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
[code]...
2 days ago I had installed Fedora 9 on an old machine. The installation was from a Flash USB, and was OK and the kernel on thar installation was 2.6.25-14.fc9.i686.
After the installation I updated the system, and all looks to be ok, and the system was set with the kernel 2.6.27.25-78.2.56.fc9.i686.
But when I start the system with the latest kernel itś get blockd on "remounting root filesystem in read-write mode" step, but not with the original kernel witch start correctly.
I need to change a filename but when I boot up I get the message root device is read-only. Is there a way of changing this so that I can change the filename. I have a Mac Pro running Leopard OSX. The graphics card an NVIDIA 7500GT or driver has failed. It was suggested elsewhere that I change the relevant kext files to filename.kext.old, which I did, now when I try to boot start in OSX I get a message in various languages telling me to restart. I have tried booting in safe mode and from original Installation CD. In Safe Mode I get the same multi language splash screen, from CD I still have the graphic card problem, screen freezes and artifacts appear. So I boot up straight into CLI by holding down CMD-S hoping to be able to change filenames back but it says device read-only.
View 2 Replies View RelatedI need to allow non-root users to read/write on an ext3 partition.
Below is the relevant output from fdisk -l
Code:
The partition in question is /dev/sda4 and it is mounted as /Data (setup during installation).
i was using ubuntu 9.04 . i had changed fstab mount option of my ubuntu partition from exec,utf8 to executf8.now i cant get the gui of my ubuntu . only command line appears and i cant edit fstab even from root. it says that the filesystem is readonly.i tried mount -o remount,rwit does'nt work.if anyone have a methode other than reinstall my ubuntu.
View 3 Replies View RelatedI'm running CentOS 4.3 on a VM which is an application server for Quinstreet. trouble is when i keep coming in during the mornings it seems to keep making this root filesystem read only. There is no pattern for this and neither is it clear in the messages log why this keeps happening.
View 5 Replies View RelatedDebugging some of my scripts after upgrading from Debian Lenny to Ubuntu 10.04. In so doing, I tripped over this "problem," the solution to which may give me a clue to others.
On a bash shell command line I created a file thusly:
sudo touch zero_file
and it lists as expected with default permissions 0644:
-rw-r--r-- 1 root root 0 2011-03-09 11:18 zero_file
But then this command fails
sudo echo abcdef >>zero_file
-bash: zero_file: Permission denied
I can place the command (minus the "sudo") in a script & run it under the auspices of sudo & it works. Am I missing something re the stdin redirection when using sudo?
Remember back in the days of MS-DOS, a file could have 4 different attributes: archive, read-only, hidden, system. As you know, MS-DOS didn't have any user rights or privileges. Files had no owner. If you were at the command line, you could do whatever you wanted, you could change or delete any files you wanted to... so long as they weren't read-only. Under MS-DOS, if you had a read-only file and tried to delete it, you would get an error saying "Cannot delete read-only file". There was a simple remedy to this, just turn off the read-onlyness:
Code:
attrib -r hello.txt
The point I'm trying to make here is that even though you had full permissions over the file, you still had to turn off its read-onlyness before you could make a change. Well I'm trying to do something similar in Linux. Under Linux, the root user has full permissions over every file. But I need to make a particular file read-only so that not even the root user can alter it. I have a few programs on my computer that need to be run as root because they do some low-level networking (raw sockets and the like), and these programs alter my "/etc/resolv.conf" file. Well I need to find a way of making my "/etc/resolv.conf" file READ-ONLY, even for the root user. It doesn't seem as though the Linux filesystem provides a means of doing this, reason being that the root user will always be able to alter any file it wants to. I was thinking though... there's some way I could turn my "/etc/resolv.conf" file into a virtual file of some sort, like maybe I could use some sort of mount program to mount the file as read-only... ?
I have a Windows 2003 server with fiber attached volumes (NTFS) that I would like to mount readonly on a linux system to back it up to tape. The fiber device will allow me to present the volume R/W to one host and R/O to another, however, the R/O system doesn't see any of the changes made by the R/W server. In other words, how can I make a readonly volume refresh, scan for changes, or update without un/re-mounting it?
Is the "mount -o --bind" option what I want? From the MAN is doesn't seem right... the option "sync" seems slightly more promising but I think I'm just grasping at straws here. The best I have come up with is a cron job to unmount then mount the volume periodically.
