ioband
dm-ioband is an I/O bandwidth controller implemented as a device-mapper driver. Several jobs using the same block device have to share the bandwidth of the device. dm-ioband gives bandwidth to each job according to its weight, which each job can set its own value to.
dm-ioband是一个有效的磁盘I/O调控工具。它位于磁盘和应用层之间,并以设备的形式呈现,主要为上层的任务分配权重,通过令牌的方式进行任务间的I/O调控。
+ +------+ +------+ +------+ +------+ +------+ +------+
+ |cgroup| |cgroup| | the | | pid | | pid | | the | jobs
+ | A | | B | |others| | X | | Y |
|others|
+ +--|---+ +--|---+ +--|---+ +--|---+ +--|---+ +--|---+
+ +--V----+---V---+----V---+ +--V----+---V---+----V---+
+ | group | group | default| | group | group | default| ioband groups
+ | | | group | | | | group
|
+ +-------+-------+--------+ +-------+-------+--------+
+ | ioband1 | | ioband2 | ioband
devices
+ +-----------|------------+ +-----------|------------+
+ +-----------V--------------+-------------V------------+
+ | | |
+ | sdb1 | sdb2 | block
devices
+ +--------------------------+--------------------------+
+
安装
dm-ioband并没有集成在mainstream kernel里,需要打patch才能用,而且必须是kernel社区的源码。下载patch并完成打补丁,然后make menuconfig,在lvm/raid/devicemapper下面把ioband模块勾选上,重新编译安装内核,重启之后lsmod | grep ioband,如果能看到ioband,说明安装成功了。
+ Build a kernel with these options enabled:
+
+ CONFIG_MD
+ CONFIG_BLK_DEV_DM
+ CONFIG_DM_IOBAND
+
+
+ If compiled as module, use modprobe to load dm-ioband.
+
+ # make modules
+ # make modules_install
+ # depmod -a
+ # modprobe dm-ioband
+
+
+ "dmsetup targets" command shows all available device-mapper targets.
+ "ioband" and the version number are displayed when dm-ioband has been
+ loaded.
+
+ # dmsetup targets | grep ioband
+ ioband v1.0.0
如果重启之后,发现没有ioband模块,使用modprobe加载,如果仍失败,试使用modprobe -f dm-ioband。
使用
逻辑卷创建:
# lvcreate -L size(eg. 100G) -n name(eg. LVM1) vgname(eg. vg0)
# mkfs.ext3 name 逻辑卷上创建ext3文件系统格式
另外pv和vg创建如下所示:
# pvcreate /dev/sdb
# pvcreate /dev/sdc
# vgcreate vg0 /dev/sdb /dev/sdc
ioband使用命令:
1. 创建ioband
#echo "0 $(blockdev --getsize /dev/domu/test) ioband /dev/domu/test 1 0 0 none weight 0 :80" | dmsetup create ioband1
#echo "0 $(blockdev --getsize /dev/domu/test02) ioband /dev/domu/test02 1 0 0 none weight 0 :20" | dmsetup create ioband2
以上两条命令,分别为逻辑卷/dev/domu/test和/de/domu/test02创建ioband1和ioband2,带宽权重为80:20,即任务通过test和test02使用磁盘资源时,其I/O带宽分配比例为80:20=4:1。
2. 调节权重
# dmsetup message ioband1 0 weight 60
# dmsetup message ioband2 0 weight 40
以上两条命令,将ioband1和ioband2的权重调节为60:40。
3. 查看状态
# dmsetup table --target ioband
# dmsetup status --target ioband
以上两条命令,可以查看当前系统中各ioband的状态信息。
http://lwn.net/Articles/332934/
http://blog.csdn.net/majieyue/article/details/7298218