--- title: "Linux Rescue Mode: Fix Boot, Reset Root Password" description: "Boot the network rescue system to repair a server that won’t start: assemble RAID, mount and chroot, fix fstab or GRUB, and reset a lost root password." url: "https://powerdedi.com/docs/rescue-mode" last_updated: "2026-09-25" publisher: "PowerDedi (https://powerdedi.com)" --- # Repair your server with rescue mode Boot a Debian-based live system to mount your disks, fix boot problems, reset passwords or copy data off. Updated September 25, 2026 · 3 min read · 7 sections ### All guides Filter the guides ### Getting started - [Get started with your dedicated server](https://powerdedi.com/docs/getting-started) ### Server management - [Use the IPMI/KVM console](https://powerdedi.com/docs/ipmi-kvm-console) - [Reinstall the operating system](https://powerdedi.com/docs/reinstall-os) - [Repair your server with rescue mode](https://powerdedi.com/docs/rescue-mode) - [Monitor and repair software RAID](https://powerdedi.com/docs/software-raid) ### Networking - [Configure IPv6 on your server](https://powerdedi.com/docs/ipv6-configuration) - [Test your server’s network speed](https://powerdedi.com/docs/network-speed-test) - [Set up reverse DNS (PTR records)](https://powerdedi.com/docs/reverse-dns) ### Billing - [Pay with cryptocurrency](https://powerdedi.com/docs/pay-with-crypto) ### Security - [Secure your server in the first hour](https://powerdedi.com/docs/secure-your-server) - [Create and use SSH keys](https://powerdedi.com/docs/ssh-keys) Rescue mode boots your server into a Debian-based live system loaded over the network, independent of the installed operating system. Use it to repair a server that doesn’t boot, reset a lost password or copy data off. You need access to the client area and, ideally, an SSH key saved under **Account → SSH keys**. ## Enable rescue mode 1. In the client area, open **Servers**, select the server and open the **Rescue** tab. 2. Your saved SSH keys are installed in the rescue system. A temporary root password also appears on the tab once the system is ready: reveal it with one click; it is deleted after 24 hours. 3. Click **Boot into rescue**: the server restarts into the rescue system, even if the installed system is frozen. Progress shows on the tab. Rescue mode stays active until you switch the server back to booting from disk, as described at the end of this guide. ## Log in to the rescue system The rescue system has its own SSH host key, so your SSH client would warn that the host identification has changed. A separate known-hosts file keeps both keys apart: ```bash ssh -o UserKnownHostsFile=~/.ssh/known_hosts_rescue root@203.0.113.10 ``` The rescue system runs from memory: anything you change outside your mounted disks disappears at the next reboot. ## Identify disks and arrays ```bash lsblk -o NAME,SIZE,TYPE,FSTYPE,MODEL,SERIAL cat /proc/mdstat ``` Device names can differ from those in your installed system, so recognize disks by size, model and serial number. Linux installs use mdadm RAID by default. If `/proc/mdstat` doesn’t list your arrays yet, assemble them: ```bash mdadm --assemble --scan cat /proc/mdstat ``` Arrays may get unusual numbers, such as `md126` or `md127`; that is harmless. If your layout uses LVM, activate it with `vgchange -ay` and list the volumes with `lvs`. > Never run `mdadm --create` on existing disks to “repair” an array. It writes new metadata and can destroy your data. Use `--assemble`, and ask support if an array refuses to start. ## Mount the system and chroot into it Mount the root filesystem on `/mnt`, then read its `/etc/fstab` to see what else to mount. The device names below are examples: ```bash mount /dev/md1 /mnt cat /mnt/etc/fstab mount /dev/md0 /mnt/boot # only if /boot is separate mount /dev/nvme0n1p1 /mnt/boot/efi # only on UEFI systems ``` Bind the kernel