kmod-oracleasm-2.0.8-6.el6_7.x86_64
oracleasmlib-2.0.4-1.el6.x86_64
發現在使用yum安裝kmod-oracleasm時同時Updateb了一個新的kernel,原有內核爲2.6.32-220.el6.x86_64、新內核爲2.6.32-573.12.1.el6.x86_64。
[root@localhost ~]# cat /boot/grub/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/sda2
# initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-573.12.1.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-573.12.1.el6.x86_64 ro root=UUID=259c88b6-618d-4050-bb4a-a92f747e2f29 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM
initrd /initramfs-2.6.32-573.12.1.el6.x86_64.img
title CentOS (2.6.32-220.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-220.el6.x86_64 ro root=UUID=259c88b6-618d-4050-bb4a-a92f747e2f29 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM
initrd /initramfs-2.6.32-220.el6.x86_64.img
-------------------------------------------------------------
重啓系統加載新的內核。
2.linux的selinux沒有設置爲disable
# vi /etc/selinux/config (把SELINUX置爲disabled)
SELINUX=disabled
[root@localhost ~]# /etc/init.d/oracleasm configure
Configuring the Oracle ASM library driver.
This will configure the on-boot properties of the Oracle ASM library
driver. The following questions will determine whether the driver is
loaded on boot and what permissions it will have. The current values
will be shown in brackets ('[]'). Hitting without typing an
answer will keep that current value. Ctrl-C will abort.
Default user to own the driver interface []: grid
Default group to own the driver interface []: asmadmin
Start Oracle ASM library driver on boot (y/n) [n]: y
Scan for Oracle ASM disks on boot (y/n) [y]:
Writing Oracle ASM library driver configuration: done
Initializing the Oracle ASMLib driver: [ OK ]
Scanning the system for Oracle ASMLib disks: [ OK ]
[root@localhost ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000f1993
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 679 5242880 82 Linux swap / Solaris
Partition 2 does not end on cylinder boundary.
/dev/sda3 679 6528 46980096 83 Linux
Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
[root@localhost ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x15fd0887.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-1044, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-1044, default 1044):
Using default value 1044
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@cafis ~]# /etc/init.d/oracleasm createdisk VOL1 /dev/sdb1
Marking disk "VOL1" as an ASM disk: [ OK ]
查看硬盤設置與ASM disk對應關係
[root@localhost disks]# ls -lt
total 0
brw-rw---- 1 oracle oinstall 8, 17 Nov 30 23:02 VOL1
[root@cafis disks]# cd /dev/
[root@cafis dev]# ls -lt sd*
brw-rw---- 1 root disk 8, 17 Nov 30 23:04 sdb1
brw-rw---- 1 root disk 8, 16 Nov 30 23:04 sdb
brw-rw---- 1 root disk 8, 1 Nov 30 23:00 sda1
brw-rw---- 1 root disk 8, 2 Nov 30 23:00 sda2
brw-rw---- 1 root disk 8, 3 Nov 30 23:00 sda3
brw-rw---- 1 root disk 8, 5 Nov 30 23:00 sda5
brw-rw---- 1 root disk 8, 4 Nov 30 23:00 sda4
brw-rw---- 1 root disk 8, 0 Nov 30 23:00 sda
可以看到/dev/sdb1,/dev/oracleasm/disks/VOL1兩個設備的設備號8,17是相同的,說明它們是一一對應的關係.
通過oracleasm命令也可以查詢出這種對應關係.
[root@ocmdb1 dev]# oracleasm listdisks
VOL1
[root@ocmdb1 dev]# oracleasm querydisk VOL1
Disk "VOL1" is a valid ASM disk
[root@ocmdb1 dev]# oracleasm querydisk /dev/sdb1
Device "/dev/sdb1" is marked an ASM disk with the label "VOL1"
[root@ocmdb1 dev]# oracleasm querydisk -d VOL1
Disk "VOL1" is a valid ASM disk on device [8, 17]
[root@ocmdb1 dev]# oracleasm querydisk /dev/sda5
Device "/dev/sda5" is not marked as an ASM disk ##/dev/sda5不是asm盤
---------------------------------
自已做了一把，總結遇到的問題，以及查看網絡和自己排查後的一些方法，記錄並與大家分享。