I am very new to linux; I have a server running Ubuntu 12.04.5 LTS (GNU/Linux 3.2.0-72-generic-pae i686)

I mistakenly plugged in a MSA 500 (Data Storage box) to this linux server and then subsequently unplugged it, and now anything I try todo I get Read Only errors.

I believe the system has remounted my partition as ro and I need to un-mount and run fsck, but I am unsure how todo this exactly. Also do I need to use a Live CD to boot into?

I will paste the results of what I have found below. I have found:


/dev/mapper/pontus-root / ext4 ro,relatime,errors=remount-ro,user_xattr,acl,barrier=1,data=ordered 0 0


Complete Output


root@pontus:/etc# cat fstab
# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
/dev/mapper/pontus-root / ext4 errors=remount-ro 0 1
# /boot was on /dev/cciss/c0d0p1 during installation
UUID=c6a58b59-56d8-4a02-ae5f-f2e8b322c8d9 /boot ext2 defaults 0 2
/dev/mapper/pontus-swap_1 none swap sw 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto,exec,utf8 0 0
root@pontus:/etc# cat /proc/mounts
rootfs / rootfs rw 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,relatime,size=2963296k,nr_inodes=202678,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,nosuid,noexec,relatime,size=594412k,mode=755 0 0
/dev/mapper/pontus-root / ext4 ro,relatime,errors=remount-ro,user_xattr,acl,barrier=1,data=ordered 0 0
none /sys/fs/fuse/connections fusectl rw,relatime 0 0
none /sys/kernel/debug debugfs rw,relatime 0 0
none /sys/kernel/security securityfs rw,relatime 0 0
none /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
none /run/shm tmpfs rw,nosuid,nodev,relatime 0 0
/dev/cciss/c0d0p1 /boot ext2 rw,relatime,errors=continue 0 0
//venus/E$/Icinga_Backups /mnt cifs rw,relatime,sec=ntlmi,unc=\\venus\E$,username=administrator,uid=0,noforceuid,gid=0,noforcegid,addr=1 0.1.1.42,file_mode=0755,dir_mode=0755,nounix,serverino,rsize=61440,wsize=16580,actimeo=1 0 0


root@pontus:/etc/icinga/objects# fsck
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/mapper/pontus-root: recovering journal
fsck.ext4: Bad magic number in super-block while trying to re-open /dev/mapper/pontus-root
Signal (11) SIGSEGV si_code=SEGV_MAPERR fault addr=0x61
fsck.ext4[0x806fdc6]
[0x54d40c]
/lib/i386-linux-gnu/libext2fs.so.2(ext2fs_mmp_stop+0x27)[0x7b9c37]
fsck.ext4(fatal_error+0x4f)[0x80672af]
fsck.ext4(e2fsck_run_ext3_journal+0x27e)[0x80667de]
fsck.ext4(main+0x6ac)[0x804f21c]
/lib/i386-linux-gnu/libc.so.6(__libc_start_main+0xf3)[0x2ae4d3]
fsck.ext4[0x80515ed]

Thank you for any help/ ideas

Could you post the output of "mount" so I can see what is currently mounted?

You can remount a partition like this,
However, if it is your root partition, you may just have to reboot, You cannot unmount your root partition while the system is running. I don't believe you can remount either, but I've never tried. If you need to run fsck on a partition it will need to be unmounted. If this is your root partition you will have to do this from a boot disk.

1 members found this post helpful.

Thanks for the help.

I am suppose to leave for vacation tomo and if I can't get this fixed that is out!

I see your cmd, on mount, but honestly I am not sure what the /partition/identifier /mount/point exactly means

Thanks again, info u requested below


root@pontus:/home/ezine# mount
/dev/mapper/pontus-root on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/cciss/c0d0p1 on /boot type ext2 (rw)
//venus/E$/Icinga_Backups on /mnt type cifs (rw)

mount: warning: /etc/mtab is not writable (e.g. read-only filesystem).
It's possible that information reported by mount(8) is not
up to date. For actual information about system mount points
check the /proc/mounts file.

You can comment out the existing line with a #
and reboot with no tmpfs line in /etc/fstab (in that case it will use the default mount at /dev/shm )
or you can mount the tmpfs in ram instead, with this line:
This quote from https://wiki.archlinux.org/index.php/Tmpfs
might be useful for your server...

post deleted

The /tmp reference is a symptom, not the real problem. As /tmp is not specifically mounted elsewhere, it is still a sub directory to the root filesystem - which is mounted ro (the fstab option is why).
fsck on the root is best done from a liveCD. Note that fsck ensures the integrity of the filesystem - not necessarily the individual files. I'm guessing you don't have a recent backup you can restore.