From: Tails developers Date: Fri, 23 Mar 2012 11:38:48 +0000 (+0100) Subject: Update live-boot(7) man page and add new one for live.persist(5). X-Git-Tag: debian/3.0_a26-1~10 X-Git-Url: http://git.grml.org/?p=live-boot-grml.git;a=commitdiff_plain;h=72e4af787d6a44c35e97478a35a69b55cb33c191 Update live-boot(7) man page and add new one for live.persist(5). --- diff --git a/manpages/en/live-boot.7 b/manpages/en/live-boot.7 index ad6d1d2..65c9c31 100644 --- a/manpages/en/live-boot.7 +++ b/manpages/en/live-boot.7 @@ -1,4 +1,4 @@ -.TH LIVE\-BOOT 7 2012\-02\-06 3.0~a25-1 "Debian Live Project" +.TH LIVE\-BOOT 7 2012\-03\-23 3.0~a25-1 "Debian Live Project" .SH NAME \fBlive\-boot\fR \- System Boot Scripts @@ -107,7 +107,7 @@ This parameters allows to set a custom ramdisk size (it's the '\-o size' option .IP "\fBswapon\fR" 4 This parameter enables usage of local swap partitions. .IP "\fBpersistent\fR" 4 -live\-boot will probe filesystems for persistent media. These can either be the filesystems themselves, if labeled correctly, or image/archive files, if named correctly. Overlays are labeled/named either "live\-rw" or "home\-rw" and will be mounted on / or /home, respectively; snapshots are labeled/named either "live\-sn" or "home\-sn" and will be extracted into / or /home, respectively (see live\-snapshot(1) for more information). Overlays are mounted before snapshots are extracted, and for both overlays and snapshots, "live\-*" are handled before "home\-*". Overlay image files and snapshot archive files have extensions which determines their filesystem or archive type, e.g. "live\-rw.ext3" and "\home\-sn.squashfs". +live\-boot will probe devices for persistent media. These can be partitions (with the correct GPT name), filesystems (with the correct label) or image/archive files (with the correct file name). Overlays are labeled/named either "full\-ov", which will be mounted on /, or "custom\-ov", which can be completely customized (see \fIlive.persist\fR(5)); snapshots are labeled/named either "live\-sn" or "home\-sn" and will be extracted into / or /home, respectively (see \fIlive\-snapshot\fR(1) for more information). The order these are handled are: full\-ov, custom\-ov, live-sn, home-sn. Overlay image files and snapshot archive files have extensions which determines their filesystem or archive type, e.g. "custom\-ov.ext3" and "\home\-sn.squashfs". .IP "\fBpersistent\-encryption\fR=\fITYPE1\fR,\fITYPE2\fR ... \fITYPEn\fR" 4 This option determines which types of encryption that we allow to be used when probing devices for persistent media. If "none" is in the list, we allow unencrypted media; if "luks" is in the list, we allow LUKS\-encrypted media. Whenever a device containing encrypted media is probed the user will be prompted for the passphrase. The default value is "none". .IP "\fBpersistent\-media\fR={\fIremovable\fR|\fIremovable\-usb\fR}" 4 @@ -157,10 +157,13 @@ This saves expensive writes and speeds up operations on volatile data such as we .IP "\fB/etc/live/boot.d/\fR" 4 .IP "\fBlive/boot.conf\fR" 4 .IP "\fBlive/boot.d/\fR" 4 +.IP "\fBlive.persist\fR" 4 .SH SEE ALSO \fIlive\-snapshot\fR(1) .PP +\fIlive.persist\fR(5) +.PP \fIlive\-build\fR(7) .PP \fIlive\-config\fR(7) diff --git a/manpages/en/live.persist.5 b/manpages/en/live.persist.5 new file mode 100644 index 0000000..eff56da --- /dev/null +++ b/manpages/en/live.persist.5 @@ -0,0 +1,211 @@ +.TH LIVE.PERSIST 5 2012\-03\-23 3.0~a25-1 "Debian Live Project" + +.SH NAME +\fBlive.persist\fR \- Configuration file for persistent media in +live\-boot + +.SH DESCRIPTION +If live-boot probes a persistent volume with the label (or GPT name, +or file name, but from now on we will just say "label") "custom\-ov", +that volume's persistence is fully customizable through the +\fBlive.persist\fR file stored on the root of its file system. Any such +labeled volume must have such a file, or it will be ignored. +.PP +The format of \fBlive.persist\fR allow empty lines and lines starting +with a "#" (used for comments), both which will be ignored. A so +called "custom mount" has the format: +.PP +.RS +\fIDIR\fR [\fIOPTION\fR]... +.RE +.PP +which roughly translates to "make \fIDIR\fR persistent in the way +described by the list of \fIOPTION\fRs". +.PP +For each custom mount \fIDIR\fR must be an absolute path that cannot +contain white spaces or the special . and .. path components, and +cannot be /live (or any of its sub-directories), or / (for the latter, +use "full-ov" persistence instead). Once activated all changes (file +deletion, creation and modification) to \fIDIR\fR on the live file +system are stored persistently into a path equivalent to \fIDIR\fR on +the persistent media, called the source directory. The default way to +achieve persistence is to simply bind-mount the corresponding source +directory to \fIDIR\fR, but this can be changed through the use of +\fIOPTION\fRs. +.PP +All custom mounts will be done in an order so that no two custom +mounts can "hide" each other. For instance, if we have the two +\fIDIR\fR:s /a and /a/b it would always be the case that /a is mounted +first, then /a/b. This remains true no matter how the lines in +\fBlive.persist\fR are ordered, or if several \fBlive.persist\fR files +on different persistent media are used at the same time. However, it +is forbidden for custom mounts to have their source directory inside +the source directory of another custom mount, so the source +directories that are auto-created by live-boot does not support +"nested" mounts like /a and /a/b on the same media. In this case you +must use the \fBsource\fR option (see below) to make sure that they +are stored in different source directories. +.PP +When a source directory doesn't exist on the persistent media for a +certain custom mount, it will be created automatically, and +permissions and ownership will be optimistically set according to +\fIDIR\fR. It will also be bootstrapped by copying the contents of the +\fIDIR\fR into its source directory on the persistent media. The +bootstrapping will not happen when the \fBlinkfiles\fR or \fBunion\fR +options are used (see below). + +.SH OPTIONS +Custom mounts defined in \fBlive.persist\fR accept the following +options in a coma-separated list: +.IP "\fBsource\fR=\fIPATH\fR" 4 +When given, store the persistent changes into \fIPATH\fR on the +persistent media. \fIPATH\fR must be a relative path (w.r.t. the +persistent media root) that cannot contain white spaces or the +special . or .. path components, with the exception that it can be +just . which means the persistent media root. This option is mostly +relevant if you want to nest custom mounts, which otherwise would +cause errors, or if you want to make the whole media root available +(similar to the now deprecated \fBhome-rw\fR type of persistence). +.PP +The following options will override the default bind-mount behaviour +of custom mounts, and are mutually exclusive: +.IP "\fBlinkfiles\fR" 4 +Create the directory structure of the source directory on the +persistent media in \fIDIR\fR and create symbolic links from the +corresponding place in \fIDIR\fR to each file in the source directory. +Existing files or directories with the same name as any link will be +overwritten. Note that deleting the links in \fIDIR\fR will only +remove the link, not the corresponding file in the source; removed +links will reappear after a reboot. To permanently add or delete a +file one must do so directly in the source directory. +.IP +Effectively \fBlinkfiles\fR will make only files already in the source +directory persistent, not any other files in \fIDIR\fR. These files +must be manually added to the source directory to make use of this +option, and they will appear in \fIDIR\fR in addition to files already +there. This option is useful when only certain files need to be +persistent, not the whole directory they're in, e.g. some +configuration files in a user's home directory. +.IP "\fBunion\fR" 4 +Save the rw branch of a union