Ubuntu 16.04LTS not seeing / reporting HD properly

lavere · 10-28-2017, 02:40 PM

My computer has two hard drives:

/dev/sda contains my two OS's: Windows 7 and Ubuntu 16.04LTS

/dev/sdb is a 3TB drive that contains only data (Music, Video, DB, etc)

Recently, /dev/sda went down. It went down slowly so that it took me a while to realize what was going on. By the time I had figured it out, I'd had to hard power off several times and I think that might have corrupted /dev/sdb as well as /dev/sda.

I removed the sda drive and replaced it with another of the same size (500GB) and restored the data that I had backed up. I had lost a couple of things (found.000) but nothing too drastic. When I was putting the PC back together, I removed sdb and made him a USB drive so I could have room for my blu-ray drive that had been living outboard.

When I rebooted windows, it seemed to be happy with the new setup and all of the 5 primary partitions on sdb (GUID drive) were visible and all the data seemed to be intact. I ran chkdsk /f on each of the drives to be safe and everything looked OK until I got to the largest drive, Drive H:. Chkdsk put up a fuss about not being able to write to the error log. My heart sank but after doing some reading on this I decided to just let it keep going as everyone seemed to think that stopping it would be a mistake. Drive H: is a big drive (1TB) so I thought it might well take a while.

After a week of waiting, I decided to hell with it and stopped the operation. Booting into Windows, I saw all the files and it seemed to be ok.

I rebooted in Ubuntu. The first thing I noticed was that all 5 drives were not visible in linux. It could see sda ok (naturally, since it booted from it), but sdb only showed 2 of the 5 drives, D: and E:. I ran gparted from a Live CD. It gave me an error message about partitions existing outside of the disk !!!??? Then it said that sdb was unallocated.

Then I ran fdisk -l in an effort to see what was going on and saw this:

Code:

>sudo fdisk -lu /dev/sdb
Disk /dev/sdb: 746.5 GiB, 801569726464 bytes, 1565565872 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
Disklabel type: gpt
Disk identifier: F318B7C0-99AE-46F7-9426-C7496E55D326

Device          Start        End    Sectors   Size Type
/dev/sdb1          34     262177     262144   128M Microsoft reserved
/dev/sdb2      264192 1229064191 1228800000   586G Microsoft basic data
/dev/sdb3  1229064192 1331464191  102400000  48.8G Microsoft basic data
/dev/sdb4  1331464192 1638664191  307200000 146.5G Microsoft basic data
/dev/sdb5  1638664192 3686664191 2048000000 976.6G Microsoft basic data
/dev/sdb6  3686664192 5860530175 2173865984     1T Microsoft basic data

The first indication that something was not right was the 3TB drive being reported as being 746.5GB instead of 3TB. Then (after more reading of course) I noticed that the ends of sdb4, sdb5 and sdb6 were way past the end of the disk. I thought these must be my missing drives. I read some more about ways to fix this but got pretty confused when I realized that Windows was reading it OK but Ubuntu was not.

At that point, I decided to put it out to the forum to get advice.

I'm wondering if the demise of the sda hard drive could have scrambled things on sdb. But if that's the case, why does Win7 still read it OK.
I also wonder if moving the drive from the computer (using sata architecture) to the USB enclosure outside the pc could have anything to do with it.

Any ideas?

lavere · 10-29-2017, 10:49 AM

Here is an image of the Windows Disk Management console for this pc. Windows sees /dev/sdb (Windows Disk 1) normally as opposed to the fdisk info above.

http://www.imageno.com/di9s3fhpsgdwpic.html

jefro · 10-30-2017, 07:35 PM

Placing a drive in a usb caddy could damage a drive if you did any sort of edits. Caddy's may not have the same ability of a motherboard drive chip.
Not even sure your motherboard is OK. Consider known good motherboard to test this drive on again.

Note, edit initial post to keep on zero reply list.

lavere · 11-03-2017, 05:27 PM

Quote:

Originally Posted by jefro

Placing a drive in a usb caddy could damage a drive if you did any sort of edits. Caddy's may not have the same ability of a motherboard drive chip.
Not even sure your motherboard is OK. Consider known good motherboard to test this drive on again.

Note, edit initial post to keep on zero reply list.

As it turns out, you're very close to the mark. I learned a bit from this ordeal.

I finally decided to erase the partitions on the disk (in Windows, where I could see them all). When I started the process, I deleted Drive H, which is a 1TB + partition, but I got back no unallocated space. I deleted the next one with the same outcome. It wasn't apparent for a few more drives, but things were screwed up in Windows, too! When the drive was finally emptied, it reported approx 800GB just like linux!

So now, Windows and Linux are finally agreeing. I did more reading. The USB caddy that I was trying to read the 3TB drive in was a USB2.0 drive and I guess that wouldn't let the pc know the true size of the drive. I put the drive back into the pc into the SATA cables where it used to live. Things were back to normal. I wiped the drive clean and reinstalled all of the data successfully.

I have ordered a USB caddy that has USB3.0 capability and I've ordered a USB3.0 card for the pc to try to fix the situation. It seems to me that this should work as I have a MyBook that is 6TB hooked into this pc and it seems to be working fine.

Many thanks to Linux for pointing out there was a problem!

But since I've made this blunder, I must ask the forum: will a new USB3.0 enclosure with a USB3.0 card in the pc allow me to access this data only drive without further problems?