General :: Use Initial RAM Disk As Root File System?
May 22, 2010
Information on the net seems very sparse or outdated for how to go about booting to a RAM disk. I need to be be able to boot a PC without a hard drive in it. I want to be able to PXE boot a PC and supply it with a RAM disk image that also contains the contents of the root file system (obviously stripped down enough to keep the file size small and the boot up time fast).What I have gathered so far is that I need to extract the contents of the initrd.img file, add files as necessary, and repackage the initrd.img file. What I get confused on is how to configure the kernel line parameters to tell it to boot to RAM and not the hard drive and how to go about modifying the init script in the initrd.img to not switch to the hard drive for the root file system. I can't find anything on the net that describes concrete steps on how to go about accomplishing all of this. I'm aware of the existence of Live CD's, but I need to be able to boot the PC without relying on a hard drive, CD, or any other external media. It needs to get all of its contents from the PXE boot server and boot to RAM only. I have the PXE boot side configured successfully. Also, putting the root file system on a NFS share is also out of the question.
I was trying to install Ubuntu desktop and laptop edition on a Sony Vaio netbook from a USB drive, but after I select the entire disk to be used and hit enter I get this message No root file system is defined. correct this from the partitioning menu. If I try to start windows I just get s black screen.
There isn't any separate file system for /home and we have only one (/) root file system for everything else on the system. Is there any way that we can still implement quotas for users through their home directories was mounted on (/) root file system. Do we need to have a separate file system (/home) compulsory for implementing disk quotas?
OS: Debian unstable 32bit, kernel 2.6.32-2, grub 1.98 from late january 2010 (only have working net-access from work now, so I am grabbing information from memory). EXT3 and EXT4 support is compiled into the kernel along with chipset/scsi/sata support (not as modules), and I have tested to boot ext3 with it before proceeding. Prereq: my old disk started to have too much S.M.A.R.T errors, so I bought another one, put in a USB cabinet, added swap and ext4 partition/filesystem to it, and copied over all data from the old system to the new that was mounted at /dest using the command "find ./ -xdev -print0 | cpio -paV0 /dest". Swiched disks, so I now have the ext4 disk sitting at /dev/sda (partitions: sda1 => ext4, sda2 => swap), and booted into rescue-mode from cdrom, using /dev/sda1 as root with a shell on. After doing this, I performed the following commands:
mount --bind /dev /dest/dev chroot /dest
modified the /etc/default/grub to instruct the kernel to boot using ext4, ran grub-install --recheck /dev/sda ran update-grub to modify /boot/grub/grub.cfg (which looks as it should) After doing this, grub finds my partition and mounts it. It however stalls with the message: "warning: unable to open an initial console" and does nothing after this point. I have no ramdisk, but my old kernel booted fine from ext3 (and still does if I copy it to a ext3 partition), and since the ext4 support is compiled into the kernel - should I really need a ramdisk?
I am fresh to Ubuntu and am having trouble getting it to boot on my system. I normally run XP, but recently added a second internal hard drive and installed Ubuntu on it. The installation went fine and upon initial reboot I received -
GRUB loading. error: no such disk grub rescue>
I am wondering if there is an issue between two different operating systems upon boot. I am not familiar with GRUB commands.
I work for a company that makes portable devices running Linux and I was recently asked to make the underlying file system read-only for "security" purposes. Since the distribution is based on LinuxFromScratch, I know that very little writing happens at run time. So, even if the device runs on a usb flash device, I doubt that putting the root file system RO will be that beneficial. I am actually more concerned about a process actually breaking because it cannot open a file in RW mode than a process going rogue and filling the root file system with log files, etc. I'd really like to ear what kind of advantages disadvantages there really is with read-only file-systems.
I messed up the first installation of Fedora on my server. My setup is as follows: Fedora and Gnome - NFS system, No dual boot (Windows or anything) Fedora ISO DVD downloaded No kickstart or other tools. how to set this up, from the time I insert the disk and have it boot up (configged already to boot from it). I know how to wipe it clean at intall time. Is that the root directory? And, is /boot the actual boot directory? I'm just having a hard time uderstanding that. As I said, I just want a quick itemized list, step 1, step 2, etc, from partitioning, creating file system, mounting, etc. in the right order.
I am getting an error while booting my linux system: Can't mount root file system.Boot has failed, sleeping forever.OS is Red hat enterprise linux 6, With Intel P4, 1 GB Ram, 120 GB IDE hdd seagate. it was working fine from last 4 days. from today morning this is giving error. only mysql & apache is installed in it. please suggest is there any way to repair the root & boot volumes. waiting for valuable reply.
