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
12
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 --machine-readable
98 --machine-readable=format
99 This option is used to make the output more machine friendly when
100 being parsed by other programs. See "MACHINE READABLE OUTPUT"
101 below.
102 -o directory
104 --output directory
105 This option specifies the output directory where kernel and
106 initramfs from the guest are written.
107 If not specified, the default output is the current directory.
109 --prefix prefix
111 This option specifies a prefix for the extracted files.
112 If a prefix is specified, then there will be a dash ("-") after the
114 prefix and before the rest of the file name; for example, a kernel
115 in the guest like "vmlinuz-3.19.0-20-generic" is saved as
116 "mydistro-vmlinuz-3.19.0-20-generic" when the prefix is "mydistro".
117 See also --unversioned-names.
119 -q
121 --quiet
122 Don’t print ordinary progress messages.
123 --unversioned-names
125 This option affects the destination file name of extracted files.
126 If enabled, files will be saved locally just with the base name;
128 for example, kernel and ramdisk in the guest like
129 "vmlinuz-3.19.0-20-generic" and "initrd.img-3.19.0-20-generic" are
130 saved respectively as "vmlinuz" and "initrd.img".
131 See also --prefix.
133 -v
135 --verbose
136 Enable verbose messages for debugging.
137 -V
139 --version
140 Display version number and exit.
141 -x Enable tracing of libguestfs API calls.
143
145 The --machine-readable option can be used to make the output more
146 machine friendly, which is useful when calling virt-get-kernel from
147 other programs, GUIs etc.
148 Use the option on its own to query the capabilities of the virt-get-
150 kernel binary. Typical output looks like this:
151 $ virt-get-kernel --machine-readable
153 virt-get-kernel
154 A list of features is printed, one per line, and the program exits with
156 status 0.
157 It is possible to specify a format string for controlling the output;
159 see "ADVANCED MACHINE READABLE OUTPUT" in guestfs(3).
160
162 For other environment variables which affect all libguestfs programs,
163 see "ENVIRONMENT VARIABLES" in guestfs(3).
164
166 This program returns 0 if successful, or non-zero if there was an
167 error.
168
170 guestfs(3), guestfish(1), guestmount(1), virt-copy-out(1),
171 http://libguestfs.org/.
172
174 Richard W.M. Jones http://people.redhat.com/~rjones/
175
177 Copyright (C) 2013-2020 Red Hat Inc.
178
180 This program is free software; you can redistribute it and/or modify it
181 under the terms of the GNU General Public License as published by the
182 Free Software Foundation; either version 2 of the License, or (at your
183 option) any later version.
184 This program is distributed in the hope that it will be useful, but
186 WITHOUT ANY WARRANTY; without even the implied warranty of
187 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
188 General Public License for more details.
189 You should have received a copy of the GNU General Public License along
191 with this program; if not, write to the Free Software Foundation, Inc.,
192 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
193
195 To get a list of bugs against libguestfs, use this link:
196 https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
197 To report a new bug against libguestfs, use this link:
199 https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
200 When reporting a bug, please supply:
202 · The version of libguestfs.
204 · Where you got libguestfs (eg. which Linux distro, compiled from
206 source, etc)
207 · Describe the bug accurately and give a way to reproduce it.
209 · Run libguestfs-test-tool(1) and paste the complete, unedited output
211 into the bug report.
212libguestfs-1.42.0 2020-03-09 virt-get-kernel(1)