reinstalling ubuntu 13.10 without losing data

If you look at https://wiki.ubuntu.com/Releases you can see that Ubuntu 13.10 is supported only until July 2014. I recommend that you install Ubuntu 14.04 LTS (supported until April 2019) or Ubuntu 12.04 LTS (supported until April 2017).

If you install 14.04, you must not execute the command "do-release-upgrade -d" as that would again upgrade to the development release 14.10 and you would run into the same problems that you currently have.

Do you have an overview in which directories the data are located that you want to keep?
I recommend that you copy these data to external media (e.g. a USB hard disk), do a clean installation of Ubuntu 14.04, and then copy the data back.

Yes, I installed ubuntu 14.04 before upgrading.

Can i roll back this Ubuntu 14.04 from 14.10 ?

I have all data in home directories and I dont know my RAID system in PC.

Help me out

Regards,

HARESH AJANI

Your backups will assure data integrity. You do have backups right? your data is important to you?

Yes, My data is important.

I dont know how to install in RAID system.

if possible let me know how can I roll back to 14.10 to 14.04 ?

A downgrade or rollback from one Ubuntu release to a lower one is not supported.
The only reasonable procedure is a new installation.

It should not make any difference whether you have a RAID system in your computer or not.

The terminal commands

df -h
sudo fdisk -l

should provide some information about the disks in your system.

ajanihar@haresh:~$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/md126 241G 18G 211G 8% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
udev 3.9G 4.0K 3.9G 1% /dev
tmpfs 793M 1.2M 792M 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 3.9G 29M 3.9G 1% /run/shm
none 100M 68K 100M 1% /run/user
/dev/md127 669G 21G 615G 4% /home

ajanihar@haresh:~$ sudo fdisk -l
[sudo] password for ajanihar:

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00079e76

   Device Boot Start End Blocks Id System
/dev/sda1 * 63 512007614 256003776 fd Linux raid autodetect
/dev/sda2 512007615 528008354 8000370 82 Linux swap / Solaris
/dev/sda3 528008355 1953525167 712758406+ fd Linux raid autodetect

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a91ad

   Device Boot Start End Blocks Id System
/dev/sdb1 * 63 512007614 256003776 fd Linux raid autodetect
/dev/sdb2 512007615 528008354 8000370 82 Linux swap / Solaris
/dev/sdb3 528008355 1953525167 712758406+ fd Linux raid autodetect

Disk /dev/md127: 729.9 GB, 729864536064 bytes
2 heads, 4 sectors/track, 178189584 cylinders, total 1425516672 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/md127 doesn't contain a valid partition table

Disk /dev/md126: 262.1 GB, 262147801088 bytes
2 heads, 4 sectors/track, 64000928 cylinders, total 512007424 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/md126 doesn't contain a valid partition table

The only way to roll back is to reinstall. This is the same with Windows too.

If your data is important, why do you not have a backup copy?

After copying your important data to a backup device, you should be able to do a new installation with a supported release. And during that installation you should be able to configure your RAID system the same way as it is now, with similar steps as they were done when that system was installed. If you haven't done that yourself, maybe you can ask the person who did that in the past to do it again, providing explanations to you?