I have a second hard drive installed in my hardware which I can't access from Debian (not mounted)

Question

I just installed Debian but I had some problem during the installation. I first installed my OS on HDD cause I wanted a dualboot with Windows (which WAS located on the SSD) but I couldn't complete it so I decided to say goodbye to Windows and install Debian it again on SSD.

Now in my desktop I can see both hard drives but I can't mount the HDD.

I'll paste some relevant information:

$ sudo fdisk -l
Disk /dev/sdb: 89.4 GiB, 96029466624 bytes, 187557552 sectors
Disk model: KINGSTON RBU-SNS
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: dos
Disk identifier: 0x34f08e2e

Device     Boot     Start       End   Sectors  Size Id Type
/dev/sdb1  *         2048 185556991 185554944 88.5G 83 Linux
/dev/sdb2       185559038 187555839   1996802  975M  5 Extended
/dev/sdb5       185559040 187555839   1996800  975M 82 Linux swap / Solaris


Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: ST1000LM024 HN-M
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: 0x55786839

Device     Boot      Start        End    Sectors   Size Id Type
/dev/sda1             2048 1951522815 1951520768 930.6G 83 Linux
/dev/sda2       1951524862 1953523711    1998850   976M  5 Extended
/dev/sda5       1951524864 1953523711    1998848   976M 82 Linux swap / Solaris

Partition 2 does not start on physical sector boundary.

The drive I'm trying to access is /dev/sda

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            5.8G     0  5.8G   0% /dev
tmpfs           1.2G  9.4M  1.2G   1% /run
/dev/sdb1        87G  5.4G   77G   7% /
tmpfs           5.9G   60M  5.8G   1% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           5.9G     0  5.9G   0% /sys/fs/cgroup
tmpfs           1.2G   20K  1.2G   1% /run/user/1000

Here's what I tried:

~$ sudo fsck.ext4 -f /dev/sda
e2fsck 1.44.5 (15-Dec-2018)
ext2fs_open2: Bad magic number in super-block
fsck.ext4: Superblock invalid, trying backup blocks...
fsck.ext4: Bad magic number in super-block while trying to open /dev/sda

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem.  If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>
 or
    e2fsck -b 32768 <device>

Found a dos partition table in /dev/sda

~$ sudo resize2fs /dev/sda 8193
resize2fs 1.44.5 (15-Dec-2018)
resize2fs: Bad magic number in super-block while trying to open /dev/sda
Couldn't find valid filesystem superblock.

~$ sudo resize2fs /dev/sda 32768
resize2fs 1.44.5 (15-Dec-2018)
resize2fs: Bad magic number in super-block while trying to open /dev/sda
Couldn't find valid filesystem superblock.

inside mount output I fount the other drive infos:

/dev/sdb1 on / type ext4 (rw,relatime,errors=remount-ro)

So I wrote:

sudo mount /dev/sda1 /

And the hard disk icon on my desktop disappeared. After a reboot everything's back as it was, I can see the icon, I can't access the driver. If I click on the Icon:

Failed to mount "999 GB Volume" Not authorized to perform operation

Please help

Answer 1

Since you just installed Debian and have no important data on this computer, I guess you can experience and afford to make mistakes. You don't understand filesystems and mounting at all, and this is your chance to learn about it.

First, /dev/sda is partitioned. According to your fdisk output, the partitions are

/dev/sda1             2048 1951522815 1951520768 930.6G 83 Linux
/dev/sda2       1951524862 1953523711    1998850   976M  5 Extended
/dev/sda5       1951524864 1953523711    1998848   976M 82 Linux swap / Solaris

I guess that /dev/sda1 has already been formatted as a filesystem. To be certain, and if there is nothing worth keeping on that disk, you can create a filesystem yourself:

mkfs -t ext4 /dev/sda1

If /dev/sda1 contains a filesystem already, the command will complain, since it doesn't want overwrite potentially important data. You can force mkfs to overwrite data, but I'd say to leave it if you get complaints.

Next, to use the filesystem, you must mount it. Mounting means integrating a separate filesystem in your existing filesystem tree. To do that, you need a so-called mount point. You create a directory, for example /mnt/data, which will be your mount point. It should be empty, since mounting a filesystem will hide (though not remove) all files and directories that exist in the mount point. Therefore, try this:

mkdir /mnt/data
mount /dev/sda1 /mnt/data

Now it's mounted, and the df command will list it. You can cd /mnt/data and create files and directories. Whatever you create under /mnt/data will reside on /dev/sda1 (as long as it's mounted).