[Solved]Root filesystem read-only at boot

Question

Hi,
I can't boot arch. Root filesystem is mounted ro, so nothing works properly. Last boot I make a pacman -Syu without incidences. A few weeks ago I make manual intervention  (filesystem upgrade - manual intervention required from latest news). I think that last new (Users of unofficial kernels must enable devtmpfs support) is not the problem  since I don't complile the kernel.
dmesg show 2 mount operations to /dev/sda3 (my root partition, EXT4 fs).
mtab have 2 entrys with /sda3. The last shown "ro" flag, and some strange parameters  for me .
Maybe is a disk problem? How can I remove this flag, or remount in rw mode?
umount -f don't work.
I use a dual boot with GRUB, and second system is  W7.
Thanks in advanced.
Last edited by HermesT (2012-01-14 19:05:56)

Answer 1

Some extra info:
from dmesg
[ 1.237581] sda: sda1 sda2 sda3 sda4 < sda5 >
[ 1.829594] EXT4-fs (sda3): mounted filesystem with ordered data mode. Opts: (null)
[ 5.722599] EXT4-fs (sda3): re-mounted. Opts: user_xattr,acl,barrier=1,data=ordered.
mtab
rootfs / rootfs rw 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
/sys /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,nosuid,relatime,size=10240k,nr_inodes=215507,mode=755 0 0
/run /run tmpfs rw,nosuid,nodev,relatime,size=10240k,mode=755 0 0
/dev/sda3 / ext4 ro,relatime,user_xattr,acl,barrier=1,data=ordered 0 0
devpts /dev/pts devpts rw,relatime,mode=600,ptmxmode=000 0 0
shm /dev/shm tmpfs rw,nosuid,nodev,relatime 0 0
/dev/sda1 /media/SYSTEM fuseblk rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 0 0
/dev/sda2 /media/COMPAQ fuseblk rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 0 0
/dev/sda5 /media/Almacen fuseblk rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 0 0
* please, note that rootfs (?) is the same partition as /dev/sda3, like can be seen in df output.
df
S.ficheros 1K-bloques Usado Disponible Uso% Montado en
rootfs 21096088 12132788 7891664 61% /
udev 10240 0 10240 0% /dev
/run 10240 252 9988 3% /run
/dev/sda3 21096088 12132788 7891664 61% /
shm 1550516 0 1550516 0% /dev/shm
/dev/sda1 102396 25744 76652 26% /media/SYSTEM
/dev/sda2 54772576 36097780 18674796 66% /media/COMPAQ
/dev/sda5 548819964 142760132 406059832 27% /media/Almacen