linux 使用裸设备创建表空间

环境
系统环境
[root@node1 ~]# uname -a
linux node1 2.6.18-194.el5 #1 SMP Tue Mar 16 21:52:43 EDT 2010 i686 i686 i386 GNU/Linux   
[root@node1 ~]# more /etc/redhat-release 
Red Hat Enterprise Linux Server release 5.5 (Tikanga)
[root@node1 ~]# 
oracle环境
sql> select * from v$version;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production

查看磁盘
[root@node1 ~]# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        2610    20860402+  8e  Linux LVM

Disk /dev/sdb: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        2610    20964793+  83  Linux

Disk /dev/sdc: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdc doesn't contain a valid partition table
给/dev/sdc 划分一个1g的分区  用作裸设备
[root@node1 ~]# fdisk /dev/sdc
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.

The number of cylinders for this disk is set to 1044.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

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 or +size or +sizeM or +sizeK (1-1044, default 1044): +1024M

Command (m for help): p
Disk /dev/sdc: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1         125     1004031   83  Linux

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

修改/etc/udev/rules.d/60-raw.rules 文件    
[root@node1 ~]# vi /etc/udev/rules.d/60-raw.rules 
# Enter raw device bindings here.
#
# An example would be:
#   ACTION=="add", KERNEL=="sda", RUN+="/bin/raw /dev/raw/raw1 %N"
# to bind /dev/raw/raw1 to /dev/sda, or
#   ACTION=="add", ENV{MAJOR}=="8", ENV{MINOR}=="1", RUN+="/bin/raw /dev/raw/raw2 %M %m"
# to bind /dev/raw/raw2 to the device with major 8, minor 1.

ACTION=="add", KERNEL=="sdc1", RUN+="/bin/raw /dev/raw/raw1 %N"
ACTION=="add", KERNEL=="sdc2", RUN+="/bin/raw /dev/raw/raw2 %N"

ACTION=="add", ENV{MAJOR}=="3", ENV{MINOR}=="1", RUN+="/bin/raw /dev/raw/raw1 %M %m"
ACTION=="add", ENV{MAJOR}=="7", ENV{MINOR}=="1", RUN+="/bin/raw /dev/raw/raw2 %M %m"
~

启动裸设备
[root@node1 ~]# start_udev
Starting udev:                                             [  OK  ]
[root@node1 ~]# 
修改裸设备的主设备号和复设备号
[root@node1 ~]# raw -qa
/dev/raw/raw1:  bound to major 8, minor 33
[root@node1 ~]# raw /dev/raw/raw1 1 1
/dev/raw/raw1:  bound to major 1, minor 1
[root@node1 ~]# raw -qa
/dev/raw/raw1:  bound to major 1, minor 1
删除裸设备，当然还必须修改/etc/udev/rules.d/60-raw.rules 文件
[root@node1 ~]# raw /dev/raw/raw1 0 0
/dev/raw/raw1:  bound to major 0, minor 0
[root@node1 ~]# raw -qa
[root@node1 ~]# raw /dev/raw/raw1 1 1
/dev/raw/raw1:  bound to major 1, minor 1
[root@node1 ~]# raw -qa
/dev/raw/raw1:  bound to major 1, minor 1

修改裸设备的权限                        
[root@node1 ~]# raw -qa
/dev/raw/raw1:  bound to major 8, minor 33
/dev/raw/raw2:  bound to major 8, minor 34
[root@node1 ~]# cd /dev/raw
[root@node1 raw]# ls -l
total 0
crw------- 1 root root 162, 1 Apr  7 18:03 raw1
crw------- 1 root root 162, 2 Apr  7 18:03 raw2
[root@node1 raw]# chown oracle:oinstall raw1
[root@node1 raw]# chown oracle:oinstall raw2
[root@node1 raw]# chmod 775 raw1 raw2
[root@node1 raw]# ls -l
total 0
crwxrwxr-x 1 oracle oinstall 162, 1 Apr  7 18:03 raw1
crwxrwxr-x 1 oracle oinstall 162, 2 Apr  7 18:03 raw2
查看裸设备的可用空间                               
[root@node1 raw]# blockdev --getsize /dev/raw/raw1
2008062
[root@node1 raw]# blockdev --getsize /dev/raw/raw2
2008125

2008125*512/1024/1024=980M

在oracle中添加裸设备为数据文件的表空间
SQL> create tablespace tbs_raw datafile'/dev/raw/raw1' size 950m;
Tablespace created.