Ubuntu Won Boot Read Only File System
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Root filesystem is mounted read simply on kicking
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Try to search in dmesg for errors. For example via
dmesg | less
If there are errors in /etc/fstab the organization can't boot properly and usually comes up in rescue mode. In this style the just drive (root) is mounted as read-only.
Boot into single user mode past selecting your kernel and pressing east to edit and calculation either 1, s, or single to the end of the statement. Hit return and then press b to kicking. In one case you are greeted with a prompt cheque your /etc/fstab to make sure root is readable. The entry for root should expect like this:
UUID=26ab2266-f9f6-40f2-af3f-41f992154ac5 / ext4 defaults ane 1
Additionally check to make sure your other partitions look sane. If those await correct run dmesg to check that it isn't a hard drive problem.
To remount the root book as RW, to make changes y'all tin use the command:
mountain -o remount,rw /
If yous would like remount it to read-write, try to use mount -o remount,rw /
Than means that it is important to check if fstab options are right for new partitions by first un-mounting them them then trying to mount using
mount -a
Call up that the mount point must already exist, otherwise the entry will not mountain on the filesystem
Again, system with wrong /etc/fstab usually boot to safe mode with root filesystem mounted as read but.
In that location tin can be other reasons. Nearly common are failed disk and a corrupt file organisation.
In this is a corrupt filesystem instance (for example if the server abruptly lost power), in many cases such filesystem can be repaired using fsck utility. To determine which filesystem is afflicted (and whether this is filesystem related problem at all) useful information usually tin be recovered from dmesg command output.
The dmesg control is used to write the kernel messages in Linux and other Unixes to standard output (which past default is the display screen). Here is some recommendation on how to use it (How to use the dmesg control -- by The Linux Information Project (LINFO) ):
The dmesg command is used to write the kernel letters in Linux and other Unix-like operating systems to standard output (which by default is the display screen).
A kernel is the cadre of an operating system. It is the start office of the operating system that is loaded into retentivity when a computer boots up (i.e., starts up), and information technology controls virtually everything on a arrangement. The numerous messages generated by the kernel that appear on the display screen as a computer boots upwardly show the hardware devices that the kernel detects and indicate whether it is able to configure them.
dmesg obtains its information past reading the kernel band buffer. A buffer is a portion of a computer'southward memory that is set up aside equally a temporary holding place for data that is being sent to or received from an external device, such as a hard disk drive bulldoze (HDD), printer or keyboard. A ring buffer is a buffer of fixed size for which any new information added to information technology overwrites the oldest data in it.
dmesg tin can be very useful when troubleshooting or just trying to obtain information about the hardware on a arrangement. Its basic syntax is
dmesg [options]Invoking dmesg without any of its options (which are rarely used) causes it to write all the kernel messages to standard output. This usually produces far too many lines to fit into the display screen all at once, and thus only the terminal letters are visible. However, the output can be redirected to the less command through the utilise of a pipe (designated by the vertical bar character), thereby allowing the startup letters to be viewed one screenful at a fourth dimension:
dmesg | lessless allows the output to be moved forward one screenful at a time past pressing the SPACE bar, astern by pressing the b central and removed by pressing the q key. (The more control could have been used here instead of the less control; however, less is newer than more than and has boosted functions, including the ability to return to previous pages of the output.)
When a user encounters a trouble with the system, it tin can be convenient to write the output of dmesg to a file and and so send that file by e-mail to a organisation administrator or other knowledgeable person for assistance. For case, the output could be redirected to a file named boot_messages using the output redirection operator (designated past a rightward facing angle bracket) as follows:
dmesg > boot_messagesBecause of the length of the output of dmesg, it can be convenient to pipage its output to grep, a filter which searches for any lines that incorporate the string (i.east., sequence of characters) post-obit information technology. The -i option can exist used to tell grep to ignore the instance (i.eastward., lower case or upper example) of the letters in the string. For example, the following control lists all references to USB (universal serial bus) devices in the kernel letters:
dmesg | grep -i usbAnd the following tells dmesg to prove all serial ports (which are represented past the cord tty):
dmesg | grep -i ttyThe dmesg and grep combination can as well be used to show how much physical memory (i.e., RAM) is available on the system:
dmesg | grep -i memoryThe following command checks to confirm that the HDD(due south) is running in DMA (direct memory access) mode:
dmesg | grep -i dmaThe output of dmesg is maintained in the log file /var/log/dmesg, and it tin thus also be easily viewed by reading that file with a text editor, such as vi or gedit, or with a command such every bit cat, east.chiliad.,
cat /var/log/dmesg | less
Availability of baseline of the configuration is too very helpful.
