Mounting an External Drive (Linux)

If a failed server still has intact drives, our technicians can attach them to your new Linux server. This guide shows how to detect, mount and copy data from them – without network access to the old server.

Important — follow this order: Install the operating system on the new server completely before letting us know the old drives can be connected. If the drives are attached before the OS installation, the installer may detect the wrong disks and irreversibly overwrite the old data.

Overview

Phase	What happens
1. Detect the drive	Find the new device name of the attached drive
2. Assemble RAID (if applicable)	Reactivate software RAID arrays from the old server
3. Mount the partition	Mount the old drive's partitions into the new system
4. Transfer data	Copy files, configurations, and databases to the new server

Step 1: Detect the drive

Find the device name of the newly attached drive.

Terminal

lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT,LABEL

The new drive will appear as an additional device — e.g. /dev/sdb, /dev/sdc, or for NVMe as /dev/nvme1n1. For further identification check the partition table:

Terminal

fdisk -l /dev/sdb

Step 2a: No RAID — mount partitions directly

For servers without software RAID: mount partitions directly.

Terminal

mkdir -p /mnt/oldsystem mount /dev/sdb3 /mnt/oldsystem

If a separate /boot partition exists, mount it too:

Terminal

mount /dev/sdb1 /mnt/oldsystem/boot

Adjust sdb1 and sdb3 to match the actual partition names from the lsblk output.

Step 2b: Software RAID — assemble arrays

For servers with software RAID: reactivate RAID arrays before mounting.

Terminal

apt install mdadm # Debian/Ubuntu dnf install mdadm # AlmaLinux/Rocky Linux mdadm --assemble --scan cat /proc/mdstat

If the automatic scan fails, assemble the RAID manually:

Terminal

mdadm --assemble /dev/md0 /dev/sdb2 /dev/sdc2

If only one drive of a RAID-1 set is available, force-assemble in degraded mode:

Terminal

mdadm --assemble --force /dev/md0 /dev/sdb2

Then mount the RAID partition:

Terminal

mkdir -p /mnt/oldsystem mount /dev/md0 /mnt/oldsystem

Step 3: Activate LVM volumes (if applicable)

If the old server used LVM, activate the volumes before mounting.

Terminal

pvs vgs lvs vgchange -ay lvscan

Terminal

mount /dev/vg_oldserver/lv_root /mnt/oldsystem

Step 4: Check the filesystem (recommended)

Run fsck before migrating — especially important after an unclean shutdown.

fsck must only be run on unmounted partitions. Unmount first if you already mounted in step 2.

Terminal

umount /mnt/oldsystem fsck -y /dev/sdb3 mount /dev/sdb3 /mnt/oldsystem

Step 5: Transfer data to the new server

Copy files, configs, and databases from the mounted old drive.

Web files

Terminal

rsync -av /mnt/oldsystem/var/www/ /var/www/

Configuration files

Terminal

cp /mnt/oldsystem/etc/nginx/nginx.conf /etc/nginx/nginx.conf cp -r /mnt/oldsystem/etc/nginx/sites-available/ /etc/nginx/sites-available/ cp /mnt/oldsystem/etc/mysql/my.cnf /etc/mysql/my.cnf

Home directories

Terminal

rsync -av /mnt/oldsystem/home/ /home/

Database files

Terminal

systemctl stop mariadb # or: systemctl stop mysql rsync -av /mnt/oldsystem/var/lib/mysql/ /var/lib/mysql/ chown -R mysql:mysql /var/lib/mysql

Only copy MySQL data files if both servers run the same MySQL/MariaDB version. For different versions, use mysqldump instead.

Step 6: Carry over users and SSH keys

Transfer system users, passwords, and SSH keys from the old server.

Terminal

cp /mnt/oldsystem/etc/passwd /etc/passwd.alt cp /mnt/oldsystem/etc/shadow /etc/shadow.alt rsync -av /mnt/oldsystem/root/.ssh/ /root/.ssh/ chmod 700 /root/.ssh chmod 600 /root/.ssh/authorized_keys

Step 7: Transfer cron jobs

Copy scheduled tasks from the old system.

Terminal

cat /mnt/oldsystem/var/spool/cron/crontabs/root cp /mnt/oldsystem/etc/cron.d/* /etc/cron.d/

Step 8: Unmount and clean up

Cleanly unmount the drive after migration.

Terminal

umount /mnt/oldsystem

For RAID setups additionally:

Terminal

mdadm --stop /dev/md0

Need help with the drive swap?

The physical installation of drives in our data centre must be carried out by our technical staff. Open a support ticket in the PowerPanel.

Open a Support Ticket