Is it possible to encrypt the Entire root file system using LUKS.I am currently using Ubuntu 10.4 LUCID.After several hours of Google ,most of the articles were focusing to "Encrypting a drive/removable media ".. My aim is to encrypt whole File system which is currently using.
My Concerns, How to Encrypt a running file system? Will it lead to data loss?
im trying to prepare my partitions for fresh installation. The partition manager didnt list anything with an error message that said:Quote:No root file system is defined. Please correct this from the partitioning menu?This is what Gparted displays Quote:
I have been running Ubuntu as my sole OS for about a month now, and aside from Computer Janitor, I have found no drive/fs cleaning tools, or defragging tools. I know this isn't Windoze, but surely there must be a way of maintaining your hard disk. I mean installs/uninstalls must leave detritus, and file moving must cause SOME fragmentation. Are there any apps, systems or methods in place that provide this functionality?
I've been using *Unix systems for many years now, and I've always been led to believe that its best to partition certain dirs into separate FileSystems, off the main root FS.
For instance, /tmp /var /usr etc
Leaving as little as possible on the main / system.
Its so that you don't fill up the root system be accident, by some user putting in too bigger files in /tmp, for example.
I would presume that filling the / system would not be too good for Linux, as it would not be able to write logs and possibly other things that it needs to.
I believe that if root gets full, then there is something like a 5% amount saved for just 'root' to write to, so that it can do its stuff.
However, eventually, / will become full, and writes will fail.
On top of this, certain scripting tools, such as awk, use the /tmp/ system to store temp files in, and awk wont be able to write to /tmp/ as its full, so awk will fail.
However, I'm being advised that there is no need to put /tmp /var etc onto separate FSs, as there is no problem nowerdays with / filling up. So, /tmp /var /usr are all on the root FS.
I'm talking about large systems, with TBs of data (which is on a separate FS), and with a user populations of around 800-1000 users, and 24/7 system access.
I have a Rad Hat 7.0 old Linux system that crashed due to power failure. On reboot the system goes to Checking Root File System and does 92.5% check and fails.
Here are the error messages I get.
I don't know what to do at this point so I say yes and it goes in some wierd mode.
SO I ran fsck manually but I get an error PARALLEIZING FSCK.
I can't fix the corrupted stuff for the system to reboot. THIS IS VITAL.
I have a program that is very heavily hitting the file system, reading and writing randomly to a set of working files. The files total several gigabytes in size, but I can spare the RAM to keep them all mostly in memory. The machines this program runs on are typically Ubuntu Linux boxes.
Is there a way to configure the file system to have a very very large cache, and even to cache writes so they hit the disk later? I understand the issues with power loss or such, and am prepared to accept that. Crashing aside, in normal operation the writes should eventually reach the disk!Or is there a way to create a RAM disk that writes-through to real disk?
I need to customize linux kernel root file system for embedded linux system. During compile time, for root file system I am able to create different user/group ex: "gnumuzic/Muzic". But I want to give access to group "Muzic" to some folders like /dev/nexig during compile time.
standard Linux installation utilities split the root file-system and the home file-system on two separate but relatively equal-sized partitions? For example, when I put fedora on an 80GB disk, it automatically gave the root file-system 32GB and home 30GB and the swap 8GB of space. However, since my home file-system has a directory with 28GB of files in it, why is my root file-system reading 100% usage? Is the home FS overlaid on top of the root FS? Is there an advantage to doing this? I just made a boot partition (50mb or so), a root partition (90% of the disk space) and a swap (4%-5% disk space).
I am using Gentoo Linux and for a while now, the root file system is mounted read-only on booting. For obvious reasons, this is quite annoying as most services do not start up correctly (I do not use a separate file system for /var). After the system is up, I have to log in, remount the root file system read-write, fix /etc/mtab, mount all other file systems in from /etc/fstab and then start up all the missing daemons. I know that there are ways to make a system run properly with a read-only file system, but I would rather restore the old behaviour of a writable root file system.
