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6 .TH LIVE\-BOOT 7 14.02.2013 4.0~a5\-1 "Debian Live Project"
9 \fBlive\-boot\fP \- System Boot Scripts
12 \fBlive\-boot\fP contains the scripts that configure a Debian Live system during
13 the boot process (early userspace).
16 live\-boot is a hook for the initramfs\-tools, used to generate a initramfs
17 capable to boot live systems, such as those created by
18 \fIlive\-helper\fP(7). This includes the Debian Live isos, netboot tarballs, and
22 At boot time it will look for a (read\-only) media containing a "/live"
23 directory where a root filesystems (often a compressed filesystem image like
24 squashfs) is stored. If found, it will create a writable environment, using
25 aufs, for Debian like systems to boot from.
28 \fBlive\-boot\fP can be configured through a boot parameter or a configuration
31 To configure the live\-boot parameters used by default in a live image, see
32 the \-\-bootappend\-live option in the \fIlb_config\fP(1) manual page.
34 .SS "Kernel Parameters"
35 \fBlive\-boot\fP is only activated if 'boot=live' was used as a kernel
38 In addition, there are some more boot parameters to influence the behaviour,
41 .SS "Configuration Files"
42 \fBlive\-boot\fP can be configured (but not activated) through configuration
43 files. Those files can be placed either in the root filesystem itself
44 (/etc/live/boot.conf, /etc/live/boot/*), or on the live media
45 (live/boot.conf, live/boot/*).
49 \fBlive\-boot\fP currently features the following parameters.
50 .IP \fBaccess\fP=\fIACCESS\fP 4
51 Set the accessibility level for physically or visually impaired
52 users. ACCESS must be one of v1, v2, v3, m1, or m2. v1=lesser visual
53 impairment, v2=moderate visual impairment, v3=blindness, m1=minor motor
54 difficulties, m2=moderate motor difficulties.
55 .IP \fBconsole\fP=\fITTY,SPEED\fP 4
56 Set the default console to be used with the "live\-getty" option. Example:
57 "console=ttyS0,115200"
59 Makes initramfs boot process more verbose.
63 Without setting debug to a value the messages may not be shown.
64 .IP \fBfetch\fP=\fIURL\fP 4
65 .IP \fBhttpfs\fP=\fIURL\fP 4
66 Another form of netboot by downloading a squashfs image from a given url.
67 The fetch method copies the image to ram and the httpfs method uses fuse and
68 httpfs2 to mount the image in place. Copying to ram requires more memory and
69 might take a long time for large images. However, it is more likely to work
70 correctly because it does not require networking afterwards and the system
71 operates faster once booted because it does not require to contact the
74 Due to current limitations in busybox's wget and DNS resolution, an URL can
75 not contain a hostname but an IP only.
77 Not working: http://example.com/path/to/your_filesystem.squashfs
79 Working: http://1.2.3.4/path/to/your_filesystem.squashfs
81 Also note that therefore it's currently not possible to fetch an image from
82 a namebased virtualhost of an httpd if it is sharing the ip with the main
85 You may also use the live iso image in place of the squashfs image.
86 .IP \fBiscsi\fP=\fIserver\-ip[,server\-port];target\-name\fP 4
87 Boot from an iSCSI target that has an iso or disk live image as one of its
88 LUNs. The specified target is searched for a LUN which looks like a live
89 media. If you use the \fBiscsitarget\fP software iSCSI target solution which is
90 packaged in Debian your ietd.conf might look like this:
92 # The target\-name you specify in the iscsi= parameter
95 Lun 0 Path=<path\-to\-your\-live\-image.iso>,Type=fileio,IOMode=ro
96 # If you want to boot multiple machines you might want to look at tuning some parameters like
