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是一個有效的磁盤I/O調控工具。它位於磁盤和應用層之間,並以設備的形式呈現,主要爲上層的任務分配權重,通過令牌的方式進行任務間的I/O調控。
+ +------+ +------+ +------+ +------+ +------+ +------+
+ |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
+ +--------------------------+--------------------------+
+
安裝
dm-ioband並沒有集成在mainstream kernel裏,需要打patch才能用,而且必須是kernel社區的源碼。下載patch並完成打補丁,然後make menuconfig,在lvm/raid/devicemapper下面把ioband模塊勾選上,重新編譯安裝內核,重啓之後lsmod | grep ioband,如果能看到ioband,說明安裝成功了。
+ 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
如果重啓之後,發現沒有ioband模塊,使用modprobe加載,如果仍失敗,試使用modprobe -f dm-ioband。
使用
邏輯卷創建:
# lvcreate -L size(eg. 100G) -n name(eg. LVM1) vgname(eg. vg0)
# mkfs.ext3 name 邏輯捲上創建ext3文件系統格式
另外pv和vg創建如下所示:
# pvcreate /dev/sdb
# pvcreate /dev/sdc
# vgcreate vg0 /dev/sdb /dev/sdc
ioband使用命令:
1. 創建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
以上兩條命令,分別爲邏輯卷/dev/domu/test和/de/domu/test02創建ioband1和ioband2,帶寬權重爲80:20,即任務通過test和test02使用磁盤資源時,其I/O帶寬分配比例爲80:20=4:1。
2. 調節權重
# dmsetup message ioband1 0 weight 60
# dmsetup message ioband2 0 weight 40
以上兩條命令,將ioband1和ioband2的權重調節爲60:40。
3. 查看狀態
# dmsetup table --target ioband
# dmsetup status --target ioband
以上兩條命令,可以查看當前系統中各ioband的狀態信息。
http://lwn.net/Articles/332934/
http://blog.csdn.net/majieyue/article/details/7298218