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Booting SystemRescue

Boot from a removable device

To boot from a CD-ROM or USB device make sure that the computer firmware (BIOSor UEFI settings) is configured to boot the right device and that the priorityis correct.

To start SystemRescue, insert the CD or USB in the drive, and power on orreset your computer, or press a key to select an alternative boot device when itstarts.

Boot commandline options

In the bootloader you can press TAB (syslinux, used for classic BIOS boot) or“e” (grub, used for UEFI boot) to edit the boot commandline of the currentlyselected boot entry. You can then add the options listed below.

Available on commandline and YAML config

Most options are available on the boot commandline as well as in theYAML configuration in theglobal scope.Options on the boot commandline have higher priority than the ones in the YAML config.

The following options are supported on boot commandline and in YAML config:

setkmap=xx defines the system to configure the keyboard layout wherexxcorresponds to a keyboard map code. For examplesetkmap=de willconfigure the German keyboards layout during the boot process. You can alsoset the keyboard layout by running a command such assetkmap defrom the shell after boot time, and you can runsetkmap with no parameter inthe terminal on a running SystemRescue to get a list of all supported keymaps.
copytoram causes SystemRescue to be fully loaded into memory. Thiscorresponds to thedocache option in previous versions. A slower start butonce complete, the system will be more responsive and also it will not requirethe original device to run. It means you can actually work on the device whereSystemRescue is installed. This requires 2GB of memory to cache the system.
checksum will trigger a verification of the squashfs checksum during theboot so you know if the file has been corrupted. You should use this boot optionif you get unexpected errors when booting SystemRescue.
rootpass=password123: Sets the root password of the system running on thelivecd topassword123. That way you can connect from the network and ssh onthe livecd and authenticate using this password. For security reasons it isrecommended to use the alternativerootcryptpass option instead ofrootpassso the password is not visible as clear text.
rootcryptpass=xxxx: Sets the root password of the system running onthe livecd so you can connect to the system remotely via ssh and use thepassword to authenticate on the livecd. The password must be hashed usingthemkpasswd command. The mkpasswd program is available on most Linuxdistributions, it often comes as part of thewhois package.You need to provide the whole output of mkpasswd torootcryptpass=, includingthe$ prefix. The hashed password contains dollar signs so you should checkif your boot loader requires them to be escaped.If in doubt look at the/proc/cmdline of the booted SystemRescue.
nofirewall stop the iptables and ip6table services which are enabled bydefault in order to block incoming connection requests. You need to use thisoption if you need to establish connections to the system running SystemRescuefrom outside (for example connections to sshd). This option was introduced inSystemRescue-6.0.4.
rootshell=/bin/myshell use an alternative shell such as /bin/zsh insteadof /bin/bash. This option was introduced in SystemRescue-6.1.1.
cow_label=xxxx Set the filesystem label where upperdir/workdir files foroverlayfs must be stored. By default this option is not set and changes made onSystemRescue files are lost after a reboot. In other words you can use a Linuxfilesystem to persist all modifications made on SystemRescue when it runs suchas new bookmarks in Firefox, application configuration files, etc. You have toprovide the label of the filesystem that needs to be used to store thesechanges. All these changes will be isolated in a directory prefixed bypersistent unless you override this usingcow_directory
cow_directory=xxxx Name of the directory where to store changes made onthe system. You must have specified a cow device for this change to take effect.
loadsrm=y Load all SRM modules located on the boot device
noautologin Do not automatically login on the console. Use this option ifyou intend to use SystemRescue to run automatic jobs to connect remotely andwant to prevent local users from using the system from the console. This optionwas introduced in SystemRescue-8.06.
dostartx Automatically start the graphical environment. This optionwas introduced in SystemRescue-8.06.
dovnc Automatically start the VNC server to be able to remotely connectusing a graphical session. This option was introduced in SystemRescue-8.06.
vncpass=password123 Set the VNC password for connecting remotely. Withoutthis option connections to the VNC server will not be restricted. This optionwas introduced in SystemRescue-8.06.