Come across also
- lspci, detailed information about all PCI buses and devices in the system
- lsusb, detailed information most USB ports and devices
- uname prints the name, version and other details about the current machine and the operating system
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NEWS CONTENTS
- 20150930 : kick - Why is my filesystem being mounted read-merely in linux ( Oct i, 2010 , Server Error )
- 20121206 : [ubuntu] Edit fstab from recovery trounce - Ubuntu Forums ( [ubuntu] Edit fstab from recovery shell - Ubuntu Forums, December 06, 2012 )
- 20121206 : Idea #18468 Be able to boot into recovery manner and set malformed -etc-fstab - Ubuntu brainstorm ( Idea #18468 Be able to boot into recovery mode and fix malformed -etc-fstab - Ubuntu brainstorm, )
- 210210 : Root partitioning mounted read-only on boot ( )
Old News ;-)
[Sep 30, 2015] boot - Why is my filesystem being mounted read-only in linux
Oct ane, 2010 | Server Fault
Tim
Why is my filesystem being mounted read-only in linux?
I am trying to fix a small linux organization based on Gentoo on a VirtualBox motorcar, as a stride towards deploying the same organisation onto a low-spec Unmarried Board Computer. For some reason, my filesystem is being mounted read-only.
In my /etc/fstab, I have:
/dev/sda1 / ext3 defaults 0 0
none /proc proc defaults 0 0
none /sys sysfs defaults 0 0
none /dev/shm tmpfs defaults 0 0However, one time booted /proc/mounts shows
rootfs / rootfs rw 0 0
/dev/root / ext3 ro,relatime,errors=continue,barrier=0,data=writeback 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
udev /dev tmpfs rw,nosuid,relatime,size=10240k,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,style=620 0 0
none /dev/shm tmpfs rw,relatime 0 0
usbfs /proc/jitney/usb usbfs rw,nosuid,noexec,relatime,devgid=85,devmode=664 0 0
binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc rw,nosuid,nodev,noexec,relatime 0 0(the above may contain errors: there's no practical way to copy and paste)
The partition at /dev/hda1 is clearly being mounted OK, since I tin can read all the information, just it's not beingness mounted as described in fstab. How might I become near diagnosing / resolving this?
Edit: I tin can remount with mount -o remount,rw / and information technology works as expected, except that /proc/mounts reports /dev/root mounted at / rather than /dev/sda1 as I'd await.
If I try to remount with mount -a I go
mount: none already mounted or /sys busy
mount: according to mtab, sysfs is already mounted on /sysEdit ii: I resolved the problem with mount -a (the same error was occuring during startup, it turned out) by changing the sysfs and proc lines to
proc /proc proc [...]
sysfs /sys sysfs [...]Now mount -a doesn't complain, merely it doesn't upshot in a read-write root partition. mount -o remount / does cause the root partition to be remounted, nonetheless.
linux boot gentoo fstabCan you remount the partion rw? mount -o remount,rw / � MattyB October 1 'x at xvi:58
Do you use an initrd? If y'all use one, do you pivot the root file system? � Mircea Vutcovici Mar 22 '11 at 1:06
2You say /dev/sda1 in some spots, /dev/hda1 in other spots. Mixing the 2 up can crusade the issues youre seeing, so make sure everything is referencing the proper device. � Patrick Dec 23 '11 at iv:35
add a annotate |
3 Answers three
activeoldestvotes
upward vote4down voteperhaps it is because the deejay is unclean, try changing:
/dev/sda1 / ext3 defaults 0 0
to
/dev/sda1 / ext3 defaults 0 1
or at least do an fsck and and so reboot
share|ameliorate this respond
answered October 19 'eleven at 17:54freedenizen
1412Did this answer past freedenizen help you? It'southward easy to requite dorsum. Sign upwards to get started.
