1xl.conf(5) Xen xl.conf(5)
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6 /etc/xen/xl.conf - XL Global/Host Configuration
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9 The xl.conf file allows configuration of hostwide "xl" toolstack
10 options.
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12 For details of per-domain configuration options please see xl.cfg(5).
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15 The config file consists of a series of "KEY=VALUE" pairs.
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17 A value "VALUE" is one of:
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19 "STRING"
20 A string, surrounded by either single or double quotes.
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22 NUMBER
23 A number, in either decimal, octal (using a 0 prefix) or
24 hexadecimal (using an "0x" prefix).
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26 BOOLEAN
27 A "NUMBER" interpreted as "False" (0) or "True" (any other value).
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29 [ VALUE, VALUE, ... ]
30 A list of "VALUES" of the above types. Lists are homogeneous and
31 are not nested.
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33 The semantics of each "KEY" defines which form of "VALUE" is required.
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36 autoballoon="off"|"on"|"auto"
37 If set to "on" then "xl" will automatically reduce the amount of
38 memory assigned to domain 0 in order to free memory for new
39 domains.
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41 If set to "off" then "xl" will not automatically reduce the amount
42 of domain 0 memory.
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44 If set to "auto" then auto-ballooning will be disabled if the
45 "dom0_mem" option was provided on the Xen command line.
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47 You are strongly recommended to set this to "off" (or "auto") if
48 you use the "dom0_mem" hypervisor command line to reduce the amount
49 of memory given to domain 0 by default.
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51 Default: "auto"
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53 run_hotplug_scripts=BOOLEAN
54 If disabled hotplug scripts will be called from udev, as it used to
55 be in the previous releases. With the default option, hotplug
56 scripts will be launched by xl directly.
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58 Default: 1
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60 lockfile="PATH"
61 Sets the path to the lock file used by xl to serialise certain
62 operations (primarily domain creation).
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64 Default: "/var/lock/xl"
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66 max_grant_frames=NUMBER
67 Sets the default value for the "max_grant_frames" domain config
68 value.
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70 Default: value of Xen command line gnttab_max_frames parameter (or
71 its default value if unspecified).
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73 max_maptrack_frames=NUMBER
74 Sets the default value for the "max_maptrack_frames" domain config
75 value.
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77 Default: value of Xen command line gnttab_max_maptrack_frames
78 parameter (or its default value if unspecified).
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80 vif.default.script="PATH"
81 Configures the default hotplug script used by virtual network
82 devices.
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84 The old vifscript option is deprecated and should not be used.
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86 Default: "/etc/xen/scripts/vif-bridge"
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88 vif.default.bridge="NAME"
89 Configures the default bridge to set for virtual network devices.
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91 The old defaultbridge option is deprecated and should not be used.
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93 Default: "xenbr0"
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95 vif.default.backend="NAME"
96 Configures the default backend to set for virtual network devices.
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98 Default: 0
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100 vif.default.gatewaydev="NAME"
101 Configures the default gateway device to set for virtual network
102 devices.
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104 Default: "None"
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106 remus.default.netbufscript="PATH"
107 Configures the default script used by Remus to setup network
108 buffering.
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110 Default: "/etc/xen/scripts/remus-netbuf-setup"
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112 colo.default.proxyscript="PATH"
113 Configures the default script used by COLO to setup colo-proxy.
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115 Default: "/etc/xen/scripts/colo-proxy-setup"
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117 output_format="json|sxp"
118 Configures the default output format used by xl when printing
119 "machine readable" information. The default is to use the "JSON"
120 <https://www.json.org/> syntax. However for compatibility with the
121 previous "xm" toolstack this can be configured to use the old "SXP"
122 (S-Expression-like) syntax instead.
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124 Default: "json"
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126 blkdev_start="NAME"
127 Configures the name of the first block device to be used for
128 temporary block device allocations by the toolstack. The default
129 choice is "xvda".
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131 claim_mode=BOOLEAN
132 If this option is enabled then when a guest is created there will
133 be an guarantee that there is memory available for the guest. The
134 self-balloon mechanism can deflate/inflate the balloon quickly and
135 the amount of free memory (which "xl info" can show) is stale the
136 moment it is printed. When claim is enabled a reservation for the
137 amount of memory (see 'memory' in xl.conf(5)) is set, which is then
138 reduced as the domain's memory is populated and eventually reaches
139 zero. The free memory in "xl info" is the combination of the
140 hypervisor's free heap memory minus the outstanding claims value.
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142 If the reservation cannot be meet the guest creation fails
143 immediately instead of taking seconds/minutes (depending on the
144 size of the guest) while the guest is populated.
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146 Default: 1
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148 0 No claim is made. Memory population during guest creation will
149 be attempted as normal and may fail due to memory exhaustion.
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151 1 Free memory as reported by the hypervisor is used for
152 calculating whether there is enough memory free to launch a
153 guest. This guarantees immediate feedback whether the guest
154 can be launched due to memory exhaustion (which can take a long
155 time to find out if launching massively huge guests).
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157 vm.cpumask="CPULIST"
158 vm.hvm.cpumask="CPULIST"
159 vm.pv.cpumask="CPULIST"
160 Global masks that are applied when creating guests and pinning
161 vcpus to indicate which cpus they are allowed to run on.
162 Specifically, "vm.cpumask" applies to all guest types,
163 "vm.hvm.cpumask" applies to both HVM and PVH guests and
164 "vm.pv.cpumask" applies to PV guests.
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166 The hard affinity of guest's vcpus are logical-AND'ed with
167 respective masks. If the resulting affinity mask is empty,
168 operation will fail.
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170 Use --ignore-global-affinity-masks to skip applying global masks.
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172 The default value for these masks are all 1's, i.e. all cpus are
173 allowed.
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175 Due to bug(s), these options may not interact well with other
176 options concerning CPU affinity. One example is CPU pools. Users
177 should always double check that the required affinity has taken
178 effect.
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181 xl(1)
182 xl.cfg(5)
183 https://www.json.org/
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1874.13.0 2020-04-14 xl.conf(5)