on the persistent media, so only the +changes are stored persistently. This can potentially reduce disk +usage compared to bind-mounts, and will not hide files added to the +read-only media. One caveat is that the union will use \fIDIR\fR from +the image's read-only file system, not the real file system root, so +files created after boot (e.g. by live-config) will not appear in the +union. This option will use the union file system specified by +live-boot's \fBunion\fR boot parameter, but is not supported with +\fBunion=unionmount\fR. + +.SH DIRECTORIES +.IP "\fB/live/persistent\fR" 4 +All persistent volumes will be mounted here (in a directory +corresponding to the device name). The \fBlive.persist\fR file can +easily be edited through this mount, as well as any source directories +(which is especially practical for custom mounts using the +\fBlinkfiles\fR option). + +.SH EXAMPLES + +Let's say we have a persistent volume \fIVOL\fR with the a +\fBlive.persist\fR file containing the following four lines (numbered +for ease of reference): +.TP 7 +1. +/home/user1 linkfiles,source=config-files/user1 +.TP +2. +/home/user2 linkfiles,source=config-files/user2 +.TP +3. +/home +.TP +4. +/usr union +.PP +The corresponding source directories are: +.TP 7 +1. +\fIVOL\fR/config-files/user1 (but it would be \fIVOL\fR/home/user1 +without the \fBsource\fR option) +.TP +2. +\fIVOL\fR/config-files/user2 (but it would be \fIVOL\fR/home/user2 +without the \fBsource\fR option) +.TP +3. +\fIVOL\fR/home +.TP +4. +\fIVOL\fR/usr +.PP +It was necessary to set the \fBsource\fR options for 1 and 2, since +they otherwise would become nested with 3's source, which is illegal. +.PP +Line 3 will be taken care of before line 1 and 2 in order to prevent +custom mounts 1 and 2 from being hidden by 3. When line 3 is handled, +\fIVOL\fR/home is simply bind-mounted on /home. To illustrate what +happens for lines 1 and 2, let's say that the following files exist: +.TP 7 +a. +\fIVOL\fR/config-files/user1/.emacs +.TP +b. +\fIVOL\fR/config-files/user2/.bashrc +.TP +c. +\fIVOL\fR/config-files/user2/.ssh/config +.PP +Then the following links and directories will be created: +.TP 7 +Link: +/home/user1/.emacs -> \fIVOL\fR/config-files/user1/.emacs (from a) +.TP +Link: +/home/user2/.bashrc -> \fIVOL\fR/config-files/user2/.bashrc (from b) +.TP +Dir: +/homea/user2/.ssh (from c) +.TP +Link: +/home/user2/.ssh/config -> \fIVOL\fR/config-files/user2/.ssh/config +(from c) +.PP +One could argue, though, that lines 1 and 2 in the example +\fBlive.persist\fR file above are unnecessary since line 3 already +would make all of /home persistent. The \fBlinkfiles\fR option is +intended for situations where you don't want a complete directory to +be persistent, only certain files in it or its sub-directories. +.PP +Line 4 can be mounted at any time since its \fIDIR\fR (and source +directory) is completely disjoint from all the other custom +mounts. When mounted, \fIVOL\fR/usr will be the rw branch due to the +\fBunion\fR option, and will only contain the difference compared to +the underlying read-only file system. Hence packages could be +installed into /usr with great space-wise efficiency compared to +bind-mounts, since in the latter case all of /usr would have to be +copied into \fIVOL\fR/usr during the initial bootstrap. + +.SH SEE ALSO +\fIlive\-boot\fR(7) +.PP +\fIlive\-build\fR(7) +.PP +\fIlive\-config\fR(7) +.PP +\fIlive\-tools\fR(7) + +.SH HOMEPAGE +More information about live\-boot and the Debian Live project can be +found on the homepage at <\fIhttp://live.debian.net/\fR> and in the +manual at <\fIhttp://live.debian.net/manual/\fR>. + +.SH BUGS +Bugs can be reported by submitting a bugreport for the live\-boot +package in the Debian Bug Tracking System at +<\fIhttp://bugs.debian.org/\fR> or by writing a mail to the Debian +Live mailing list at <\fIdebian-live@lists.debian.org\fR>. + +.SH AUTHOR +live\-boot was written by anonym <\fIanonym@lavabit.com\fR> for the +Debian project.