qemu/docs/throttle.txt

11 QEMU includes a throttling module that can be used to set limits to
24 them the user can set a global limit or separate limits for read and
27 I/O limits can be set using the throttling.* parameters of -drive, or
42 It is possible to set limits for both IOPS and bps at the same time,
44 write limits or not, but note that if iops-total is set then neither
73 In addition to the basic limits we have just seen, QEMU allows the
78 limits lower the rest of the time.
144 When applying IOPS limits all I/O operations are treated equally
146 of this in order to circumvent the limits and submit one huge I/O
160 requests is never taken into account when applying IOPS limits.
163 Applying I/O limits to groups of disks
165 In all the examples so far we have seen how to apply limits to the I/O
167 they all share the same limits.
169 The way it works is that each drive with I/O limits is assigned to a
194 When I/O limits are applied to an existing drive using the QMP command
198    - I/O limits are shared within the same group, so new values will
200      words: if different limits are applied to members of the same
208      it was member of a different one. In this case the limits
212    - I/O limits can be disabled by setting all of them to 0. In this
220 I/O limits in QEMU are implemented using the leaky bucket algorithm
260 Since QEMU 2.11 it is possible to configure the I/O limits using a
266 them must be assigned to a group that contains the actual I/O limits.
267 Different filters can use the same group so the limits are shared as
268 described earlier in "Applying I/O limits to groups of disks".
276        "limits" : {
283 throttle-group has a 'limits' property (of type ThrottleLimits as
288 option but at the moment there is no way to pass a 'limits' parameter
296 enables use of 'limits'.
331 that we have three different drives and we want to set I/O limits for
332 each one of them and an additional set of limits for the combined I/O
357 In this example the individual drives have IOPS limits of 2000, 2500