97 # Wthreads or MaxConnections
98 .IP \fBfindiso\fP=\fI/PATH/TO/IMAGE\fP 4
99 Look for the specified ISO file on all disks where it usually looks for the
100 \&.squashfs file (so you don't have to know the device name as in
102 .IP \fBfromiso\fP=\fI/PATH/TO/IMAGE\fP 4
103 Allows to use a filesystem from within an iso image that's available on
105 .IP \fBignore_uuid\fP 4
106 Do not check that any UUID embedded in the initramfs matches the discovered
107 medium. live\-boot may be told to generate a UUID by setting
108 LIVE_GENERATE_UUID=1 when building the initramfs.
109 .IP \fBverify\-checksums\fP 4
110 If specified, an MD5 sum is calculated on the live media during boot and
111 compared to the value found in md5sum.txt found in the root directory of the
113 .IP "\fBip\fP=[\fIDEVICE\fP]:[\fICLIENT_IP\fP]:[\fINETMASK\fP]:[\fIGATEWAY_IP\fP]:[\fINAMESERVER\fP] [,[\fIDEVICE\fP]:[\fICLIENT_IP\fP]:[\fINETMASK\fP]:[\fIGATEWAY_IP\fP]:[\fINAMESERVER\fP]]" 4
114 Let you specify the name(s) and the options of the interface(s) that should
115 be configured at boot time. Do not specify this if you want to use dhcp
116 (default). It will be changed in a future release to mimick official kernel
117 boot param specification
118 (e.g. ip=10.0.0.1::10.0.0.254:255.255.255.0::eth0,:::::eth1:dhcp).
119 .IP \fBip\fP=[\fIfrommedia\fP] 4
120 If this variable is set, dhcp and static configuration are just skipped and
121 the system will use the (must be) media\-preconfigured
122 /etc/network/interfaces instead.
123 .IP {\fBlive\-media\fP|\fBbootfrom\fP}=\fIDEVICE\fP 4
124 If you specify one of this two equivalent forms, live\-boot will first try to
125 find this device for the "/live" directory where the read\-only root
126 filesystem should reside. If it did not find something usable, the normal
127 scan for block devices is performed.
129 Instead of specifing an actual device name, the keyword 'removable' can be
130 used to limit the search of acceptable live media to removable type
131 only. Note that if you want to further restrict the media to usb mass
132 storage only, you can use the 'removable\-usb' keyword.
133 .IP {\fBlive\-media\-encryption\fP|\fBencryption\fP}=\fITYPE\fP 4
134 live\-boot will mount the encrypted rootfs TYPE, asking the passphrase,
135 useful to build paranoid live systems :\-). TYPE supported so far are "aes"
136 for loop\-aes encryption type.
137 .IP \fBlive\-media\-offset\fP=\fIBYTES\fP 4
138 This way you could tell live\-boot that your image starts at offset BYTES in
139 the above specified or autodiscovered device, this could be useful to hide
140 the Debian Live iso or image inside another iso or image, to create "clean"
142 .IP \fBlive\-media\-path\fP=\fIPATH\fP 4
143 Sets the path to the live filesystem on the medium. By default, it is set to
144 \&'/live' and you should not change that unless you have customized your media
146 .IP \fBlive\-media\-timeout\fP=\fISECONDS\fP 4
147 Set the timeout in seconds for the device specified by "live\-media=" to
148 become ready before giving up.
149 .IP \fBmodule\fP=\fINAME\fP 4
150 Instead of using the default optional file "filesystem.module" (see below)
151 another file could be specified without the extension ".module"; it should
152 be placed on "/live" directory of the live medium.
153 .IP \fBnetboot\fP[=nfs|cifs] 4
154 This tells live\-boot to perform a network mount. The parameter "nfsroot="
155 (with optional "nfsopts="), should specify where is the location of the root
156 filesystem. With no args, will try cifs first, and if it fails nfs.
158 This lets you specify custom nfs options.
159 .IP \fBnofastboot\fP 4
160 This parameter disables the default disabling of filesystem checks in
161 /etc/fstab. If you have static filesystems on your harddisk and you want
162 them to be checked at boot time, use this parameter, otherwise they are
164 .IP \fBnopersistence\fP 4
165 disables the "persistence" feature, useful if the bootloader (like syslinux)
166 has been installed with persistence enabled.
168 Do not prompt to eject the live medium.
169 .IP \fBramdisk\-size\fP 4
170 This parameters allows to set a custom ramdisk size (it's the '\-o size'
171 option of tmpfs mount). By default, there is no ramdisk size set, so the
172 default of mount applies (currently 50% of available RAM). Note that this
173 option has no currently no effect when booting with toram.
175 This parameter enables usage of local swap partitions.
176 .IP \fBpersistence\fP 4
177 live\-boot will probe devices for persistence media. These can be partitions
178 (with the correct GPT name), filesystems (with the correct label) or image
179 files (with the correct file name). Overlays are labeled/named "persistence"
180 (see \fIpersistence.conf\fP(5)). Overlay image files have extensions which
181 determines their filesystem, e.g. "persistence.ext4".
182 .IP "\fBpersistence\-encryption\fP=\fITYPE1\fP,\fITYPE2\fP ... \fITYPEn\fP" 4
183 This option determines which types of encryption that we allow to be used
184 when probing devices for persistence media. If "none" is in the list, we
185 allow unencrypted media; if "luks" is in the list, we allow LUKS\-encrypted
186 media. Whenever a device containing encrypted media is probed the user will
187 be prompted for the passphrase. The default value is "none".
