linux磁盘重启乱序问题处理linux

最近到客户那去巡检时，客户提到一个问题，他们的rac在重启的时候，原来的sda一、sdb一、sdc1会对应变成sdd一、sde一、sdf1，因为他们使用的是盘符来绑定裸设备，因此启动后，常常要手动执行如下命令

[root@ractest1 ~]# raw /dev/raw/raw1 /dev/sda1

[root@ractest1 ~]# raw /dev/raw/raw2 /dev/sdb1

[root@ractest1 ~]# raw /dev/raw/raw3 /dev/sdc1

而且，比较奇怪的事，两边有时认得的盘彻底不同，一边是sda\b\c，另外一边是sdd\e\f，这样，使oracle rac的共享盘出现问题。oracle

在了解了他们的状况后，我基本上明白是什么缘由，这种盘序错乱，与linux对磁盘的扫描机制有关，因此咱们只能从另外一角度去规避这样的问题，使用id号去绑定，这样就没有问题。在告诉他后，他赞成咱们对他原来的绑定方式进行修改，具体操做以下：ui

[root@ractest1 ~]# fdisk -lspa

Disk /dev/sdd: 429.4 GB, 429496729600 bytes

255 heads, 63 sectors/track, 52216 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes.net

Device Boot      Start         End      Blocks   Id  System

/dev/sdd1               1       52216   419424988+  83  Linuxblog

Disk /dev/sde: 209 MB, 209715200 bytes

7 heads, 58 sectors/track, 1008 cylinders

Units = cylinders of 406 * 512 = 207872 bytesip

Device Boot      Start         End      Blocks   Id  System

/dev/sde1               1        1008      204595   83  Linuxci

Disk /dev/sdf: 209 MB, 209715200 bytes

7 heads, 58 sectors/track, 1008 cylinders

Units = cylinders of 406 * 512 = 207872 bytesget

Device Boot      Start         End      Blocks   Id  System

/dev/sdf1               1        1008      204595   83  Linuxinput

能够看到，刚重启的节点1是sdd/sde/sdf

另外一个节点的状况是：

[root@ractest2 ~]# fdisk -l

Disk /dev/sda: 429.4 GB, 429496729600 bytes

255 heads, 63 sectors/track, 52216 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sda1               1       52216   419424988+  83  Linux

Disk /dev/sdb: 209 MB, 209715200 bytes

7 heads, 58 sectors/track, 1008 cylinders

Units = cylinders of 406 * 512 = 207872 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sdb1               1        1008      204595   83  Linux

Disk /dev/sdc: 209 MB, 209715200 bytes

7 heads, 58 sectors/track, 1008 cylinders

Units = cylinders of 406 * 512 = 207872 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sdc1               1        1008      204595   83  Linux

分别在两台机子上执行以下命令：

[root@ractest2 ~] /usr/lib/udev/scsi_id -g -s /block/sda

360080e500017ff06000004054c47bd4a

[root@ractest2 ~] /usr/lib/udev/scsi_id -g -s /block/sdb

360080e500017fdd8000004c74c6344ef

[root@ractest2 ~] /usr/lib/udev/scsi_id -g -s /block/sdc

360080e500017ff060000044f4c63446e

[root@ractest1 ~] /usr/lib/udev/scsi_id -g -s /block/sdd

360080e500017ff06000004054c47bd4a

[root@ractest1 ~] /usr/lib/udev/scsi_id  -g -s /block/sde

360080e500017fdd8000004c74c6344ef

[root@ractest1 ~] /usr/lib/udev/scsi_id -g -s /block/sdf

360080e500017ff060000044f4c63446e

能过对比，能够看到sda与sdd，sdb与sde，sdc与sdf是对应用的，因此咱们启用udev，经过绑定id来规避这个问题！

[root@ractest1 ~]# cd /etc/udev/rules.d/

[root@ractest1 rules.d]# ls -a

.                    50-udev.rules     60-pcmcia.rules         61-uinput-wacom.rules  90-hal.rules

..                   51-hotplug.rules  60-raw.rules            85-pcscd_ccid.rules    95-pam-console.rules

05-udev-early.rules  60-libsane.rules  60-wacom.rules          90-alsa.rules          98-kexec.rules

40-multipath.rules   60-net.rules      61-uinput-stddev.rules  90-dm.rules            bluetooth.rules

[root@ractest1 rules.d]# vi 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=="sd*1", PROGRAM=="/sbin/scsi_id -g -u -s %p", RESULT=="360080e500017ff060000044f4c63446e", RUN+="/bin/raw /dev/raw/raw1 %N"

ACTION=="add", KERNEL=="sd*1", PROGRAM=="/sbin/scsi_id -g -u -s %p", RESULT=="360080e500017fdd8000004c74c6344ef", RUN+="/bin/raw /dev/raw/raw2 %N"

ACTION=="add", KERNEL=="sd*1", PROGRAM=="/sbin/scsi_id -g -u -s %p", RESULT=="360080e500017ff06000004054c47bd4a", RUN+="/bin/raw /dev/raw/raw3 %N"

KERNEL=="raw[1-3]", OWNER="oracle", GROUP="dba", MODE="660"

[root@ractest1 rules.d]# start_udev

Starting udev: [  OK  ]

[root@ractest1 rules.d]#

[root@ractest1 rules.d]# raw -qa

/dev/raw/raw1:  bound to major 8, minor 81

/dev/raw/raw2:  bound to major 8, minor 65

/dev/raw/raw3:  bound to major 8, minor 49

同理，在另外一台机，也进行一样的操做。

通过如上操做后，全部问题都解决了，无论怎么重启都不会有问题！