fdisk shows overlapping partitions

Question

At every boot to start Ubuntu, a partition gets re-mounted more than 1 times, sometimes causing very long boots. Example below:

> dmesg
...
[   21.472020] EXT4-fs (sda5): re-mounted. Opts: errors=remount-ro
...
[   42.021537] EXT4-fs (sda5): re-mounted. Opts: errors=remount-ro,commit=0
...

I suspect there is a problem of overlapping partitions here, regarding sda4 and sda5:

> sudo fdisk -l
Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63      610469      305203+  de  Dell Utility
/dev/sda2          612352    32069631    15728640    7  HPFS/NTFS/exFAT
/dev/sda3   *    32069632   238979788   103455078+   7  HPFS/NTFS/exFAT
/dev/sda4       238983166   625141759   193079297    5  Extended
/dev/sda5       238983168   612630527   186823680   83  Linux
/dev/sda6       612632576   625141759     6254592   82  Linux swap / Solaris

Further details:

> more /etc/fstab
...
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sda6 during installation
UUID=b33be99b-5c9e-449e-ad48-be608aeff001 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda7 during installation
UUID=7c9071cc-b77b-40da-9f80-6b8a9a220cb1 none            swap    sw    

and

> mount
/dev/sda5 on / type ext4 (rw,errors=remount-ro,commit=0)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
fusectl 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)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/piero/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=piero)

I am Running Ubuntu Oneiric + LXDE on
Dell Studio XPS machine 64-bit, dual booting with Windows 7.

A months ago, I resized the Ubuntu partition and maybe I messed up something by doing that.

Do you have any idea, why this long booting is happening?

Answer 1

Don't worry about sda5, it is an extended partition. The FAT table has only space for 4 entries, if you want more than 4 partitions, you create an extended partition (sda4) in your case. Such an extended partition has its own partition table in turn. Partition sda5 and sda6 are located inside sda4. Think of it as a container keeping partions.

Partition sda1, 2 and 3 are called primary partitions, they directly use a 'FAT-slot'.

Remounting sda5 shouldn´t take very long; the timestamp to the next line is probably subsecond, but you cut those from your sniplet. The timestamps only reliably show the start of a certain action.

Check this thread to further analyse what takes the most time during boot.