Disks over 2TB

[ojigi]

Let me start by saying that I've read https://github.com/RMerl/asuswrt-merlin.ng/wiki/Disk-formatting#partition-tables a few times now,.

the automatic way using 'fd' doesn't work as it complains that the harddrive is over 2TB (it's 2TB, see below).

Decided to move to Asuswrt-Merlin because there are a few features that I really need (NFS export among those).

I have an old USB disk 4TB (NTFS) that I've been using with stock firmware.
NFS exports requires Linux file systems (ext3 or ext4 ideally), so my plan was to format a 2TB USB disk and then copy from 4TB to 2TB, reformat 4TB (to ext4) and then copy back.

My questions are:

1) why have my 4TB disk been working well for all this time?
2) is the 2TB partition issue only an issue if I format using the Asus router to partition and format? Is there a workaround if I format the disks on a regular Linux system (Ubuntu) taking the GUID/GPT into consideration?
3) whenever I follow the guide in the wiki the mke2fs never finishes. Any ideas?



@RT-AC68U-A2C0:/tmp/home/root# fdisk -l

Disk /dev/sda: 2000.3 GB, 2000398933504 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 1 243201 1953512001 83 Linux


@RT-AC68U-A2C0:/tmp/home/root# mke2fs -t ext4 -O ^has_journal /dev/sda1
mke2fs 1.45.6 (20-Mar-2020)
Creating filesystem with 488378000 4k blocks and 122101760 inodes
Filesystem UUID: 98d3e266-218f-49f9-9722-b8defd8d4f02
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848

Allocating group tables: done
Writing inode tables: client_loop: send disconnect: Broken pipe

 

[ojigi]

I tried to repartition with GPT and then reformat, but it doesn't seem to work (as expected by the documentation on the wiki).


johndoe@RT-AC68U-A2C0:/tmp/mnt# fdisk -l
Found valid GPT with protective MBR; using GPT

Disk /dev/sda: 3907029167 sectors, 1863G
Logical sector size: 512
Disk identifier (GUID): 46da6239-65ee-d94d-a92e-b986ef7548e1
Partition table holds up to 128 entries
First usable sector is 2048, last usable sector is 3907029133

Number Start (sector) End (sector) Size Code Name
1 2048 3907029133 1863G 0700

johndoe@RT-AC68U-A2C0:/tmp/mnt# mount /dev/sda1 /tmp/mnt/x
mount: mounting /dev/sda1 on /tmp/mnt/x failed: Invalid argument

 

[ojigi]

Seems to be related to "metadata_csum" mentioned here: https://unix.stackexchange.com/ques...-dev-sda2-on-mnt-sda2-failed-invalid-argument

@RT-AC68U-A2C0:/tmp/mnt# dmesg|grep sda
sd 0:0:0:0: [sda] Spinning up disk...
sd 0:0:0:0: [sda] 3907029167 512-byte logical blocks: (2.00 TB/1.81 TiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 4f 00 00 00
sd 0:0:0:0: [sda] Assuming drive cache: write through
sd 0:0:0:0: [sda] Assuming drive cache: write through
sda: sda1
sd 0:0:0:0: [sda] Assuming drive cache: write through
sd 0:0:0:0: [sda] Attached SCSI disk
EXT4-fs (sda1): couldn't mount RDWR because of unsupported optional features (400)
EXT3-fs (sda1): error: couldn't mount because of unsupported optional features (2c0)
EXT2-fs (sda1): error: couldn't mount because of unsupported optional features (2c0)
EXT3-fs (sda1): error: couldn't mount because of unsupported optional features (2c0)
EXT4-fs (sda1): couldn't mount RDWR because of unsupported optional features (400)
EXT2-fs (sda1): error: couldn't mount because of unsupported optional features (2c0)
tntfs info (device sda1, pid 1251): ntfs_fill_super(): fail_safe is enabled.

 

[ojigi]

Turning off metadata checksums did the trick! Hard drive mounts without errors after:

tune2fs -O^metadata_csum /dev/sdXn

(replace Xn with whatever is the actual identifier of the USB stick in your Linux system.)

tune2fs wanted me to run "e2fsck -f /dev/sdXn" under than that no surprises.