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12

That entirely depends on what services you want to have on your device. Programs You can make Linux boot directly into a shell. It isn't very useful in production — who'd just want to have a shell sitting there — but it's useful as an intervention mechanism when you have an interactive bootloader: pass init=/bin/sh to the kernel command line. All Linux ...


8

Different modules behave differently when you provide the same option multiple times. I know you can say console= multiple times, and you get multiple consoles (we use it for machines with main consoles on both their framebuffers and serial port). However, you can only have one root partition, so root= almost certainly overwrites the previous value seen, ...


8

First of all the hassle with encrypted root and early userspace is typically already handled by your distribution (as far as i know Fedora, Debian, Ubuntu and OpenSUSE support encrypted root out of the box). That means you don't have to care for the setup itself. One reason for encrypting / is just to be sure you don't leak any information at all. Think ...


7

When the boot loader calls the kernel it passes it a parameter called root. So once the kernel finished initializing it will continue by mounting the given root partition to / and then calling /sbin/init (unless this has been overriden by other parameters). Then the init process starts the rest of the system by loading all services that are defined to be ...


7

/etc, /var, and /tmp come to mind. All can potentially have sensitive contents. All can be given separate volumes, but it's common for each of these to be on the same filesystem as the root directory. Maybe you've moved one or more off into their own volumes, but have you moved them all? /etc contains: hashed passwords; possibly multiple sorts, such as ...


6

It is given at boot time by your bootloader, for example Grub. To see with which arguments your kernel was started, do this: $ cat /proc/cmdline For me, this ouputs: BOOT_IMAGE=/vmlinuz-3.5.0-13-generic root=/dev/mapper/crypt-precise--root ro So the initrd/initramfs will try to mount my /dev/mapper/crypt-precise--root (encrypted LVM) logical volume as ...


5

Yes, it is a strong solution, but powerfull! Making r/o useable You have to mount some directories in rw, like /var, /etc and maybe /home. This could by done using aufs or unionfs. I like this another way, using /dev/shm and mount --bind: cp -a /var /dev/shm/ mount --bind /dev/shm/var /var You could before, move all directories who have not to change in ...


5

You should be able to log in as root, because usually a percentage of the partition's size is reserved in order to always enable root login for rescue operations and such. See this U&L Q&A: Reserved space for root on a filesystem - why? What you won't be able to do, however, is log in as a regular user from your display manager then switch to root ...


5

/tmp can be considered as a typical directory in most cases. You can recreate it, give it to root (chown root:root /tmp) and set 1777 permissions on it so that everyone can use it (chmod 1777 /tmp). This operation will be even more important if your /tmp is on a separate partition (which makes it a mount point). By the way, since many programs rely on ...


4

Linux provide many partitioning tools to re-size or shrink the partition that also without any data loss,It is possible to resize a partition using Gparted in a easy and a convenient way.As its a opensource and free download. To modify the partition with Gparted, it has to be downloaded then burned into a blank CD. This CD will be used as a bootable CD in ...


4

It's pretty straight forward, although we should distinguish between "driver" and "module". A driver may or may not be a module. If it is not, then it is built into the kernel loaded by the bootloader. If it is a module, then it is in a filesystem hierarchy rooted at /lib/modules/[kernel-release].1 Note that it is possible to boot a kernel together with ...


3

If you have free disk space (Partition, LVM) then you can mount it at /opt. If not then you can move /opt to e.g. /usr/opt and create a symlink in the rootfs. Or you make a bind mount (via fstab): mount --bind /usr/opt /opt


3

I usually make my root partition sizes for some of the distributions I run around 40 GB and haven't gone less than 20GB. It really depends on the operating system, display/window manager, and intended use. My intended use is Geographic Information Systems so this can involve installing several extra packages often exceeding several GBs (10+) in disk space ...


3

As the kernel documentation states, /dev/nfs is not a real device but only a hint to the kernel to use NFS as rootfs. You'll also have to tell the kernel where to find this root through the nfsroot parameter or a properly set up DHCP daemon. For the latter one to work you'll also have to either configure your kernel to auto-configure its network ...


3

The Archbang project don't have a central code repository, so it is difficult to establish what the current state is, however, it appears that there is an option in the Archbang ISO to bypass sections of the installer. This directory should have been removed in the script but, for whatever reason, in your case it failed to do that. You can remove the ...