The strange thing is that after running mount / -o remount,rw, the file system is mounted in writable mode without any errors. I suspected some problem with fsck, but now I have disabled automatic file system checks on the partition (tune2fs -c0 -i0).When I run dmesg, only these lines mention the partition at all, although I am not sure if not something gets lost because /var/log is not writable:
EXT3-fs (sda5): mounted filesystem with writeback data mode</code> EXT3-fs (sda5): using internal journal The line in /etc/fstab looks like this:
I have a fedora 14 system. I booted a suse installation that existed on an external harddisk and wanted to access my original fedora user home directory using non-root preveliges(so that i can use the gui file manager), so I searched on the internet and made a command to (chown -R mysuseUser:Users *) thinking that it will only affect the current mount permissions (not permenantly) put it did change the file system... i realized and cut it in the middle but some corruption was done. and then my fedora gui login screen was missing any username. tried to fix that by going to my fedora and executing chown (once using --from , and once without --from) and changed all root file system recursively to be owned by root and then changed my /home/myuserName ownerships all recursively to be owned by myUserName after that... still the system is corrupted..... when i login to genome i have several crash messages (gdiskutility is one of them) and networking is disabled (i cannot connect to neither wireless nor wired nor wireless broadband). also when i plug USB/esata harddisks nothing happens
now i can only do work from my external harddisk`s suse linux. what can i do to restore my system ? I have a previous dd image of my entire harddrive, but it is more than one month old and also I don`t want to do a restore to my entire harddrive.. can i clone some ownerships from files in dd image to their corresponding ones in my fedora system ? if so, how can i even mount a dd image ?
I'm running out of space in wubi. Online wubi help didn't help much since they suggest creating extra virtual disk space(similar to having a diffrent partition i guess) .None of them speak about increasing the size of /root disk space(or root.disk). I store all files in space shared with windows or external disk and use ubuntu only to install and use softwares and browsing. So how do increase the available space for installing more softwares?
I was using Ubuntu, installed over Wubi in WindowsXP. Due to some hard disk issues, I was having some problems booting into Windows. But Ubuntu was working fine. So i backed up all my data from Ubuntu and somehow managed to back up the 'root.disk' from Windows.That hard disk turned out to have some bad sectors. Now I am over a new hard disk with all my data and WindowsXP freshly installed. I want to have my old copy of Ubuntu back as I have the 'root.disk' file with me. How shall I proceed?I tried installing a fresh copy of Ubuntu using Wubi and then replace the 'root.disk' file. But it showed some Grub error.
I can use Ubuntu from my flash drive, but I want to install it in a partition alongside windows. When I try to do this, I come to an 'allocate drive space' window, but whatever I do I get the error message: 'No root file system is defined. Please correct this from the partitioning menu.' I just don't know what this means, or what to do next. I'm loathe to ditch windows, and I don't want to have to use a flashdrive all the time.
My system decided to crash on me, hard. It was humming along happily for about 2 months and now doesn't boot. If I boot from hard-disk, I get grub. Launching the first kernel choice hangs. I thought maybe the install was corrupt, so I booted from usb install disk. The usb hdd didn't boot; something about an error trying to access /dev/sda . Unplugging the internal disk and plugging in the usb install disk does result in the system booting. Plugging in the internal disk in a running system usb-booted system does not result in the system detecting the disk.
How do I know if the disk is physically broken? This seems unlikely since it does manage to launch grub consistently. Or is this still possible? How can I try to mount whatever is left? The usb install disk doesn't even list the /dev/sd*. Any pointers on how to reformat the drive if it's not being mounted?
In the boot process of Linux we have the initrd that is a root file system and is mounted before the real root file system become ready to mount. What is the procedure of mounting? What should happen so we can say that file system is mounted? And another little question why we say ¨root¨ file system instead of just file system?
I used mkinitrd to build an initrd from the slackware 2.6.37.6 sources. Lilo throws the following: "Warning: The initial RAM disk is too big to fit between the kernel a the 15M-16M memory hole. It will be loaded in the highest memory as though the configuration file specified "large-memory" and it will be assumed that the BIOS supports memory moves above 16M."
Also, I am running swap, / and home on an encrypted volume group. When the initrd boots (but prior to mounting the encrypted vg) I get a message saying that no modules are found-sounds like a daft question but is this expected? I expect that this is because initrd is looking for modules, but can't find them because the relevant partition isn't mounted.
I have windows and linux distros on my /dev/sda. I tried to install fedora 13, but after reboot I cannot boot up to any of installed systems. I'm getting: Non-System disk or disk errorreplace and striky any key when readyWhen I use ubuntu 10, boot from first hard disk, I'm able to get GNU GRUB version 1.98...nd boot up to any system. but without ubuntu in a cd-rom I'm getting this error.I tried: grub-install /dev/sdX in one of my installed linux distros, but without any success.
My linux distro is CentOS 5.3. Today I edited /etc/sysconfig/readonly-root and set "READONLY" to yes, now my /etc/sysconfig/readonly-root file is like this:
# Set to 'yes' to mount the system filesystems read-only. READONLY=yes # Set to 'yes' to mount various temporary state as either tmpfs
