1xl.conf(5)                            Xen                           xl.conf(5)
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NAME

6       /etc/xen/xl.conf - XL Global/Host Configuration
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DESCRIPTION

9       The xl.conf file allows configuration of hostwide "xl" toolstack
10       options.
11
12       For details of per-domain configuration options please see xl.cfg(5).
13

SYNTAX

15       The config file consists of a series of "KEY=VALUE" pairs.
16
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).
25
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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OPTIONS

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.
40
41           If set to "off" then "xl" will not automatically reduce the amount
42           of domain 0 memory.
43
44           If set to "auto" then auto-ballooning will be disabled if the
45           "dom0_mem" option was provided on the Xen command line.
46
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.
50
51           Default: "auto"
52
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.
57
58           Default: 1
59
60       lockfile="PATH"
61           Sets the path to the lock file used by xl to serialise certain
62           operations (primarily domain creation).
63
64           Default: "/var/lock/xl"
65
66       max_grant_frames=NUMBER
67           Sets the default value for the "max_grant_frames" domain config
68           value.
69
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.
76
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.
83
84           The old vifscript option is deprecated and should not be used.
85
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.
90
91           The old defaultbridge option is deprecated and should not be used.
92
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.
103
104           Default: "None"
105
106       remus.default.netbufscript="PATH"
107           Configures the default script used by Remus to setup network
108           buffering.
109
110           Default: "/etc/xen/scripts/remus-netbuf-setup"
111
112       colo.default.proxyscript="PATH"
113           Configures the default script used by COLO to setup colo-proxy.
114
115           Default: "/etc/xen/scripts/colo-proxy-setup"
116
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.
123
124           Default: "json"
125
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".
130
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.
141
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.
145
146           Default: 1
147
148           0   No claim is made. Memory population during guest creation will
149               be attempted as normal and may fail due to memory exhaustion.
150
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.
165
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.
169
170           Use --ignore-global-affinity-masks to skip applying global masks.
171
172           The default value for these masks are all 1's, i.e. all cpus are
173           allowed.
174
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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SEE ALSO

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)
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