I just noticed on my Ubuntu machine (ext3 filesystem) that removing write permissions from a file does not keep root from writing to it. Is this a general rule of UNIX file permissions? Or specific to Ubuntu? Or a misconfiguration on my machine? Writing to the file fails (as expected) if I do this from my normal user account.Is this normal behavior?Is there a way to prevent root from accidentally writing to a file (Preferably using normal filesystem mechanisms, not AppArmor, etc.)
I understand that root has total control over the system and can, eg, change the permissions on any file.My question is whether currently set permissions are enforced on code running as root. The idea is the root user preventing her/himself from accidentally writing to a file. also understand that one should not be logged in as root for normal operations.
I'm setting up Ubuntu Karmic on my sister's old computer for my nephew, he's quite young so my sister asked to install some content filtering. I'll first setup an OpenDNS account and I've installed and managed to get dansguardian and squid working on a virtual machine to try it out. so far it's working pretty well, but I need to secure it form the inside out.
I was thinking of blocking specific outbound ports so he could not bypass the proxy. because by default the firefox configuration can be easily changed. so I have a couple of questions.
1. is it possible to block outgoing ports on Ubuntu?
2. is that the best method?
3. is there anything else I should be aware of to prevent subversion?
lastly, this question is probably unrelated to this board but I've set up a cron job to update a dynamic ip with OpenDNS, the problem is that the password is in clear text in the user's crontab, can I play with permissions? is it possible to run the job under a root account and deny read/write access to a normal user?
After an error on my root fs it had been remountet readonly. sudo mount -n -o remount, rw /
Can't open /var/lib/sudo/martin/0: Read-only file system mount: you must specify the filesystem type
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:
[code]....
I have been given a headless linux system running from a SD card. I get into it by putty, directly to root, not other user and even /home dir. Whatever I copy or write will dissapear because is ro.
my etc/fstab file is:
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
/dev/hda1 /boot vfatnoauto,rw 0 0
What are the possible problem when Windows access the file from Ubuntu got Read Only even though have a full permission to read, write and execute the file? Ubuntu to Ubuntu accessing the file there is no problem only Windows got a problem.
View 1 Replies View RelatedI was just copying a large (50GB) file from one mounted partition to another mounted partition (a USB drive), but before the operation completed, my root filesystem, on a separate partition, filled up.Because it filled up I also couldn't get past the login when I rebooted. I think this is because there is no room to load temporary files. I'm expanding the root partition to temporarily fix this. how can I avoid my root file system filling up when copying a massive file between mounted partitions? the file is being cached in root during the transfer.
View 3 Replies View RelatedI am running Ubuntu Linux 10.04.1 on an AMD 64-bit system. The server is primarily used for Windows file sharing via Samba in a small local network. I use webmin and putty to administer the system. I have two 1.4 TB drives for storage and one 500 GB drive with 18 GB mounted for root.I performed a large cut & paste operation (25.8 GB of files) using the File Manager in Webmin to move a certain folder into another folder within /media/Work. The operation failed and I am now getting a "root filesystem full" error, and am stumped.
View 8 Replies View RelatedI have a Linksys WRT54G with the Tomato firmware on it. So the system running on the router is Busybox 1.14., which as far as I know is Linux-based. I want to update the busybox to the newest version, using ipkg which is the only package manager it has installed on it. By the way, I use telnet to access the router. So I use # ipkg install (the url to newest busybox release) but at some point it stops and says:
mkdir: cannot create directory '//opt/usr/': Read-only file system
so what can I do? How can I make the filesystem read-write?
I am interested in making the root file system is read-only. I've moved /var and /tmp file systems to another partitions. There are two files in the /etc directory that need to be writable.
These are:
I've moved this files to /var and linked it. I've added command to the /etc/rc.d/rc.local file:
That's it. Are there other solutions to make the root file system is read-only?
I came across this issue today and it changes everything I know about file permissions in linux. I created the following files in my system :
Code:
/tmp> ls -lad /tmp/testperm/
drwx------ 2 sagi users 4096 Apr 12 20:23 /tmp/testperm/
/tmp> ls -lad /tmp/testperm/file.txt
-rw------- 1 sagi users 12 Apr 12 20:23 /tmp/testperm/file.txt
[code]....
One more thing, as you can see I also set that only the owner of the directory (which is me again) can read and cd (the execute bit) to the directory. how come user 'root' can read the content of the file ?
Code:
# id
uid=0(root) gid=0(root) groups=0(root)
# cat /tmp/testperm/file.txt
Hello world
[code]....
