solaris 系统asm磁盘注意事项：

参考手册：
ASM Does Not Discover Disk on Solaris (文档 ID 368840.1)

磁盘注意事项：

1,solaris asm分区从第三个柱面开始(否则在重启系统之后asm磁盘头信息会丢失,由于vtoc原因导致。)

2,禁止使用s2分区（Partition # 2 is a standard partition and it SHOULD NOT be changed as it reflects the total capacity of the disk. ）

解决方法：

**Modifying the partitions, starting few cylinders ahead (1 or 2 to avoid wasting space), will help ASM to discover the disk.

The following output displays the disk originally presented, but now with partition 0 starting at cylinder 3:
**

Part Tag Flag Cylinders Size Blocks
0 unassigned wm 3 - 51197 100.00GB (51198/0/0) 209707008
1 unassigned wm 0 0 (0/0/0) 0
2 backup wu 0 - 51197 100.00GB (51198/0/0) 209707008
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0

The disk configured was c3t42d10 and the partition selected was 0 (S0), which is reflected as /dev/rdsk/c3t42d10S0.

Having a valid value for parameter asm_disktring that resolves /dev/rdsk/c3t42d10S0 and running a query on v$asm_disk will now discover the disk and it will be available for ASM.

3.3.1.4 Configuring Disk Devices for Oracle ASM
You can configure raw partitions for use as Oracle ASM disk groups. To use ASM with raw partitions, you must create sufficient partitions for your data files, and then bind the partitions to raw devices. Make a list of the raw device names you create for the data files, and have the list available during database installation.

Use the following procedure to configure disks:

If necessary, install the disks that you intend to use for the disk group and restart the system.

Identify or create the disk slices (partitions) that you want to include in the Oracle ASM disk group:

To ensure that the disks are available, enter the following command:

# /usr/sbin/format
The output from this command is similar to the following:

AVAILABLE DISK SELECTIONS:
       0. c0t0d0 <ST34321A cyl 8892 alt 2 hd 15 sec 63>
          /pci@1f,0/pci@1,1/ide@3/dad@0,0
       1. c1t5d0 <SUN9.0G cyl 4924 alt 2 hd 27 sec 133>
          /pci@1f,0/pci@1/scsi@1/sd@5,0
This command displays information about each disk attached to the system, including the device name (cxtydz).

Enter the number corresponding to the disk that you want to use.

Use the fdisk command to create an Oracle Solaris partition on the disk if one does not already exist.

Oracle Solaris fdisk partitions must start at cylinder 1, not cylinder 0. If you create an fdisk partition, then you must label the disk before continuing.

Enter the partition command, followed by the print command to display the partition table for the disk that you want to use.

If necessary, create a single whole-disk slice, starting at cylinder 1.

Note:

To prevent Oracle ASM from overwriting the partition table, you cannot use slices that start at cylinder 0 (for example, slice 2).
Make a note of the number of the slice that you want to use.

If you modified a partition table or created a new one, then enter the label command to write the partition table and label to the disk.

Enter q to return to the format menu.

If you have finished creating slices, then enter q to quit from the format utility. Otherwise, enter the disk command to select a new disk and repeat steps b to g to create or identify the slices on that disks.

If you plan to use existing slices, then enter the following command to verify that they are not mounted as file systems:

# df -h
This command displays information about the slices on disk devices that are mounted as file systems. The device name for a slice includes the disk device name followed by the slice number. For example: cxtydzsn, where sn is the slice number.

Enter commands similar to the following on every node to change the owner, group, and permissions on the character raw device file for each disk slice that you want to add to a disk group, where grid is the Oracle Grid Infrastructure installation owner, and asmadmin is the OSASM group:

# chown grid:asmadmin /dev/rdsk/cxtydzs6
# chmod 660 /dev/rdsk/cxtydzs6
In this example, the device name specifies slice 6.


https://docs.oracle.com/cd/E11882_01/install.112/e47805/storage.htm#CWSOL272