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标题：linux 7(redhat,oracle linux,centos)中使用udev

作者：惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]

慢慢的linux 7的使用人越来越多了,但是linux 7相对于5和6的版本,变动确实比较大,本文主要描写在linux 7中如何实现udev,实现设备持久化,权限和所属组的修改
linux版本

Oracle Linux Server release 7.1
[root@www.xifenfei.com ~]# uname -a
Linux www.xifenfei.com 3.10.0-229.el7.x86_64 #1 SMP Fri Mar 6 04:05:24 PST 2015 x86_64 x86_64 x86_64 GNU/Linux

VMware Workstation中显示uuid需要在vmx文件中增加

disk.enableUUID = "TRUE"

查看磁盘分区

[root@www.xifenfei.com ~]# fdisk -l

Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0xf60fe217

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048     2099199     1048576   83  Linux

Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000bce7c

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048     4204543     2101248   8e  Linux LVM
/dev/sda2   *     4204544    79702015    37748736   83  Linux

Disk /dev/sdc: 32.2 GB, 32212254720 bytes, 62914560 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/ol-swap: 2147 MB, 2147483648 bytes, 4194304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

查看磁盘uuid

[root@www.xifenfei.com ~]# /usr/lib/udev/scsi_id -g -u /dev/sdb1
36000c29e91831cedbe69afe6cc08daf7
[root@www.xifenfei.com ~]# /usr/lib/udev/scsi_id -g -u /dev/sdc
36000c292495e9d9de6f21640cc7b53b9

udev绑定

[root@www.xifenfei.com ~]# more /etc/udev/rules.d/99-my-asmdevices.rules 
KERNEL=="sd*[!0-9]", ENV{DEVTYPE}=="disk", SUBSYSTEM=="block", PROGRAM=="/usr/lib/udev/scsi_id -g -u -d $devnode",
 RESULT=="36000c292495e9d9de6f21640cc7b53b9", RUN+="/bin/sh -c 'mknod /dev/xifenfei-sdc b $major $minor; 
chown oracle:dba /dev/xifenfei-sdc; chmod 0660 /dev/xifenfei-sdc'"

KERNEL=="sd?1", SUBSYSTEM=="block", PROGRAM=="/lib/udev/scsi_id -g -u -d /dev/$parent", 
RESULT=="36000c29e91831cedbe69afe6cc08daf7", SYMLINK+="xifenfei-sdb1", OWNER="oracle", GROUP="dba", MODE="0660"

绑定结果

[root@www.xifenfei.com ~]# ls -l /dev/xifenfei-*
lrwxrwxrwx. 1 root   root     4 Aug  7 22:49 /dev/xifenfei-sdb1 -> sdb1
brw-rw----. 1 oracle dba  8, 32 Aug  7 22:36 /dev/xifenfei-sdc
[root@www.xifenfei.com ~]# ls -l /dev/sdb1
brw-rw----. 1 oracle dba 8, 17 Aug  7 22:49 /dev/sdb1

udev只修改磁盘权限

[root@www.xifenfei.com ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Command (m for help): n
Partition type:
   p   primary (1 primary, 0 extended, 3 free)
   e   extended
Select (default p): p
Partition number (2-4, default 2): 
First sector (2099200-41943039, default 2099200): 
Using default value 2099200
Last sector, +sectors or +size{K,M,G} (2099200-41943039, default 41943039): +1G
Partition 2 of type Linux and of size 1 GiB is set

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

Calling ioctl() to re-read partition table.
Syncing disks.
[root@www.xifenfei.com ~]# more /etc/udev/rules.d/99-my-asmdevices.rules 
KERNEL=="sd?2", SUBSYSTEM=="block", PROGRAM=="/lib/udev/scsi_id -g -u -d /dev/$parent",
 RESULT=="36000c29e91831cedbe69afe6cc08daf7",  OWNER="oracle", GROUP="dba", MODE="0660"
[root@www.xifenfei.com ~]# /sbin/udevadm trigger --type=devices --action=change
[root@www.xifenfei.com ~]# ls -l /dev/sdb2
brw-rw----. 1 oracle dba 8, 18 Aug  7 23:14 /dev/sdb2

这里可以发现在linux 7中使用了两种方法绑定udev,一种是真实生成udev设备,另外一种是通过软连接实现.感谢lunar(Lunar的oracle实验室)在linux 7学习中的帮助