4TB HD on Kubuntu 14.10 - shows as 2tb (1.7 actually) but Fdisk says 4TB.

cilbuper · 12-09-2015, 04:58 AM

I've read a number of different reasons for this drive not showing up. I'm running a WD 4Tb Red NAS drive - not pro version (ext4 I believe, possibly ext3). I have 2 of these in a 3+ year old Zyxel NAS320 which originally only supported 2TB, but reads my 4TB fine.

My system is a Asus P8Z77-V Deluxe and a 3770K. I'm not sure the Bios, but I checked about 4-6 months ago and I believe it was updated at that point.

I'm also considering getting a 5-6TB external HD and am wondering if that is going to work with this system.

The major question I have is if I have to re-format/partition the drive, will I have to copy all the data off it when doing that or is there a way to retain the info?

syg00 · 12-09-2015, 05:15 AM

And we are supposed to precognisant ?.
What does "fdisk -l" (or parted) have to say.

First guess would be non-gpt partitioning.

cilbuper · 12-09-2015, 05:47 AM

Quote:

Originally Posted by syg00

And we are supposed to precognisant ?.
What does "fdisk -l" (or parted) have to say.

First guess would be non-gpt partitioning.

I'm Sorry, I apologize. I didn't think I needed to say more than that Fdisk shows 4TB and that it is 83 Linux (ext3 or EXT4).

Disk /dev/sdf: 4000.8 GB, 4000787030016 bytes
90 heads, 3 sectors/track, 28940878 cylinders, total 7814037168 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
Disk identifier: 0x1ffd8ae3

Device Boot Start End Blocks Id System
/dev/sdf1 2048 4294967294 2147482623+ 83 Linux

ON another note, I just loaded gparted and it looks like it is giving me the option to expand the 2TB sector (1.64 un-allocated). THe strange thing is that when I installed the drive, I created the partition in Fdisk, wrote changes, then did a mkfs.ext4 /dev/sdxx. When I created the partitions, I did all defaults, which should have taken up all the drive space from what I have experienced in the past.

In gparted, there is a padlock next to the partition and FS type which I guess is there because it is mounted at the time. If I unmount the drive, open gparted again, resize to maximum, is there anything that I should know or be worried about before doing this?

Thanks again for the help and I'm sorry I didin't include the Fdisk info - I'm not doing admin work a regularaly as I had been so some things slip my mind. :

syg00 · 12-09-2015, 06:10 AM

That doesn't show what I expected - no line like "Disklabel type: "?.

I'll presume "msdos" - i.e non-gpt. If so, 2 Gig is the limit. To get to the rest you'll need to re-define the partition structure as gpt - there are tools that attempt conversion "in-place"; gdisk for example. That may be safe for your data, maybe not. With only the one partition, I'd probably try it - after a back up.

Update: forgot to mention, do it all from a liveCD.

smallpond · 12-09-2015, 06:27 AM

With 512e drives you need to make sure that your partitions are aligned on 8-sector boundaries. Parted will try to do this by default.

Emerson · 12-09-2015, 06:37 AM

Why partition if the drive is used for a single filesystem?

smallpond · 12-09-2015, 08:27 AM

Quote:

Originally Posted by Emerson

Why partition if the drive is used for a single filesystem?

Why label bags in your freezer?

Emerson · 12-09-2015, 03:38 PM

Code:

# file -s /dev/sdb
/dev/sdb: SGI XFS filesystem data (blksz 4096, inosz 256, v2 dirs)

# xfs_admin -l /dev/sdb
label = "home"

Maybe it helps if you put a bag into another bag when dealing with goods in the freezer. In technical world adding another layer is usually adding another point of failure.

cilbuper · 12-09-2015, 09:29 PM

Just out of curiosity, I have has some really strange occurances on this system with drives vanishing and becoming un-recoverable to my methods (somewhat advanced, did this at work for 3-4 years). The data has just been "gone" with what seems corrupted data in place.

On a side note, when I installed another 4TB drive (one of my original 4TB reds) about 15 months ago, it seemed to partition the whole 4TB w/o problem and I used the same method this time.

Could this be a sign of a bad drive or is this more of an OS issue?

Thanks again to those who help. I appreciate everyone who has given assistance here and in the past!

jmgibson1981 · 12-13-2015, 11:43 AM

Quote:

Originally Posted by smallpond

Why label bags in your freezer?

Who labels bags in the freezer. It's more exciting to guess...

roy_lt_69 · 12-14-2015, 06:34 PM

I recalled that fdisk had problems with GPT drives in the past, has this been fixed?
Otherwise, I would only use gdisk or gparted.

As for the corrupted data, it could be loose cable, hd about to die, improper shutdown of Linux, etc. Check your logs for errors as some errors will show up there!
So I would suggest doing a full backup and then scanning the disks to see if everything is fine (from a Live CD/DVD).