sBlock - Backup on RHEL, CentOS, AlmaLinux & Rocky Linux

This guide will walk you through setting up a backup system on your Red Hat Enterprise Linux (RHEL), CentOS (including CentOS 7 and CentOS Stream), AlmaLinux, or Rocky Linux server using our block storage, which communicates via the iSCSI protocol. The steps are identical across these distributions.

Prerequisites

• A server running RHEL, CentOS, AlmaLinux, or Rocky Linux with root or sudo privileges.
• Access to your iSCSI sblock storage target.
• The iscsi-initiator-utils package installed.

Step 1: Install the iSCSI Initiator

First, install the required package:

sudo dnf install iscsi-initiator-utils -y

For CentOS 7, use yum instead:

sudo yum install iscsi-initiator-utils -y

Enable and start the iSCSI service:

sudo systemctl enable --now iscsid

Step 2: Discover Available iSCSI Targets

Use the following command to discover the iSCSI storage target. Replace [Your_iSCSI_Target_IP] with your actual iSCSI target address.

sudo iscsiadm -m discovery -t sendtargets -p [Your_iSCSI_Target_IP]

Step 3: Log in to the iSCSI Target

Once the target is discovered, log in:

sudo iscsiadm -m node -T [Target_Name] -p [Your_iSCSI_Target_IP] --login

To make the login persistent across reboots:

sudo iscsiadm -m node -T [Target_Name] -p [Your_iSCSI_Target_IP] --op update -n node.startup -v automatic

Step 4: Verify the Attached Disk

Check if the new block storage is available:

lsblk

Step 5: Format and Mount the Block Storage

Format the disk (replace /dev/sdX with your actual device name):

sudo mkfs.xfs /dev/sdX

Create a mount point and mount the disk:

sudo mkdir /mnt/blockstorage
sudo mount /dev/sdX /mnt/blockstorage

To make the mount persistent, add an entry to /etc/fstab:

echo "/dev/sdX /mnt/blockstorage xfs defaults 0 0" | sudo tee -a /etc/fstab

Step 6: Set Up Automated Backups

Option 1: Using rsync for File Backups

To back up files to the mounted block storage:

rsync -av --progress /path/to/source /mnt/blockstorage/backup/

To automate backups, add a cron job:

crontab -e

Add the following line to schedule a daily backup at 2 AM:

0 2 * * * rsync -av --delete /path/to/source /mnt/blockstorage/backup/

Option 2: Using tar for Archival Backups

Create a compressed backup archive:

tar -czvf /mnt/blockstorage/backup_$(date +%F).tar.gz /path/to/source

Option 3: Using BorgBackup for Efficient Backups

Install BorgBackup:

sudo dnf install borgbackup -y

For CentOS 7, first enable EPEL:

sudo yum install epel-release -y
sudo yum install borgbackup -y

Initialize a backup repository:

borg init --encryption=repokey /mnt/blockstorage/borg-repo

Backup data:

borg create --progress --stats /mnt/blockstorage/borg-repo::backup-$(date +%F) /path/to/source

Step 7: Verify and Restore Backups

For rsync Backups

To restore files:

rsync -av /mnt/blockstorage/backup/ /restore/path/

For tar Archives

Extract backup files:

tar -xzvf /mnt/blockstorage/backup_YYYY-MM-DD.tar.gz -C /restore/path/

For BorgBackup Archives

Restore the latest backup:

borg extract /mnt/blockstorage/borg-repo::backup-$(date +%F) --target /restore/path/

Conclusion

You have successfully set up block storage on RHEL, CentOS, AlmaLinux, or Rocky Linux and configured an automated backup solution using iSCSI.