Reset root password using rescue mode

Dezembro 31st, 2018

1. Check the partitions and find your drive using lsblk or fdisk -l

sysresccd ~ # lsblk

NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0   111.8G  0 disk
├─sda1   8:2    0       2G  0 part
├─sda2   8:3    0   109.6G  0 part
└─sda3   8:1    0     256M  0 part
sdb      8:16   0   931.5G  0 disk
sdc      8:32   0   931.5G  0 disk

If you using LVM

sysresccd ~ # lvscan

ACTIVE '/dev/VolGroup00/LogVol00' [230.75 GiB] inherit
ACTIVE '/dev/VolGroup00/LogVol01' [1.94 GiB] inherit

2. Mount the Partition temporarily

sysresccd ~ # mount /dev/sda2 /mnt
sysresccd ~ # SHELL=/bin/sh
sysresccd ~ # chroot /mnt

3. Once the Partition is mounted, let’s reset password.

sysresccd ~ # passwd root
New password:
Retype new password:

4. Another example, your OS failed and you need backups. After the partition is mounted:

sysresccd ~ # cd /home (the folder that you have the files)
sysresccd ~ # zip -r backups.zip FolderWithYourFiles

Now you can login via FTP using the rescue credentials, go to the folder ( In this case /home ) and download the file you just zipped (backups.zip)