virt-log(1)

1virt-log(1)                 Virtualization Support                 virt-log(1)
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NAME

6       virt-log - Display log files from a virtual machine
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SYNOPSIS

9        virt-log [--options] -d domname
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11        virt-log [--options] -a disk.img [-a disk.img ...]
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DESCRIPTION

14       "virt-log" is a command line tool to display the log files from the
15       named virtual machine (or disk image).
16
17       This tool understands and displays both plain text log files (eg.
18       /var/log/messages) and binary formats such as the systemd journal.
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20       To display other types of files, use virt-cat(1).  To follow (tail)
21       text log files, use virt-tail(1).  To copy files out of a virtual
22       machine, use virt-copy-out(1).  To display the contents of the Windows
23       Registry, use virt-win-reg(1).
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EXAMPLES

26       Display the complete logs from a guest:
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28        virt-log -d mydomain | less
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30       Find out what DHCP IP address a VM acquired:
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32        virt-log -d mydomain | grep 'dhclient.*bound to'
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OPTIONS

35       --help
36           Display brief help.
37
38       -a file
39       --add file
40           Add file which should be a disk image from a virtual machine.  If
41           the virtual machine has multiple block devices, you must supply all
42           of them with separate -a options.
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44           The format of the disk image is auto-detected.  To override this
45           and force a particular format use the --format=.. option.
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47       -a URI
48       --add URI
49           Add a remote disk.  See "ADDING REMOTE STORAGE" in guestfish(1).
50
51       --blocksize=512
52       --blocksize=4096
53       --blocksize
54           This parameter sets the sector size of the disk image.  It affects
55           all explicitly added subsequent disks after this parameter.  Using
56           --blocksize with no argument switches the disk sector size to the
57           default value which is usually 512 bytes.  See also
58           "guestfs_add_drive_opts" in guestfs(3).
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60       -c URI
61       --connect URI
62           If using libvirt, connect to the given URI.  If omitted, then we
63           connect to the default libvirt hypervisor.
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65           If you specify guest block devices directly (-a), then libvirt is
66           not used at all.
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68       -d guest
69       --domain guest
70           Add all the disks from the named libvirt guest.  Domain UUIDs can
71           be used instead of names.
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73       --echo-keys
74           When prompting for keys and passphrases, virt-log normally turns
75           echoing off so you cannot see what you are typing.  If you are not
76           worried about Tempest attacks and there is no one else in the room
77           you can specify this flag to see what you are typing.
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79       --format=raw|qcow2|..
80       --format
81           The default for the -a option is to auto-detect the format of the
82           disk image.  Using this forces the disk format for -a options which
83           follow on the command line.  Using --format with no argument
84           switches back to auto-detection for subsequent -a options.
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86           For example:
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88            virt-log --format=raw -a disk.img
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90           forces raw format (no auto-detection) for disk.img.
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92            virt-log --format=raw -a disk.img --format -a another.img
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94           forces raw format (no auto-detection) for disk.img and reverts to
95           auto-detection for another.img.
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97           If you have untrusted raw-format guest disk images, you should use
98           this option to specify the disk format.  This avoids a possible
99           security problem with malicious guests (CVE-2010-3851).
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101       --key SELECTOR
102           Specify a key for LUKS, to automatically open a LUKS device when
103           using the inspection.
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105           --key NAME:key:KEY_STRING
106           --key UUID:key:KEY_STRING
107           --key all:key:KEY_STRING
108               "NAME" is the libguestfs device name (eg. "/dev/sda1").  "UUID"
109               is the device UUID.  "all" means try the key against any
110               encrypted device.
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112               Use the specified "KEY_STRING" as passphrase.
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114           --key NAME:file:FILENAME
115           --key UUID:file:FILENAME
116           --key all:file:FILENAME
117               Read the passphrase from FILENAME.
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119           --key NAME:clevis
120           --key UUID:clevis
121           --key all:clevis
122               Attempt passphrase-less unlocking for the device with Clevis,
123               over the network.  Please refer to "ENCRYPTED DISKS" in
124               guestfs(3) for more information on network-bound disk
125               encryption (NBDE).
126
127               Note that if any such option is present on the command line,
128               QEMU user networking will be automatically enabled for the
129               libguestfs appliance.
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131       --keys-from-stdin
132           Read key or passphrase parameters from stdin.  The default is to
133           try to read passphrases from the user by opening /dev/tty.
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135           If there are multiple encrypted devices then you may need to supply
136           multiple keys on stdin, one per line.
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138       -v
139       --verbose
140           Enable verbose messages for debugging.
141
142       -V
143       --version
144           Display version number and exit.
145
146       -x  Enable tracing of libguestfs API calls.
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EXIT STATUS

149       This program returns 0 if successful, or non-zero if there was an
150       error.
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AUTHOR

157       Richard W.M. Jones http://people.redhat.com/~rjones/
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COPYRIGHT

160       Copyright (C) 2010-2023 Red Hat Inc.
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LICENSE

163       This program is free software; you can redistribute it and/or modify it
164       under the terms of the GNU General Public License as published by the
165       Free Software Foundation; either version 2 of the License, or (at your
166       option) any later version.
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168       This program is distributed in the hope that it will be useful, but
169       WITHOUT ANY WARRANTY; without even the implied warranty of
170       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
171       General Public License for more details.
172
173       You should have received a copy of the GNU General Public License along
174       with this program; if not, write to the Free Software Foundation, Inc.,
175       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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BUGS

178       To get a list of bugs against libguestfs, use this link:
179       https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
180
181       To report a new bug against libguestfs, use this link:
182       https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
183
184       When reporting a bug, please supply:
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186       •   The version of libguestfs.
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188       •   Where you got libguestfs (eg. which Linux distro, compiled from
189           source, etc)
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191       •   Describe the bug accurately and give a way to reproduce it.
192
193       •   Run libguestfs-test-tool(1) and paste the complete, unedited output
194           into the bug report.
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198guestfs-tools-1.51.6              2023-12-09                       virt-log(1)