I have a 9.04 64bit Ubuntu server that I use for a home file server and for downloading duties, every few days the root filesystem gets remounted as read only, usually requiring a reboot and fsck to get everything running again. The box is tucked away in the roof space to keep the noise down so it's a bit of a pain to keep pulling it out to get console access.troubleshoot what might be causing this?/ is on a raid 1 array on 2 8GB usb sticks last few lines of DMESG EXT3-fs error (device md3): ext3_journal_start_sb: Detected aborted journal
Code:
[632280.290419] journal_bmap: journal block not found at offset 23180 on md3
[632280.290470] Aborting journal on device md3.
[code]....
For my project, it's absolutely necessary to have a read-only root partition system. I have a writable /opt/project partition.But, I also need to start x server. startx This tries to write to some temporary files and fails as / is readonly. Is there any how-to on how to move this temporary files to the writable portions of the file system.
View 3 Replies View RelatedWhen I try to boot to OpenSUSE I get the following error during boot-up: unknown filesystem type 'reiserfs' could not mount root filesystem - exiting to /bin/sh$
This only started happening quite recently - before this I could boot to Linux quite happily.
I am using GRUB bootloader. I can boot into windows fine. But booting into linux gives me the error "kernel panic: unable to mount root fs on unknown block(0,0)I got LILO to load linux fine but GRUB always gives me this error regardless of the linux OS for this particular computer.
View 11 Replies View RelatedI boot up a Linux appliance entirely in RAM, ie. the image has a Linux kernel and an attached ext2 root filesystem.
Now that it's working, I would like to copy the root filesystem from RAM to a NAND flash memory.
Can I just mount the NAND, run "cp -a /* /mnt/nand", reboot with the kernel command line "root=/dev/mtdblock2 rw", and expect Linux to be happy... or is it more involved than this?
Suppose I have a good backup of the / root filesystem. How do I recover the / root area? Suppose I have modified the root filesystem, perhaps I do an update some of the packages and regret it, and I want to get back to the system at the time of the backup. How do most linux people recover the root area of a system from a backup?
1) I wondered if I might put a System Rescue CD in and boot off it?
2) And then NFS mount the directory containing the backup? -In my case, I have made a good backup using rsync, to a directory elsewhere on the network.
3) And then, still booted off the System Rescue CD, mount the partition that contains the / root area in question?
4) Would I then clear or empty or delete the contents from the / root partition?
5) And then copy across all the files from the backup into the / root partition?
I ask these questions because of the (very nice) way linux OS is built entirely from packages... Am I being too complicated? (By comparison, I can see it is easy to recover user data.)If, instead, I simply recovered the backup straight onto the updated root filesystem, I wonder what it would look like if I then tried to verify it with "rpm -Va", for example? Surely, all the packages would fail the verification, because it would think it has a later version of each package from the update, but the actual files would have been overwritten by the earlier version from the backup?
When i installed ubuntu. I made a seperate partition so that i could copy an ISO image onto it of an up-to-date version of ubuntu. I wanted to then boot the ISO up so i could install the new version that way. I've already tried doing it through the update manager but it'll download, almost be done with installing and it freezes on me. so i figured this would be easier. However i do not know how to gain access to the other partition to copy the ISO image. Please help.
View 1 Replies View RelatedI have just tried to update my kernel from 2.6.24.5 to 2.6.39-rc3 on a Slackware 12.1 distribution. I have successfully updated the kernel before, but it was from a newer distribution and newer kernel(Slackware 13.1 and 2.6.33.4). After I updated and rebooted, I got the following error:
Code:
List of all partitions:
0300 4194302 hda driver: ide-cdrom
0800 312571224 sda driver: sd
0801 244197560 sda1 00000000-0000-0000-0000-000000000sda1
0802 68372640 sda2 00000000-0000-0000-0000-000000000sda2
No filesystem could mount root, tried: romfs
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block (8,1)
Pid: 1, comm: swapper Not tainted 2.6.39-rc3-smp #1 .....
I'm trying to boot Emdebian Grip 1.0 built on Compact Flash on a mini PC with grub2 as bootloader. Unfortunately , the booting is unsuccessful and I got stuck into an error message :Code:No filesystem could mount root , tried : minix msdos iso9660kernel panic - not syncing : VFS : Unable to mount root fs on unknown-block (22,1)It seems grub2 hasn't tried to mount ext2 as the filesystem and my Compact flash is formatted as ext2. Here is the menuentry of the grub.cfg :
Code:
menuentry "Debian GNU/Linux, linux 2.66.2.9-custom" {
insmod ext2
[code]...
I edited the passwd file to modify the default shell for root from bash to tcshnow when I try to login to root it gives me the following error:"su: /bin/tcsh : No such file or directory"
View 3 Replies View Related