/dev/mapper/tmuat--vg-root / ext4 ro,relatime,errors=remount-ro,data=ordered 0 0

---------------------------

I am using Ubuntu 12.04.4 LTS(Kernel version 3.11.0-15-generic), when i tried to create file in my home directory /home/user
I got the follwing error

$touch a
touch: cannot touch `a': Read-only file system

$sudo mount
sudo: unable to open /var/lib/sudo/user/1: Read-only file system
/dev/mapper/tmuat--vg-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/sda1 on /boot type ext2 (rw)
overflow on /tmp type tmpfs (rw,size=1048576,mode=1777)
/usr/tmp on /tmp type ext4 (rw)
/home/user/.Private on /home/user type ecryptfs (ecryptfs_check_dev_ruid,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs,ecryptfs_sig =3951423444cb6100,ecryptfs_fnek_sig=e154d6ff1a7033bc)

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.

$sudo cat /etc/mtab

sudo: unable to open /var/lib/sudo/user/1: Read-only file system
/dev/mapper/tmuat--vg-root / ext4 rw,errors=remount-ro 0 0
proc /proc proc rw,noexec,nosuid,nodev 0 0
sysfs /sys sysfs rw,noexec,nosuid,nodev 0 0
none /sys/fs/fuse/connections fusectl rw 0 0
none /sys/kernel/debug debugfs rw 0 0
none /sys/kernel/security securityfs rw 0 0
udev /dev devtmpfs rw,mode=0755 0 0
devpts /dev/pts devpts rw,noexec,nosuid,gid=5,mode=0620 0 0
tmpfs /run tmpfs rw,noexec,nosuid,size=10%,mode=0755 0 0
none /run/lock tmpfs rw,noexec,nosuid,nodev,size=5242880 0 0
none /run/shm tmpfs rw,nosuid,nodev 0 0
/dev/sda1 /boot ext2 rw 0 0
overflow /tmp tmpfs rw,size=1048576,mode=1777 0 0
/dev/loop0 /tmp ext4 rw 0 0
/home/user/.Private /home/user ecryptfs ecryptfs_check_dev_ruid,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,ecryptfs_unlink_sigs,ecryptfs_sig= 3951423444cb6100,ecryptfs_fnek_sig=e154d6ff1a7033bc 0 0

$sudo cat /proc/mounts
sudo: unable to open /var/lib/sudo/user/1: Read-only file system
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=2011392k,nr_inodes=502848,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,relatime,size=809468k,mode=755 0 0
/dev/mapper/tmuat--vg-root / ext4 ro,relatime,errors=remount-ro,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/sda1 /boot ext2 rw,relatime,errors=continue,user_xattr,acl 0 0
overflow /tmp tmpfs rw,relatime,size=1024k,nr_inodes=493116 0 0
/dev/loop0 /tmp ext4 ro,relatime,data=ordered 0 0
/home/user/.Private /home/user ecryptfs ro,relatime,ecryptfs_fnek_sig=e154d6ff1a7033bc,ecryptfs_sig=3951423444cb6100,ecryptfs_cipher=aes,ecr yptfs_key_bytes=16,ecryptfs_unlink_sigs 0 0



$df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/tmuat--vg-root 144G 5.6G 131G 5% /
udev 2.0G 4.0K 2.0G 1% /dev
tmpfs 791M 268K 791M 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 2.0G 4.0K 2.0G 1% /run/shm
/dev/sda1 236M 36M 188M 17% /boot
overflow 2.0G 4.2M 1.8G 1% /tmp
/dev/loop0 2.0G 4.2M 1.8G 1% /tmp
/home/user/.Private 144G 5.6G 131G 5% /home/user

$dmesg
[3636030.945621] ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-30]
[3636030.945957] ecryptfs_write_end: Error encrypting page (upper index [0x000000000000000c])
[3636031.015792] ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-30]
[3636031.016400] ecryptfs_write_end: Error encrypting page (upper index [0x000000000000000c])
[3636031.016696] ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-30]
[3636031.017053] ecryptfs_write_end: Error encrypting page (upper index [0x000000000000000c])
[3636031.017136] ecryptfs_encrypt_page: Error attempting to write lower page; rc = [-30]
[3636031.017461] ecryptfs_write_end: Error encrypting page (upper index [0x000000000000000c])



I found /dev/mapper/tmuat--vg-root / ext4 ro,relatime,errors=remount-ro,data=ordered 0 0 as ro.
Can you plese help me to fix this issue for changing ro to rw. Thanks in advance.

should get your filesystem read writable again. But before doing this I would check the reason why the root system is read only. Maybe the filesystem got damaged?