188 .IP \fBpersistence\-media\fP={\fIremovable\fP|\fIremovable\-usb\fP} 4
189 If you specify the keyword 'removable', live\-boot will try to find
190 persistence partitions on removable media only. Note that if you want to
191 further restrict the media to usb mass storage only, you can use the
192 \&'removable\-usb' keyword.
193 .IP "\fBpersistence\-method\fP=\fITYPE1\fP,\fITYPE2\fP ... \fITYPEn\fP" 4
194 This option determines which types of persistence media we allow. If
195 "overlay" is in the list, we consider overlays (i.e. "live\-rw" and
196 "home\-rw"). The default is "overlay".
197 .IP \fBpersistence\-path\fP=\fIPATH\fP 4
198 live\-boot will look for persistency files in the root directory of a
199 partition, with this parameter, the path can be configured so that you can
200 have multiple directories on the same partition to store persistency files.
201 .IP \fBpersistence\-read\-only\fP 4
202 Filesystem changes are not saved back to persistence media. In particular,
203 overlays and netboot NFS mounts are mounted read\-only.
204 .IP "\fBpersistence\-storage\fP=\fITYPE1\fP,\fITYPE2\fP ... \fITYPEn\fP" 4
205 This option determines which types of persistence storage to consider when
206 probing for persistence media. If "filesystem" is in the list, filesystems
207 with matching labels will be used; if "file" is in the list, all filesystems
208 will be probed for archives and image files with matching filenames. The
209 default is "file,filesystem".
210 .IP \fBpersistence\-label\fP=\fILABEL\fP 4
211 live\-boot will use the name "LABEL" instead of "persistence" when searching
212 for persistent storage. LABEL can be any valid filename, partition label, or
214 .IP \fBquickreboot\fP 4
215 This option causes live\-boot to reboot without attempting to eject the media
216 and without asking the user to remove the boot media.
217 .IP \fBshowmounts\fP 4
218 This parameter will make live\-boot to show on "/" the ro filesystems (mostly
219 compressed) on "/lib/live". This is not enabled by default because could
220 lead to problems by applications like "mono" which store binary paths on
223 If you boot with the normal quiet parameter, live\-boot hides most messages
224 of its own. When adding silent, it hides all.
225 .IP \fBtodisk\fP=\fIDEVICE\fP 4
226 Adding this parameter, live\-boot will try to copy the entire read\-only media
227 to the specified device before mounting the root filesystem. It probably
228 needs a lot of free space. Subsequent boots should then skip this step and
229 just specify the "live\-media=DEVICE" boot parameter with the same DEVICE
232 Adding this parameter, live\-boot will try to copy the whole read\-only media
233 to the computer's RAM before mounting the root filesystem. This could need a
234 lot of ram, according to the space used by the read\-only media.
235 .IP \fBunion\fP=aufs|unionfs 4
237 By default, live\-boot uses aufs. With this parameter, you can switch to
242 .IP \fB/etc/live.conf\fP 4
243 Some variables can be configured via this config file (inside the live
245 .IP \fBlive/filesystem.module\fP 4
247 This optional file (inside the live media) contains a list of white\-space or
248 carriage\-return\-separated file names corresponding to disk images in the
249 "/live" directory. If this file exists, only images listed here will be
250 merged into the root aufs, and they will be loaded in the order listed
251 here. The first entry in this file will be the "lowest" point in the aufs,
252 and the last file in this list will be on the "top" of the aufs, directly
253 below /overlay. Without this file, any images in the "/live" directory are
254 loaded in alphanumeric order.
257 .IP \fB/etc/live/boot.conf\fP 4
258 .IP \fB/etc/live/boot/*\fP 4
259 .IP \fBlive/boot.conf\fP 4
260 .IP \fBlive/boot/*\fP 4
261 .IP \fBpersistence.conf\fP 4
264 \fIpersistence.conf\fP(5)
268 \fIlive\-config\fP(7)
273 More information about live\-boot and the Debian Live project can be found on
274 the homepage at <\fIhttp://live.debian.net/\fP> and in the manual at
275 <\fIhttp://live.debian.net/manual/\fP>.
278 Bugs can be reported by submitting a bugreport for the live\-boot package in
279 the Debian Bug Tracking System at <\fIhttp://bugs.debian.org/\fP> or by
280 writing a mail to the Debian Live mailing list at
281 <\fIdebian\-live@lists.debian.org\fP>.
284 live\-boot was written by Daniel Baumann <\fIdaniel@debian.org\fP> for