1virt-get-kernel(1) Virtualization Support virt-get-kernel(1)
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6 virt-get-kernel - Extract kernel and ramdisk from guests
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9 virt-get-kernel [--options] -d domname
10 virt-get-kernel [--options] -a disk.img
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14 This option extracts the kernel and initramfs from a guest.
15 The format of the disk image is automatically detected unless you
17 specify it by using the --format option.
18 In the case where the guest contains multiple kernels, the one with the
20 highest version number is chosen. To extract arbitrary kernels from
21 the disk image, see guestfish(1). To extract the entire "/boot"
22 directory of a guest, see virt-copy-out(1).
23
25 --help
26 Display help.
27 -a file
29 --add file
30 Add file which should be a disk image from a virtual machine.
31 The format of the disk image is auto-detected. To override this
33 and force a particular format use the --format option.
34 -a URI
36 --add URI
37 Add a remote disk. The URI format is compatible with guestfish.
38 See "ADDING REMOTE STORAGE" in guestfish(1).
39 --blocksize 512
41 --blocksize 4096
42 This parameter sets the sector size of the disk image added with -a
43 option and is ignored for libvirt guest added with -d option. See
44 also "guestfs_add_drive_opts" in guestfs(3).
45 --colors
47 --colours
48 Use ANSI colour sequences to colourize messages. This is the
49 default when the output is a tty. If the output of the program is
50 redirected to a file, ANSI colour sequences are disabled unless you
51 use this option.
52 -c URI
54 --connect URI
55 If using libvirt, connect to the given URI. If omitted, then we
56 connect to the default libvirt hypervisor.
57 If you specify guest block devices directly (-a), then libvirt is
59 not used at all.
60 -d guest
62 --domain guest
63 Add all the disks from the named libvirt guest. Domain UUIDs can
64 be used instead of names.
65 --echo-keys
67 When prompting for keys and passphrases, virt-get-kernel normally
68 turns echoing off so you cannot see what you are typing. If you
69 are not worried about Tempest attacks and there is no one else in
70 the room you can specify this flag to see what you are typing.
71 --format raw|qcow2|..
73 --format auto
74 The default for the -a option is to auto-detect the format of the
75 disk image. Using this forces the disk format for the -a option on
76 the command line.
77 If you have untrusted raw-format guest disk images, you should use
79 this option to specify the disk format. This avoids a possible
80 security problem with malicious guests (CVE-2010-3851).
81 --key SELECTOR
83 Specify a key for LUKS, to automatically open a LUKS device when
84 using the inspection. "ID" can be either the libguestfs device
85 name, or the UUID of the LUKS device.
86 --key "ID":key:KEY_STRING
88 Use the specified "KEY_STRING" as passphrase.
89 --key "ID":file:FILENAME
91 Read the passphrase from FILENAME.
92 --keys-from-stdin
94 Read key or passphrase parameters from stdin. The default is to
95 try to read passphrases from the user by opening /dev/tty.
96 If there are multiple encrypted devices then you may need to supply
98 multiple keys on stdin, one per line.
99 --machine-readable
101 --machine-readable=format
102 This option is used to make the output more machine friendly when
103 being parsed by other programs. See "MACHINE READABLE OUTPUT"
104 below.
105 -o directory
107 --output directory
108 This option specifies the output directory where kernel and
109 initramfs from the guest are written.
110 If not specified, the default output is the current directory.
112 --prefix prefix
114 This option specifies a prefix for the extracted files.
115 If a prefix is specified, then there will be a dash ("-") after the
117 prefix and before the rest of the file name; for example, a kernel
118 in the guest like "vmlinuz-3.19.0-20-generic" is saved as
119 "mydistro-vmlinuz-3.19.0-20-generic" when the prefix is "mydistro".
120 See also --unversioned-names.
122 -q
124 --quiet
125 Don’t print ordinary progress messages.
126 --unversioned-names
128 This option affects the destination file name of extracted files.
129 If enabled, files will be saved locally just with the base name;
131 for example, kernel and ramdisk in the guest like
132 "vmlinuz-3.19.0-20-generic" and "initrd.img-3.19.0-20-generic" are
133 saved respectively as "vmlinuz" and "initrd.img".
134 See also --prefix.
136 -v
138 --verbose
139 Enable verbose messages for debugging.
140 -V
142 --version
143 Display version number and exit.
144 -x Enable tracing of libguestfs API calls.
146
148 The --machine-readable option can be used to make the output more
149 machine friendly, which is useful when calling virt-get-kernel from
150 other programs, GUIs etc.
151 Use the option on its own to query the capabilities of the virt-get-
153 kernel binary. Typical output looks like this:
154 $ virt-get-kernel --machine-readable
156 virt-get-kernel
157 A list of features is printed, one per line, and the program exits with
159 status 0.
160 It is possible to specify a format string for controlling the output;
162 see "ADVANCED MACHINE READABLE OUTPUT" in guestfs(3).
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165 For other environment variables which affect all libguestfs programs,
166 see "ENVIRONMENT VARIABLES" in guestfs(3).
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169 This program returns 0 if successful, or non-zero if there was an
170 error.
171
173 guestfs(3), guestfish(1), guestmount(1), virt-copy-out(1),
174 http://libguestfs.org/.
175
177 Richard W.M. Jones http://people.redhat.com/~rjones/
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180 Copyright (C) 2013-2020 Red Hat Inc.
181
183 This program is free software; you can redistribute it and/or modify it
184 under the terms of the GNU General Public License as published by the
185 Free Software Foundation; either version 2 of the License, or (at your
186 option) any later version.
187 This program is distributed in the hope that it will be useful, but
189 WITHOUT ANY WARRANTY; without even the implied warranty of
190 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
191 General Public License for more details.
192 You should have received a copy of the GNU General Public License along
194 with this program; if not, write to the Free Software Foundation, Inc.,
195 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
196
198 To get a list of bugs against libguestfs, use this link:
199 https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
200 To report a new bug against libguestfs, use this link:
202 https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
203 When reporting a bug, please supply:
205 • The version of libguestfs.
207 • Where you got libguestfs (eg. which Linux distro, compiled from
209 source, etc)
210 • Describe the bug accurately and give a way to reproduce it.
212 • Run libguestfs-test-tool(1) and paste the complete, unedited output
214 into the bug report.
215guestfs-tools-1.47.2 2021-07-22 virt-get-kernel(1)