how to fix the db.sqlite file in nixos?

Question

[root@nixos:/mnt/etc/nixos]# lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda      8:0    0   50G  0 disk 
├─sda1   8:1    0  512M  0 part /boot
│                               /boot
├─sda2   8:2    0 49.5G  0 part /nix/store
│                               /
└─sda3   8:3    0  689K  0 part /mnt
sr0     11:0    1  2.6G  0 rom  

[root@nixos:/mnt/etc/nixos]# cd /nix/store

[root@nixos:/nix/store]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        511M     0  511M   0% /dev
tmpfs           5.0G  8.0K  5.0G   1% /dev/shm
tmpfs           2.5G  3.2M  2.5G   1% /run
tmpfs           5.0G  1.2M  5.0G   1% /run/wrappers
/dev/sda2        49G  8.3G   38G  18% /
efivarfs        256K   23K  229K   9% /sys/firmware/efi/efivars
/dev/sda1       511M   23M  489M   5% /boot
tmpfs          1021M   60K 1021M   1% /run/user/1000
/dev/sda3       656K  641K     0 100% /mnt

[root@nixos:/nix/store]# cd /mnt/etc/nixos

[root@nixos:/mnt/etc/nixos]# sudo nixos-install
building the configuration in /mnt/etc/nixos/configuration.nix...
error: setting journal mode: database or disk is full, database or disk is full (in '/mnt/nix/var/nix/db/db.sqlite')

there seems to be a issue with some config which isnt allowing me to use sudo nixos-install whenever i try it it simply gives a error saying there is some issue with it.

these are some debugging attempts

i tried troubleshooting with chatgpt. tried to delete the file and remade it during the next command call tried to remake the partition with larger storage. (it still shows 0 available space)

PS: Since im on a virtualbox im ready to reinstall the entire thing from scratch if need be (similiar to the last 12 times)