3

/media/ is a stub where most modern distributions mount removable media when they are plugged in, e. g. USB hard drives, optical media, flash drives, etc. One of them you have mounted is identified as HDD2-200GB which is appearing as a 12.5GB filesystem, which is full. /mnt/ is another stub which is generally used for permanently mounted filesystems. ...


3

In my experience, no. The system will panic once the root device disappears. You can verify this in your particular situation if you want using a virtualization application like VirtualBox, qemu, kvm, etc. These will allow you to remove a virtual HDD from the machine and observe the result on the system. If you're interested in making a bootable USB drive ...


3

In Linux, most drivers can be either built statically into the kernel, or built as modules. This is a choice you can make when the kernel is being configured for compilation. They will only appear in /lib/modules/$(uname -r) if they are built as loadable modules. Typically, for general purpose systems, especially for pre-compiled kernels made available as ...


2

Check if you have kernels you aren't using. They can take up a lot of room, and Debian's automatic package management tends to leave old kernels behind. For example, if you're running kernel 2.6.32-5-686 (output of uname -r), you don't need linux-image-2.6.32-4-686 any more. For future reference, there's hardly any point nowadays in separating the /usr and ...


2

Ofcourse you should be worried but no need to panic since that you have seperate partitions for /var and /usr, that makes up for isolation of most often written and logged data which is good ; its important to have atleast some amount of free space (say 10% or 20% free space/reservation on all the filesystems) always around and you are not sure what ...


2

Make a backup before making any of the following changes Do not proceed without either a backup or the willingness to lose all data. run du -sh /home to get the size used by /home directory. If it's sufficiently large(>=4G), /home is a good candidate to have its own partition. Boot from either a livecd or SystemRescueCd Depending on your partition ...


2

You most likely moved the files at /*, which is essentially everything, given / is the top level directory and you move everything, *, under it. I guess my question would be where did you move it to? You might be able to move everything back if you can figure out where you moved it to. You'll have to call the mv command directly (ie. /accident/dir/mv) given ...


2

In case somebody has the same problem: All I needed was to move the mount point of the host file system to a place outside the root file system in the shutdown script (that's fine, because it runs in a tmpfs pivot root) before any unmounting takes place: mount --move /oldroot/run/initramfs/host /host This allows /oldroot to unmount cleanly. The host file ...


2

There is some linux trick to do this kind of work: mount --move which let you swap filesystem on mount point pivot_root which work with chroot for switch / root filesystem Initialy, the feature's goal was: booting kernel with an initramdisk as root filesystem (reserving some RAM for uncompressed initrd). All needed modules and scripts to access real ...


2

Yes, see for instance how to boot a VM with the FS of the host: Add the 9p modules to the host initramfs (that's the easiest way albeit not the cleanest, to have an initrd with the needed modules): printf '%s\n' 9p 9pnet 9pnet_virtio | sudo tee -a /etc/initramfs-tools/modules sudo update-initramfs -u qemu -kernel "/boot/vmlinuz-$(uname -r)" \ -initrd ...


2

All you need is one statically linked executable, placed on the filesystem, in isolation. You do not need any other files. That executable is the init process. It can be busybox. That gives you a shell and a host of other utilities, all in itself. You can go to a fully functioning system just by executing commands manually in busybox to mount the root ...


2

I can confirm that at least in Glibc, ld.so does follow symlinks when opening /etc/ld.so.cache. The code is in elf/dl-cache.c in the function _dl_load_cache_lookup, referencing the function _dl_sysdep_read_whole_file from elf/dl-misc.c. That function opens the file and maps it into memory; it doesn't do anything about symbolic links. Avoiding symbolic links ...


2

You can shred everything while it's mounted. Once you shred the contents of, say, /lib, you're not going to be able to do much else with the machine afterwards, but the existing shred process should be able to keep running no matter what you apply it to. Shredding /etc will stop you logging in again, but the basic tools should keep working in your current ...


2

In one word: yes :) How to do it is a different question. Try this in single user mode: mount -o ro,remount / Realize that some programs might not work (vim is the first thing that comes to mind).


1

The devices in /dev/bus/usb/XXX/YYY follow naming policies in the kernel as noted Gilles in the comments. XXX is the bus number which is quite stable, but YYY changes every time the USB device gets enumerated (when a device just got inserted or reset). This cannot be changed and you shouldn't have to change this either. If you need to change permissions on ...



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