1GRUBBY(8)                   System Manager's Manual                  GRUBBY(8)
2
3
4

NAME

6       grubby - command line tool for configuring grub and zipl
7
8

SYNOPSIS

10       grubby [--add-kernel=kernel-path] [--args=args]
11              [--bad-image-okay] [--config-file=path] [--copy-default]
12              [--default-kernel] [--default-index] [--default-title]
13              [--env=path] [--grub2] [--info=kernel-path]
14              [--initrd=initrd-path] [--extra-initrd=initrd-path]
15              [--make-default] [--remove-args=args]
16              [--remove-kernel=kernel-path] [--set-default=kernel-path]
17              [--set-default-index=entry-index] [--title=ntry-title]
18              [--update-kernel=kernel-path] [--zipl] [--bls-directory=path]
19
20

DESCRIPTION

22       grubby  is  a command line tool for updating and displaying information
23       about the configuration files for the grub2 and zipl boot loaders.   It
24       is primarily designed to be used from scripts which install new kernels
25       and need to find information about the current boot environment.
26
27       On BIOS-based Intel x86 platforms, grub2 is the default bootloader  and
28       the  configuration file is in /boot/grub2/grub.cfg. On UEFI-based Intel
29       x86 platforms, grub2 is the default bootloader, and  the  configuration
30       file is in /boot/efi/EFI/redhat/grub.cfg. On PowerPC platforms, systems
31       based on Power8 and Power9 support grub2 as a bootloader and use a con‐
32       figuration  stored in /boot/grub2/grub.cfg. On s390x platforms the zipl
33       bootloader use a default configuration in /etc/zipl.conf.
34
35       All bootloaders define the boot  entries  as  individual  configuration
36       fragments  that are stored by default in /boot/loader/entries. The for‐
37       mat   for   the   config   files   is   specified    at    https://sys
38       temd.io/BOOT_LOADER_SPECIFICATION.   The  grubby tool is used to update
39       and display the configuration defined in  the  BootLoaderSpec  fragment
40       files.
41
42       There  are  a  number  of  ways  to specify the kernel used for --info,
43       --remove-kernel,  and  --update-kernel.  Specificying  DEFAULT  or  ALL
44       selects  the default entry and all of the entries, respectively.  Also,
45       the title of a boot entry may be specified by using TITLE=title as  the
46       argument; all entries with that title are used.
47
48

OPTIONS

50       --add-kernel=kernel-path
51              Add a new boot entry for the kernel located at kernel-path.
52
53
54       --args=kernel-args
55              When  a  new  kernel  is  added, this specifies the command line
56              arguments which should be passed to the kernel by default  (note
57              they  are  merged  with  the  arguments  of the default entry if
58              --copy-default is used).  When  --update-kernel  is  used,  this
59              specifies  new  arguments to add to the argument list. Multiple,
60              space separated arguments may be used. If  an  argument  already
61              exists  the  new value replaces the old values. The root= kernel
62              argument gets special handling if  the  configuration  file  has
63              special handling for specifying the root filesystem.
64
65
66       --bad-image-okay
67              When  grubby  is looking for an entry to use for something (such
68              as a default boot entry) it uses sanity checks, such as ensuring
69              that  the  kernel exists in the filesystem, to make sure entries
70              that obviously won't work aren't selected. This option overrides
71              that behavior, and is designed primarily for testing.
72
73
74       --config-file=path
75              Use path as the configuration file rather then the default.
76
77
78       --copy-default
79              grubby  will  copy as much information (such as kernel arguments
80              and root device) as possible from the  current  default  kernel.
81              The kernel path and initrd path will never be copied.
82
83
84       --default-kernel
85              Display the full path to the current default kernel and exit.
86
87
88       --default-index
89              Display  the numeric index of the current default boot entry and
90              exit.
91
92
93       --default-title
94              Display the title of the current default boot entry and exit.
95
96
97       --env=path
98              Use path as the grub2 environment block  file  rather  then  the
99              default path.
100
101
102       --grub2
103              Configure grub2 bootloader.
104
105
106       --info=kernel-path
107              Display information on all boot entries which match kernel-path.
108              If kernel-path is DEFAULT, then information on the default  ker‐
109              nel is displayed. If kernel-path is ALL, then information on all
110              boot entries are displayed.
111
112
113       --initrd=initrd-path
114              Use initrd-path as the path to an initial ram  disk  for  a  new
115              kernel being added.
116
117
118       --extrainitrd=initrd-path
119              Use  initrd-path as the path to an auxiliary init ram disk image
120              to be added to the boot entry.
121
122
123       --make-default
124              Make the new kernel entry being added the default entry.
125
126
127       --remove-args=kernel-args
128              The arguments specified by kernel-args are removed from the ker‐
129              nels  specified  by --update-kernel. The root argument gets spe‐
130              cial handling for configuration files that support separate root
131              filesystem configuration.
132
133
134       --remove-kernel=kernel-path
135              Removes  all  boot  entries which match kernel-path. This may be
136              used along with --add-kernel, in which case the new kernel being
137              added will never be removed.
138
139
140       --set-default=kernel-path
141              The  first  entry  which  boots the specified kernel is made the
142              default boot entry.
143
144
145       --set-default-index=entry-index
146              Makes the given entry number the default boot entry.
147
148
149       --title=entry-title
150              When a new kernel entry is added  entry-title  is  used  as  the
151              title for the entry.
152
153
154       --update-kernel=kernel-path
155              The  entries  for kernels matching kernel-path are updated. Cur‐
156              rently the only items that can be updated is the kernel argument
157              list,  which  is  modified  via  the  --args  and  --remove-args
158              options. If the ALL argument is  used  the  variable   GRUB_CMD‐
159              LINE_LINUX  in /etc/default/grub is updated with the latest ker‐
160              nel argument list, unless  the  --no-etc-grub-update  option  is
161              used.
162
163
164       --zipl Configure zipl bootloader.
165
166
167       --bls-directory=path
168              Use  path  as  the directory for the BootLoaderSpec config files
169              rather than the default /boot/loader/entries.
170
171
172       --no-etc-grub-update
173              Makes grubby to not update the  GRUB_CMDLINE_LINUX  variable  in
174              /etc/default/grub  when  the --update-kernel option is used with
175              the ALL argument.
176
177

SEE ALSO

179       zipl(8), mkinitrd(8), kernel-install(8)
180
181

AUTHORS

183       Erik Troan
184       Jeremy Katz
185       Peter Jones
186       Javier Martinez
187
188
189
190                                Wed Apr 29 2020                      GRUBBY(8)
Impressum