Available only on commandline

The following options are supported only on the boot commandline:

cow_spacesize=xx sets the size of the Copy-on-Write area which is storedin a tmpfs file system in memory. It accepts values such as 512M, 4G and is setto 25% of the system memory by default.
nomodeset causes the system to run with a basic display driver in lowerresolution instead of using the most optimal display settings. Use this optionif information is not being displayed properly on the screen.
findroot: boot a Linux OS installed on disk using the SystemRescuekernel. This is very useful if you are unable to boot a Linux OS directly usingthe normal process. This could be caused by the boot loader being broken forexample. This option allows you to boot your system via SystemRescue so youcan fix the boot loader. This option works by scanning block devices during theboot process to find filesystems where a Linux operating system is installed(ie: filesystems which contain a file called/sbin/init). This includes blockdevices which are luks encrypted hence the user will have to provide thepassphrase in order to access these devices. It will then show a list of allblock devices which seems to be Linux root filesystems. The user will then needto choose the block device from which to boot. This option has been introducedin SystemRescue version 6.1.4.
break: stop the boot process before the root filesystem gets mounted. Ashell will be executed from the initramfs. This option allows to run commandsmanually in order to troubleshoot issues if SystemRescue cannot boot normally.
break=postmount: stop the boot process after the root filesystem getsmounted. A shell will be executed from the initramfs. This option allows to runcommands manually in order to troubleshoot issues if SystemRescue cannot bootnormally.
sysrescuecfg=filename.yaml adds additional yaml configuration filesto be loaded after the default ones in thesysrescue.d directory. This optioncan be specified one or multiple times on the boot command line. SeeYAML configuration for details.This option was introduced in SystemRescue-9.01.
archisolabel=xxxx Set the filesystem label where SystemRescue filesreside. In other words the system will try to find SystemRescue files on afilesystem having the label specified so it is important for it to locate onwhich device SystemRescue files are located. This is set toRESCUEXYZ bydefault since version 7.00 (it used to beSYSRCDXYZ with versions 6.x)where XYZ corresponds to the SystemRescue version (eg: the label isRESCUE803for version8.03)
archisobasedir=xxxx Set the base directory where all SystemRescue filesreside and it is set tosysresccd by default. In other words thesystem will try to find SystemRescue files in a directory namedsysresccd which is located at the root of the filesystem.
img_label=xxxx Set the filesystem label where SystemRescue ISO image islocated. This is only used when booting SystemRescue using the loopback optionfrom Grub2.
img_loop=xxxx Set the path to the SystemRescue ISO image within thefilesystem so the boot process can mount it and find the squashfs filesystem.This is only used when booting SystemRescue using the loopback option fromGrub2.
nomdlvm SystemRescue by default automatically activates all md RAID,device mapper and LVM devices that are found in the system. Activating themcan lead to writes to the disk and this is sometimes not wanted, for examplewhen doing forensics or working with defective disks. This option disablesthis behavior and all devices have to be activated manually.
archiso_http_srv= Set a HTTP URL (must end with /) where to downloadthe *.sfs file from when using HTTP. ${archisobasedir} and the architecture (x86_64)are added to the supplied URL.http and https are supported. When using https, no certificate check is done as theinitramfs environment doesn’t contain a trusted CA database.
archiso_nfs_srv= Set the NFS-IP:/path of the server where to downloadthe *.sfs file from when using NFS. ${archisobasedir} and the architecture (x86_64)are added to the supplied path. Note that due to tooling limitations only IPv4 addressesare supported, no DNS hostnames or IPv6.

Please readthe archiso documentationfor more advanced boot options and PXE boot in particular.

Options provided for autorun

These options are available on the boot commandline as well as in theYAML configuration in theautorun scope.

ar_source=xxx: place where the autorun are stored. It may be the rootdirectory of a partition (/dev/sda1),an nfs share (nfs://192.168.1.1:/path/to/scripts),a samba share (smb://192.168.1.1/path/to/scripts), oran http(s) directory (http://192.168.1.1/path/to/scripts).
ar_ignorefail: continue to execute the scripts chain even if a scriptfailed (returned a non-zero status)
ar_nodel: do not delete the temporary copy of the autorun scripts locatedin/var/autorun/tmp after execution
ar_disable: completely disable autorun, the simpleautorun script willnot be executed
ar_nowait: do not wait for a key press after the autorun script have beenexecuted.
ar_attempts: use this option if you want to retry to download the filemultiple times
ar_suffixes=[0-9]: comma separated list of suffixes corresponding to theautorun scripts to be run. For example withar_suffixes=0,2,7 the autorunscriptsautorun0,autorun2,autorun7 are going to be run, and scriptswith other suffixes will be ignored. Usear_suffixes=no to disable all theautorun scripts with a suffix.