From e43d4f9f0207b8eb420b14b6c423ce2b0ee70517 Mon Sep 17 00:00:00 2001
From: Apollon Oikonomopoulos <apollon@noc.grnet.gr>
Date: Mon, 31 May 2010 14:28:47 +0300
Subject: [PATCH] KVM: Migration bandwidth and downtime control
Introduce 2 new hypervisor options, migration_bandwidth and migration_downtime
and implement KVM migration bandwidth and downtime control.
migration_bandwidth controls KVM's maximal bandwidth during migration, in
MiB/s. Default value is 32 MiB/s, same as KVM's internal default. This option
is a global hypervisor option.
migration_downtime sets the amount of time (in ms) a KVM instance is allowed to
freeze while copying memory pages. This is useful when migrating busy guests,
as KVM's internal default of 30ms is too low for the page-copying algorithm to
converge. This is a per-instance option, with a default of 30ms, same as KVM's
internal default.
Signed-off-by: Apollon Oikonomopoulos <apollon@noc.grnet.gr>
Signed-off-by: Balazs Lecz <leczb@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>
---
lib/constants.py | 7 +++++++
lib/hypervisor/hv_kvm.py | 10 ++++++++++
man/gnt-cluster.sgml | 15 +++++++++++++++
man/gnt-instance.sgml | 18 ++++++++++++++++++
4 files changed, 50 insertions(+)
diff --git a/lib/constants.py b/lib/constants.py
index e13d82c97..2fbc02575 100644
--- a/lib/constants.py
+++ b/lib/constants.py
@@ -434,6 +434,8 @@ HV_USB_MOUSE = "usb_mouse"
HV_DEVICE_MODEL = "device_model"
HV_INIT_SCRIPT = "init_script"
HV_MIGRATION_PORT = "migration_port"
+HV_MIGRATION_BANDWIDTH = "migration_bandwidth"
+HV_MIGRATION_DOWNTIME = "migration_downtime"
HV_USE_LOCALTIME = "use_localtime"
HV_DISK_CACHE = "disk_cache"
HV_SECURITY_MODEL = "security_model"
@@ -465,6 +467,8 @@ HVS_PARAMETER_TYPES = {
HV_DEVICE_MODEL: VTYPE_STRING,
HV_INIT_SCRIPT: VTYPE_STRING,
HV_MIGRATION_PORT: VTYPE_INT,
+ HV_MIGRATION_BANDWIDTH: VTYPE_INT,
+ HV_MIGRATION_DOWNTIME: VTYPE_INT,
HV_USE_LOCALTIME: VTYPE_BOOL,
HV_DISK_CACHE: VTYPE_STRING,
HV_SECURITY_MODEL: VTYPE_STRING,
@@ -732,6 +736,8 @@ HVC_DEFAULTS = {
HV_DISK_TYPE: HT_DISK_PARAVIRTUAL,
HV_USB_MOUSE: '',
HV_MIGRATION_PORT: 8102,
+ HV_MIGRATION_BANDWIDTH: 32, # MiB/s
+ HV_MIGRATION_DOWNTIME: 30, # ms
HV_USE_LOCALTIME: False,
HV_DISK_CACHE: HT_CACHE_DEFAULT,
HV_SECURITY_MODEL: HT_SM_NONE,
@@ -748,6 +754,7 @@ HVC_DEFAULTS = {
HVC_GLOBALS = frozenset([
HV_MIGRATION_PORT,
+ HV_MIGRATION_BANDWIDTH,
])
BEC_DEFAULTS = {
diff --git a/lib/hypervisor/hv_kvm.py b/lib/hypervisor/hv_kvm.py
index af04dcacb..51fa10f22 100644
--- a/lib/hypervisor/hv_kvm.py
+++ b/lib/hypervisor/hv_kvm.py
@@ -78,6 +78,8 @@ class KVMHypervisor(hv_base.BaseHypervisor):
constants.HV_USB_MOUSE:
hv_base.ParamInSet(False, constants.HT_KVM_VALID_MOUSE_TYPES),
constants.HV_MIGRATION_PORT: hv_base.NET_PORT_CHECK,
+ constants.HV_MIGRATION_BANDWIDTH: hv_base.NO_CHECK,
+ constants.HV_MIGRATION_DOWNTIME: hv_base.NO_CHECK,
constants.HV_USE_LOCALTIME: hv_base.NO_CHECK,
constants.HV_DISK_CACHE:
hv_base.ParamInSet(True, constants.HT_VALID_CACHE_TYPES),
@@ -811,6 +813,14 @@ class KVMHypervisor(hv_base.BaseHypervisor):
if not live:
self._CallMonitorCommand(instance_name, 'stop')
+ migrate_command = ('migrate_set_speed %dm' %
+ instance.hvparams[constants.HV_MIGRATION_BANDWIDTH])
+ self._CallMonitorCommand(instance_name, migrate_command)
+
+ migrate_command = ('migrate_set_downtime %dms' %
+ instance.hvparams[constants.HV_MIGRATION_DOWNTIME])
+ self._CallMonitorCommand(instance_name, migrate_command)
+
migrate_command = 'migrate -d tcp:%s:%s' % (target, port)
self._CallMonitorCommand(instance_name, migrate_command)
diff --git a/man/gnt-cluster.sgml b/man/gnt-cluster.sgml
index 5de8cc116..13f4f7bb6 100644
--- a/man/gnt-cluster.sgml
+++ b/man/gnt-cluster.sgml
@@ -419,6 +419,21 @@
</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term>migration_bandwidth</term>
+ <listitem>
+ <simpara>Valid for the KVM hypervisor.</simpara>
+
+ <para>
+ This option specifies the maximum bandwidth that KVM will
+ use for instance live migrations. The value is in MiB/s.
+ </para>
+
+ <simpara>This option is only effective with kvm versions >= 78
+ and qemu-kvm versions >= 0.10.0.
+ </simpara>
+ </listitem>
+ </varlistentry>
</variablelist>
</para>
diff --git a/man/gnt-instance.sgml b/man/gnt-instance.sgml
index 2cf24af14..44dd9ffea 100644
--- a/man/gnt-instance.sgml
+++ b/man/gnt-instance.sgml
@@ -658,6 +658,24 @@
</listitem>
</varlistentry>
+ <varlistentry>
+ <term>migration_downtime</term>
+ <listitem>
+ <simpara>Valid for the KVM hypervisor.</simpara>
+
+ <simpara>The maximum amount of time (in ms) a KVM instance is
+ allowed to be frozen during a live migration, in order to copy
+ dirty memory pages. Default value is 30ms, but you may need to
+ increase this value for busy instances.
+ </simpara>
+
+ <simpara>This option is only effective with kvm versions >= 87
+ and qemu-kvm versions >= 0.11.0.
+ </simpara>
+
+ </listitem>
+ </varlistentry>
+
</variablelist>
</para>
--
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