This is the patch file for range-bw documentation From: Dong-Jae Kang <djkang@xxxxxxxxxx> or <baramsori72@xxxxxxxxx> Range-BW is an I/O controller supports the process group-based range bandwidth according to the priority or importance of the group. Range bandwidth means the predicable I/O bandwidth with minimum and maximum value defined by administrator. Signed-off-by: Dong-Jae Kang <baramsori72@xxxxxxxxx> Signed-off-by: Chei-Yol Kim <gauri@xxxxxxxxxx> =========================================================================================== diff -urN linux-2.6.29-orig/Documentation/device-mapper/range-bw.txt linux-2.6.29-patch/Documentation/device-mapper/range-bw.txt --- linux-2.6.29-orig/Documentation/device-mapper/range-bw.txt 1970-01-01 09:00:00.000000000 +0900 +++ linux-2.6.29-patch/Documentation/device-mapper/range-bw.txt 2009-05-04 15:38:02.000000000 +0900 @@ -0,0 +1,91 @@ +Range-BW I/O controller by Dong-Jae Kang <djkang@xxxxxxxxxx> + + +1. Introduction +=============== + +The design of Range-BW is related with three another parts, Cgroup, bio-cgroup (or blkio-cgroup) and dm-ioband +and it was implemented as an additional controller for dm-ioband. +Cgroup framework is used to support process grouping mechanism and bio-cgroup is used to control delayed I/O or +non-direct I/O. Finally, dm-ioband is a kind of I/O controller allowing the proportional I/O bandwidth +to process groups based on its priority. +The supposed controller supports the process group-based range bandwidth according to the priority or +importance of the group. Range bandwidth means the predicable I/O bandwidth with minimum and maximum value +defined by administrator. + +Minimum I/O bandwidth should be guaranteed for stable performance or reliability of specific service +and I/O bandwidth over maximum should be throttled to protect the limited I/O resource from over-provisioning +in unnecessary usage or to reserve the I/O bandwidth for another use. +So, Range-BW was implemented to include the two concepts, guaranteeing of minimum I/O requirement +and limitation of unnecessary bandwidth depending on its priority. +And it was implemented as device mapper driver such like dm-ioband. +So, it is independent of the underlying specific I/O scheduler, for example, CFQ, AS, NOOP, deadline and so on. + +Range-BW has two kinds of operation modes, min-max and max mode. Min-max mode is to supports guaranteeing +the minimum I/O requirement and limitation of unnecessary I/O bandwidth at the same time. +And max mode is to support only limitation. So in case of min-max mode, you need to configure min-bw +and max-bw values and in case of max mode, configure only max-bw. + +* Attention +Range-BW supports the predicable I/O bandwidth, but it should be configured in the scope of total I/O bandwidth +of the I/O system to guarantee the minimum I/O requirement. For example, if total I/O bandwidth is 40Mbytes/sec, +the summary of I/O bandwidth configured in each process group should be equal or smaller than 40Mbytes/sec. +So, we need to check total I/O bandwidth before set it up. + +2. Setup and Installation +========================= + +This part is same with dm-ioband, ../../Documentation/device-mapper/ioband.txt or +http://people.valinux.co.jp/~ryov/dm-ioband/manual/setup.html +You must first install the appropriate bio-cgroup and dm-ioband patches before using range-bw patch. + +3. Usage +======== + +It is very useful to refer the documentation for dm-ioband in ../../Documentation/device-mapper/ioband.txt or +http://people.valinux.co.jp/~ryov/dm-ioband/, because Range-BW follows the basic semantics of dm-ioband. +This example is for min-max mode. + +# mount the cgroup +mount -t cgroup -o bio none /root/cgroup/bio + +# create the process groups (3 groups) +mkdir /root/cgroup/bio/bgroup1 +mkdir /root/cgroup/bio/bgroup2 +mkdir /root/cgroup/bio/bgroup3 + +# create the ioband device ( name : ioband1 ) +echo "0 $(blockdev --getsize /dev/sdb2) ioband /dev/sdb2 1 0 0 none +range-bw 0 :0" | dmsetup create ioband1 +: device name (/dev/sdb2) should be modified depending on your system + +# init ioband device ( type and policy ) +dmsetup message ioband1 0 type cgroup +dmsetup message ioband1 0 policy range-bw + +# attach the groups to the ioband device +dmsetup message ioband1 0 attach 2 +dmsetup message ioband1 0 attach 3 +dmsetup message ioband1 0 attach 4 +: group number can be referred in /root/cgroup/bio/bgroup1/bio.id + +# allocate the values ( min-bw and max-bw ) : XXX Kbytes +: the sum of minimum I/O bandwidth in each group should be equal or smaller than total bandwidth + to be supported by your system + +# range : about 100~500 Kbytes +dmsetup message ioband1 0 min-bw 2:100 +dmsetup message ioband1 0 max-bw 2:500 + +# range : about 700~1000 Kbytes +dmsetup message ioband1 0 min-bw 3:700 +dmsetup message ioband1 0 max-bw 3:1000 + +# range : about 50~60Mbytes +dmsetup message ioband1 0 min-bw 4:50000 +dmsetup message ioband1 0 max-bw 4:60000 + +You can confirm the configuration of range-bw by using this command : +[root@localhost range-bw]# dmsetup table --target ioband +ioband1: 0 305235000 ioband 8:18 1 4 128 cgroup range-bw 16384 :0 2:100:500 3:700:1000 4:30000:60000 + -- Best Regards, Dong-Jae Kang _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