1
Even if this isnt the cause, the change should still be made. � Patrick December 23 '11 at 6:52
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Oops! I didn't hateful to do this.up vote2down vote
You say it'due south a VirtualBox machine... Does the VirtualBox process have write privileges to the datastore on the host?
mountain -a remounts everything as described in /etc/fstab. If this is not behaving as expected, there may be some output in syslog. Check and mail service here if there is anything relevant.
share|amend this respond
answered October i 'ten at 18:22Aaron Copley
vi,67521844I tin can't seem to find syslog on the machine, I don't know if it's been disabled in the distro I'm adapting, I'll have a wait at re-enabling information technology. There doesn't seem to exist any logging in /var/log, presumably because the device is read-only so nothing can be written. � Tim Oct two 'x at 5:01
And yes, on a different VirtualBox invitee I can mount the device for writing just fine. � Tim Oct ii '10 at 7:07
Oh, right -- /var/log would exist read-but. If only yous could edit /etc/syslog.conf yous tin endeavor logging to a remote host. Only then, if y'all could do that you wouldn't accept a problem. Have you had any luck since this was originally posted? � Aaron Copley Oct 19 '10 at 19:35
add a comment |
up vote1down vote
If your are running Ubuntu then try first removing ntfs-3g and and so install by running - "aptitude install ntfs-config" This usually fixes it. (The problem is that if you installed some other version of ntfs commuter (e.grand. additional options og parted) then it does not accept write capability.)
share|improve this respond
answered Mar 4 '12 at iii:fortyanonyn
111I must acknowledge that the post about ntfs-3g didn't look like much to me.. But information technology was accurate enough to atomic number 82 me to another solution! I just had this same trouble after rebooting a working system. In my example, however, I had to unmerge dosfstols. Best wishes to you all! � user204239 January iii '14 at 16:23
[December 06, 2012] [ubuntu] Edit fstab from recovery shell - Ubuntu Forums
It's telling you that yous can't write, because the filesystem was mounted read-only. Logically, you lot want to remount it with writes enabled, if y'all desire to write.
mount -o remount,rw <your_root_partition such as /dev/sda#> /
user024
To simply requite my feedback, I wanted to apply the six editor to change the fstab file but I couldn't, because of the read only problem.
I tried to remount the book, but in that location was something wrong about what I did. No luck either to copy my fstab.bak file back to fstab. The read only curse.
And then, I tried the following and information technology actualy worked much ameliorate than I hoped: During the Grub listing I pressed "eastward" for editing the commands before booting and I changed the "ro" argument for the drive to rw. So, I pressed ctrl-x to boot.
I expected to face the same "waiting to mount" error, but I didn't. The organization started as normally did.
I sudo gedit-ed the fstab file back to the original with a grinning from one ear to another and rebooted.
The Grub file was dorsum to the original "ro" (read only) argument and I merely came to annals to the forum to write about it, since I 've read about your solution past my phone.
I should say I am using karmic koala with Chow ane.97
Idea #18468 Be able to boot into recovery way and fix malformed -etc-fstab - Ubuntu brainstorm
Idea #18468: Be able to boot into recovery fashion and fix malformed /etc/fstab
- Clarification
- Written report indistinguishable
- Help promote this idea!
Written by dcstar the 6 Mar 09 at 03:49. Category: System. Related project: Nothing/Others. Status: New
Rationale If a user make an error modifying the root filesystem line in their /etc/fstab, they will then always be booted up with the root filesystem in "Read Merely" mode so they cannot edit the file and boot normally.
The simply repair option now is to boot upwards using Live CD/Recovery media, then mount the filesystem and then edit the /etc/fstab file (using sudo privileges). This tin be a bit much to inquire of an inexperienced user.
Tags: boot fstab readonly Recovery
Solution #1: Vanilla fstab file Written by dcstar the half-dozen Mar 09 at 03:49.
I propose that a "vanilla" or "Install" /etc/fstab file be created at install that is available to be used in the "Recovery" menu that Ubuntu now provides.This would allow R/W access to the root filesystem so a user could then fix their system without requiring external boot media and the upshot of mounting/editing their boot disk.
Root sectionalization mounted read-only on boot
Quote:
Originally Posted by mbreith
Yous're doing what .
I have two hard drives on the aforementioned IDE cable, I just switch the jumper on the hdd's to make up one's mind which one is master.Seems like I accept establish the problem, I booted upwardly in runlevel 1, when I tried to remount the root partition,
Lawmaking:mount -n -o remount,rw /
I got an error
Code:
Mount Failed: /dev/hda3 (ext3) and /dev/hdb3 (ext3) both have label /
So I disconnect the debian hdd and fedora boots up fine. I observe it strange that this happens because my fedora /etc/fstab has no reference to hdb!Recommended Links
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Last modified: July, 28, 2019
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