iSCSI volume 扩容

环境：Ubuntu 12.04 Server

192.168.0.203安装:apt-get install tgt  提供存储   (redhad :$yum install scsi-target-utils)

192.168.0.204安装：apt-get intall openiscsi  使用203提供的存储的计算节点

 

203建立了一个mycloud的lv供客户端192.168.0.204使用，这里事先配置好了lv 叫mycloud，下面是/etc/tgt/target.conf 文件。

 

<target mycloud>

backing-store /dev/iscsi/mycloud

</target>

 

root@203:~# lvs
  LV        VG      Attr   LSize   Origin Snap%  Move Log Copy%  Convert
  mycloud   iscsi   -wi-ao 126.00g
  root      ubuntu  -wi-ao  52.25g

 

在客户端192.168.0.204运行discovery 和login

 

root@204:/opt# iscsiadm -m discovery -t st -p 192.168.0.203
192.168.0.203:3260,1 mycloud

 root@204:/opt# iscsiadm -m node -T mycloud -p 192.168.0.203 -l

 

Logging in to [iface: default, target: mycloud, portal: 192.168.0.203,3260]
Login to [iface: default, target: mycloud, portal: 192.168.0.203,3260]: successful

 

....省略
Disk /dev/sdc: 135.3 GB, 135291469824 bytes
255 heads, 63 sectors/track, 16448 cylinders, total 264241152 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 identifier: 0x00000000

Disk /dev/sdc doesn't contain a valid partition table

现在我们对203的LV mycloud扩大容量

 

root@203:~# lvextend -L +50G /dev/iscsi/mycloud
  Extending logical volume mycloud to 176.00 GiB
  Logical volume mycloud successfully resized

 

tgt-admin --show 查看LUN (Logical Unit ) ，Size并没有随LV扩大

 

Target 1: mycloud
    System information:
        Driver: iscsi
        State: ready
    I_T nexus information:
        I_T nexus: 2
            Initiator: iqn.1993-08.org.debian:01:0ba3721998
            Connection: 0
                IP Address: 192.168.0.204
    LUN information:
        LUN: 0
            Type: controller
            SCSI ID: IET     00010000
            SCSI SN: beaf10
            Size: 0 MB, Block size: 1
            Online: Yes
            Removable media: No
            Readonly: No
            Backing store type: null
            Backing store path: None
            Backing store flags:
        LUN: 1
            Type: disk
            SCSI ID: IET     00010001
            SCSI SN: beaf11
            Size: 135291 MB, Block size: 512
            Online: Yes
            Removable media: No
            Readonly: No
            Backing store type: rdwr
            Backing store path: /dev/iscsi/mycloud
            Backing store flags:
    Account information:
    ACL information:
        ALL

 

 

首先要删除LUN 映射，这里不是真正删除，只是删除与内核的映射关系

 

root@203:~# tgtadm --op delete --mode logicalunit --tid=1 --lun=1

 

 重新创建：

 

root@203:~# tgtadm --op new --mode logicalunit --tid=1 --lun=1  \
--backing-store=/dev/iscsi/mycloud 

 再来看其Size：

 

root@204:tgt-admin --show

  LUN: 1
            Type: disk
            SCSI ID: IET     00010001
            SCSI SN: beaf11
            Size: 188979 MB, Block size: 512
            Online: Yes
            Removable media: No
            Readonly: No
            Backing store type: rdwr
            Backing store path: /dev/iscsi/mycloud
            Backing store flags:
    Account information:

 

最后一步在204重新扫描：

 

root@204:/opt# iscsiadm --mode node --targetname mycloud -R
Rescanning session [sid: 3, target: mycloud, portal: 192.168.0.203,3260]

 

再fdisk -l 比对之前的sdc 大小：

 

Disk /dev/sdc: 189.0 GB, 188978561024 bytes
255 heads, 63 sectors/track, 22975 cylinders, total 369098752 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 identifier: 0x00000000

 

如果sdc 又当做是作为了lvm，那么要更新PV

 

pvresize -v /dev/disk/by-path/ip-192.168.0.203\:3260-iscsi-mycloud-lun-1

 

 或者

 

pvresize -v /dev/sdc

 

 

如果关联的libvirt，那么还要pool-refresh 一下，这样才能在pool中看到更新后的大小。

 

参考：http://www.outsidaz.org/blog/2011/08/08/resizing-iscsi-volumes-using-tgtd-iscsiadm-on-rhel5rhel6/

 

搞定！

 

补充：

在discovery 的时候出现 iscaiadm: Could not perform SendTargets discovery

 

原因可能有：该机器只安装了open-iscsi-utils,并没有安装open-iscsi

 

iscsi logout 后  出现的

 

/dev/dm-9: read failed after 0 of 4096 at 0: Input/output error

 

 可以使用命令：

 

dmsetup remove /dev/dm-9

 删除之