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标题：使用losetup实现linux普通文件做asm disk
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上一篇文章《使用_asm_allow_only_raw_disks实现普通文件做asm disk》中已经介绍使用_asm_allow_only_raw_disks参数使得oracle asm可以使用文件作为asm disk,这篇文章介绍在linux中还可以通过losetup来实现文件系统模拟磁盘实现使用文件系统做asm disk的效果
通过dd构造文件
[oracle@xifenfei ~]$ mkdir /u01/oracle/oradata/asmdisk [oracle@xifenfei ~]$ dd if=/dev/zero of=/u01/oracle/oradata/asmdisk/xifenfei01.dd bs=10240k count=100 100+0 records in 100+0 records out 1048576000 bytes (1.0 GB) copied, 21.9158 seconds, 47.8 MB/s [oracle@xifenfei ~]$ dd if=/dev/zero of=/u01/oracle/oradata/asmdisk/xifenfei02.dd bs=10240k count=100 100+0 records in 100+0 records out 1048576000 bytes (1.0 GB) copied, 22.392 seconds, 46.8 MB/s [oracle@xifenfei ~]$ ls -lh /u01/oracle/oradata/asmdisk/ total 3.0G -rw-r--r-- 1 oracle oinstall 1000M Feb 27 22:58 xifenfei01.dd -rw-r--r-- 1 oracle oinstall 1000M Feb 27 23:00 xifenfei02.dd
使用losetup模拟磁盘
[root@xifenfei asmdisk]# ls -l /dev/lo log loop0 loop1 loop2 loop3 loop4 loop5 loop6 loop7 [root@xifenfei asmdisk]# losetup /dev/loop1 xifenfei01.dd [root@xifenfei asmdisk]# losetup /dev/loop2 xifenfei02.dd
使用raw实现磁盘转换为裸设备
[root@xifenfei asmdisk]# raw /dev/raw/raw10 /dev/loop1 /dev/raw/raw10: bound to major 7, minor 1 [root@xifenfei asmdisk]# raw /dev/raw/raw11 /dev/loop2 /dev/raw/raw11: bound to major 7, minor 2 [root@xifenfei asmdisk]# ls -l /dev/raw/raw1[0-1] crw------- 1 root root 162, 10 Feb 27 23:16 /dev/raw/raw10 crw------- 1 root root 162, 11 Feb 27 23:16 /dev/raw/raw11 [root@xifenfei asmdisk]# chown oracle.dba /dev/raw/raw1[0-1] [root@xifenfei asmdisk]# ls -l /dev/raw/raw1[0-1] crw------- 1 oracle dba 162, 10 Feb 27 23:16 /dev/raw/raw10 crw------- 1 oracle dba 162, 11 Feb 27 23:16 /dev/raw/raw11
创建磁盘组
[oracle@xifenfei ~]$ export ORACLE_SID=+ASM
[oracle@xifenfei ~]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.4.0 - Production on Thu Feb 27 23:19:28 2014
Copyright (c) 1982, 2007, Oracle. All Rights Reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> create diskgroup xff external redundancy disk '/dev/raw/raw10','/dev/raw/raw11';
Diskgroup created.
SQL> select group_number,name from v$asm_diskgroup;
GROUP_NUMBER NAME
------------ ------------------------------------------------------------
1 DATA
2 XFF
SQL> select path,TOTAL_MB from v$asm_disk where group_number=2;
PATH TOTAL_MB
-------------------- ----------
/dev/raw/raw11 1000
/dev/raw/raw10 1000
通过kfed验证asm disk是数据文件
[oracle@xifenfei tmp]$ kfed read /dev/raw/raw10|grep XFF kfdhdb.dskname: XFF_0000 ; 0x028: length=8 kfdhdb.grpname: XFF ; 0x048: length=3 kfdhdb.fgname: XFF_0000 ; 0x068: length=8 [oracle@xifenfei tmp]$ kfed read /dev/raw/raw11|grep XFF kfdhdb.dskname: XFF_0001 ; 0x028: length=8 kfdhdb.grpname: XFF ; 0x048: length=3 kfdhdb.fgname: XFF_0001 ; 0x068: length=8 [oracle@xifenfei tmp]$ kfed read /u01/oracle/oradata/asmdisk/xifenfei01.dd |grep XFF kfdhdb.dskname: XFF_0000 ; 0x028: length=8 kfdhdb.grpname: XFF ; 0x048: length=3 kfdhdb.fgname: XFF_0000 ; 0x068: length=8 [oracle@xifenfei tmp]$ kfed read /u01/oracle/oradata/asmdisk/xifenfei02.dd |grep XFF kfdhdb.dskname: XFF_0001 ; 0x028: length=8 kfdhdb.grpname: XFF ; 0x048: length=3 kfdhdb.fgname: XFF_0001 ; 0x068: length=8
通过kfed命令,确定asm本质是用了dd出来的数据文件做asm disk.