filesystems into the mounted system and switch into it. From then on, commands run as if the installed system had booted: ```bash mount --rbind /dev /mnt/dev && mount --make-rslave /mnt/dev mount --rbind /sys /mnt/sys && mount --make-rslave /mnt/sys mount --bind /run /mnt/run mount -t proc proc /mnt/proc chroot /mnt /bin/bash ``` ## Common repairs ### Fix /etc/fstab A wrong UUID or a missing disk in `/etc/fstab` stops the boot. Compare the file with the output of `blkid`, correct it, then check it with `findmnt --verify`. Add the `nofail` option to disks the system can boot without. ### Reinstall the boot loader Find out how the server boots with `[ -d /sys/firmware/efi ] && echo UEFI || echo BIOS`. On Debian and Ubuntu: ```bash grub-install /dev/nvme0n1 && grub-install /dev/nvme1n1 # BIOS: both disks grub-install --target=x86_64-efi --efi-directory=/boot/efi # UEFI update-grub ``` On AlmaLinux and Rocky Linux, run `grub2-mkconfig -o /boot/grub2/grub.cfg`, preceded on BIOS systems by `grub2-install` for each disk. On Proxmox VE installed on ZFS, run `proxmox-boot-tool refresh` instead. ### Reset a password or restore SSH access Run `passwd root` or `passwd alice`, or append your public key to `/root/.ssh/authorized_keys`. On AlmaLinux and Rocky Linux, also run `touch /.autorelabel`: SELinux then relabels the changed files at the next boot, which takes a few extra minutes. Without it, logins can fail. ## ZFS pools Proxmox VE and FreeBSD installed on a ZFS mirror use a ZFS pool instead of mdadm. List the pools available for import, then import yours under `/mnt`: ```bash zpool import zpool import -f -R /mnt rpool ``` Proxmox VE usually names its pool `rpool`; the FreeBSD installer uses `zroot`. Export the pool with `zpool export rpool` before you reboot, or the installed system may refuse to import it. A FreeBSD pool can use features that the rescue system’s ZFS doesn’t support. In that case, or if `zpool` isn’t available, boot the installer ISO of your system from the console and use its live shell. ## Boot from disk again ```bash exit # leave the chroot umount -R /mnt ``` 1. In the **Rescue** tab, click **Boot from disks**. 2. Reboot the server, for example with `reboot` from the rescue shell. 3. Watch the boot on the **Console** tab. If it still stops, the screen shows where, which tells you what to fix next. [← Previous **Reinstall the operating system**](https://powerdedi.com/docs/reinstall-os) [Next → **Monitor and repair software RAID**](https://powerdedi.com/docs/software-raid) **Still stuck?** Customers with an active server open a support ticket: tell us what you tried and an engineer takes it from there, usually within a few hours. [Open a ticket](https://powerdedi.com/account/support) ## Related guides [All guides](https://powerdedi.com/docs) [Server management](https://powerdedi.com/docs/category/server-management) Updated September 25, 2026 ### [Use the IPMI/KVM console](https://powerdedi.com/docs/ipmi-kvm-console) See your server’s screen in the browser, control power, mount an ISO and reach the BIOS, even when the OS won’t boot. 4 min read [Server management](https://powerdedi.com/docs/category/server-management) Updated September 25, 2026 ### [Reinstall the operating system](https://powerdedi.com/docs/reinstall-os) Wipe and reinstall with the operating system, SSH keys and RAID layout you choose. 3 min read [Server management](https://powerdedi.com/docs/category/server-management) Updated September 25, 2026 ### [Monitor and repair software RAID](https://powerdedi.com/docs/software-raid) Check mdadm health, get alerts, swap a failed disk safely and size RAID 6, RAID 10 or RAIDZ2 storage pools. 4 min read --- PowerDedi — Dedicated servers with 10 Gbps unmetered, paid in crypto. Page: https://powerdedi.com/docs/rescue-mode. Index of the site for AI assistants: https://powerdedi.com/llms.txt