3TB WD AF[4096blks]Hdd ASUS P7P55d MoBo non-UEFI and 4GB ram.

I tried to install xp pro 64bit, but didn't complete because of Windoze not seeing the whole drive. I installed Ubuntu 14.10 LTS and used the whole drive as ext4, no other partitions. Worked for months.

After some kernel upgrade, seemingly automatic, I get a 'missing OS' error on boot and cannot mount the drive.

Using tools from LiveCd, PartedMagic and SysRescueCd, I find I had corrupt superblock, overlapping partitions, bad geometry and other errors. Searched the web for weeks now, trying every tip, trick and code until one suggested I fix my errors by changing to ext2 file system. I used the code and fubar'd my inodes and journal and filesystem.

Is it possible to change back to ext4 without further damage?

ubuntu@ubuntu:~$ sudo fdisk /dev/sda

The size of this disk is 2.7 TiB (3000592982016 bytes). DOS partition table format can not be used on drives for volumes larger than 2199023255040 bytes for 512-byte sectors. Use GUID partition table format (GPT).

ubuntu@ubuntu:~$ sudo fdisk -l /dev/sda

Disk /dev/sda: 2.7 TiB, 3000592982016 bytes, 5860533168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0xa76529e9

Device Boot Start End Sectors Size Id Type /dev/sda1 * 505856 4295473150 4294967295 2T 83 Linux

sysrsccd gdisk -l output with lousy formatting GPT fdisk (gdisk) version 1.0.0

Partition table scan: MBR: MBR only BSD: not present APM: not present GPT: not present

Found invalid GPT and valid MBR; converting MBR to GPT format in memory.

Disk /dev/sda: 5860533168 sectors, 2.7 TiB Logical sector size: 512 bytes Disk identifier (GUID): EC4893A3-AD27-473D-931C-50C03164D378 Partition table holds up to 128 entries First usable sector is 34, last usable sector is 5860533134 Partitions will be aligned on 2048-sector boundaries Total free space is 1565565806 sectors (746.5 GiB)

Number Start (sector) End (sector) Size Code Name 1 505856 4295473150 2.0 TiB 8300 Linux filesystem

Now I will try to type in the URL's that I have from a few days after the crash and today ( July19th)



Sorry about the mess.

  • Can you get us at least the output of fdisk command that we cann see what partition scheme do you have currently? And please reformat the text, it's way tooooo long!!!! – KernelPanic Jul 16 '15 at 6:24
  • How can I do that from Ubuntu LiveCd? Right now I am on my brother's win7 laptop, testdisk searching on 3tb drive in tower, running LiveCd. – Wayne King Jul 16 '15 at 19:25
  • Post this also & preserve formatting so we can easily read it. sudo gdisk -l /dev/sda – oldfred Jul 17 '15 at 15:56
  • I found one of the url #'s from boot-repair, maybe will help -11779238 – Wayne King Jul 20 '15 at 0:07
  • @oldfred I only have 5 minutes? Here Goes – Wayne King Jul 20 '15 at 3:41

I installed Ubuntu 14.10 LTS and used the whole drive, but I don't think I chose LVM, and just formatted the whole drive as ext4, no swap or other partitions. Worked for months with no problems.

Seems all fine to me. LVM is not needed and Linux/Ubuntu will happily play along. ( What is LVM and what is it used for? )

Is it possible to change back to ext4 without further damage?

Generic answer: From the Live session mount your disk and create a backup of your personal data. And then format and re-install your system. All you loose is settings and software you installed afterwards. If that includes Apache or MySQL it might be worth it saving the settings and configs from those too.

It is of course also possible to create a dd copy of the disk though you would need another 3Tb+ disk to store it... might be a bit too difficult.

until one suggested I fix my errors by changing to ext2 file system.

Do not do this since it will format your disk.

Using tools from LiveCd, PartedMagic and SysRescueCd

I have one more suggestion: testdisk. Besides restoring lost files it can also repair partitions. You can install and use it from a live session.

I would focus on getting a backup made from your files and then start with a clean new install.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.