给iscsi盘指定固定的设备名
登入 iSCSI Target 之後我�����l�F多出��深w硬碟,不管是大小�是��B都一��,�@就是 iSCSI Initiator 已�和 Target 端透�^��l路�浇�立了不同的�B�.接下�砭托枰��O定一下所�^的 MPIO , 在 Linux 下是被�Q�� device-mapper multipath
[root@benjr ~]# fdisk -l
Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 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 60801 488279610 8e Linux LVM
Disk /dev/sdb: 20.0 GB, 20012106240 bytes
64 heads, 32 sectors/track, 19085 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
Disk /dev/sdc: 20.0 GB, 20012106240 bytes
64 heads, 32 sectors/track, 19085 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
DM(Device-Mapper) multipath 的�O定�n�Υ嬖� /etc/multipath.conf ,我��只需要�⑾到y�A�O的 blacklist - devnode,�⑺�用 "#"�]解掉.�系�y自己���y即可.
[root@benjr ~]# vi /etc/multipath.conf
blacklist {
# devnode "*"
}
DM(Device-Mapper) multipath 的服�彰��Q�� multipathd ,�_�C���r�O定 chkconfig ,立即�⒂梅��帐褂� service 程式.
[root@benjr ~]# chkconfig multipathd on
Start multipathd:
[root@benjr ~]# service multipathd start
List multipath devices:
��我�� "multipathd" 的服���又�後使用 multipath 指定�碛^看可以�l�F����由 iSCSI Initiator �B�所建立出�淼� 2 �w硬碟已�其��是指向同一�� SCSI ID 而 DM-Multipath 也�_�J的出��.
[root@benjr ~]# multipath -ll
mpath1 (16465616462656166313a3100000000000000000000000000) dm-2 IET,VIRTUAL-DISK
[size=19G][features=0][hwhandler=0]
\_ round-robin 0 [prio=1][active]
\_ 7:0:0:1 sdb 8:16 [active][ready]
\_ round-robin 0 [prio=1][enabled]
\_ 6:0:0:1 sdc 8:32 [active][ready]
我��也可以透�^指令 scsi_id ��z�硬碟�b置的 ID 是否相同.
[root@benjr ~]# scsi_id -x -g -u -s /block/sdb
ID_VENDOR=IET
ID_MODEL=VIRTUAL-DISK
ID_REVISION=0001
ID_SERIAL=16465616462656166313a3100000000000000000000000000
ID_TYPE=disk
ID_BUS=scsi
[root@benjr ~]# scsi_id -x -g -u -s /block/sdc
ID_VENDOR=IET
ID_MODEL=VIRTUAL-DISK
ID_REVISION=0001
ID_SERIAL=16465616462656166313a3100000000000000000000000000
ID_TYPE=disk
ID_BUS=scsi
我��透�^系�y就可以�^看到 /dev/dm 的�b置了.�@���b置就如同一般的硬碟�b置,如同 /dev/sda 你可以��λ�做分割,格式化,�x��等�幼�.而且�具�� MPIO 的功能.
[root@benjr ~]# fdisk -l
Disk /dev/dm-2: 20.0 GB, 20012106240 bytes
255 heads, 63 sectors/track, 2433 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/dm-2p1 * 1 13 104391 83 Linux
/dev/dm-2p2 14 2433 19438650 8e Linux LVM
如果系�y�]有自�赢a生 /dev/dm 的�b置�r可以透�^程式 kpartx �懋a生.
[root@benjr ~]# kpartx -a /dev/mapper/16465616462656166313a3100000000000000000000000000