xl.conf(5)

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

6       /etc/xen/xl.conf - XL Global/Host Configuration
7

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).
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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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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.
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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.
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: 32 on hosts up to 16TB of memory, 64 on hosts larger than
71           16TB
72
73       max_maptrack_frames=NUMBER
74           Sets the default value for the "max_maptrack_frames" domain config
75           value.
76
77           Default: 1024
78
79       vif.default.script="PATH"
80           Configures the default hotplug script used by virtual network
81           devices.
82
83           The old vifscript option is deprecated and should not be used.
84
85           Default: "/etc/xen/scripts/vif-bridge"
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87       vif.default.bridge="NAME"
88           Configures the default bridge to set for virtual network devices.
89
90           The old defaultbridge option is deprecated and should not be used.
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92           Default: "xenbr0"
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94       vif.default.backend="NAME"
95           Configures the default backend to set for virtual network devices.
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97           Default: 0
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99       vif.default.gatewaydev="NAME"
100           Configures the default gateway device to set for virtual network
101           devices.
102
103           Default: "None"
104
105       remus.default.netbufscript="PATH"
106           Configures the default script used by Remus to setup network
107           buffering.
108
109           Default: "/etc/xen/scripts/remus-netbuf-setup"
110
111       colo.default.proxyscript="PATH"
112           Configures the default script used by COLO to setup colo-proxy.
113
114           Default: "/etc/xen/scripts/colo-proxy-setup"
115
116       output_format="json|sxp"
117           Configures the default output format used by xl when printing
118           "machine readable" information. The default is to use the "JSON"
119           <http://www.json.org/> syntax. However for compatibility with the
120           previous "xm" toolstack this can be configured to use the old "SXP"
121           (S-Expression-like) syntax instead.
122
123           Default: "json"
124
125       blkdev_start="NAME"
126           Configures the name of the first block device to be used for
127           temporary block device allocations by the toolstack.  The default
128           choice is "xvda".
129
130       claim_mode=BOOLEAN
131           If this option is enabled then when a guest is created there will
132           be an guarantee that there is memory available for the guest. This
133           is an particularly acute problem on hosts with memory over-
134           provisioned guests that use tmem and have self-balloon enabled
135           (which is the default option). The self-balloon mechanism can
136           deflate/inflate the balloon quickly and the amount of free memory
137           (which "xl info" can show) is stale the moment it is printed. When
138           claim is enabled a reservation for the amount of memory (see
139           'memory' in xl.conf(5)) is set, which is then reduced as the
140           domain's memory is populated and eventually reaches zero.  The free
141           memory in "xl info" is the combination of the hypervisor's free
142           heap memory minus the outstanding claims value.
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144           If the reservation cannot be meet the guest creation fails
145           immediately instead of taking seconds/minutes (depending on the
146           size of the guest) while the guest is populated.
147
148           Note that to enable tmem type guests, one needs to provide "tmem"
149           on the Xen hypervisor argument and as well on the Linux kernel
150           command line.
151
152           Default: 1
153
154           0   No claim is made. Memory population during guest creation will
155               be attempted as normal and may fail due to memory exhaustion.
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157           1   Normal memory and freeable pool of ephemeral pages (tmem) is
158               used when calculating whether there is enough memory free to
159               launch a guest.  This guarantees immediate feedback whether the
160               guest can be launched due to memory exhaustion (which can take
161               a long time to find out if launching massively huge guests).
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163       vm.cpumask="CPULIST"
164       vm.hvm.cpumask="CPULIST"
165       vm.pv.cpumask="CPULIST"
166           Global masks that are applied when creating guests and pinning
167           vcpus to indicate which cpus they are allowed to run on.
168           Specifically, "vm.cpumask" applies to all guest types,
169           "vm.hvm.cpumask" applies to both HVM and PVH guests and
170           "vm.pv.cpumask" applies to PV guests.
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172           The hard affinity of guest's vcpus are logical-AND'ed with
173           respective masks. If the resulting affinity mask is empty,
174           operation will fail.
175
176           Use --ignore-global-affinity-masks to skip applying global masks.
177
178           The default value for these masks are all 1's, i.e. all cpus are
179           allowed.
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181           Due to bug(s), these options may not interact well with other
182           options concerning CPU affinity. One example is CPU pools. Users
183           should always double check that the required affinity has taken
184           effect.
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NAME

DESCRIPTION

SYNTAX

OPTIONS

SEE ALSO