Losing website server content is one of the most serious issues facing operations personnel. Database loss can occur for a variety of reasons, but regardless of the cause, quickly and effectively restoring website data is crucial. The first step in data recovery is to immediately stop writing to the affected storage device. Continuing to write new data could overwrite deleted files, resulting in permanent data loss. If the server is still running, the website should be switched to maintenance mode or a backup server as soon as possible to prevent users from accessing the abnormally active service.

Checking available backups is the first step in data recovery. Any professional server deployment should have a regular backup strategy. Common backup types include full, incremental, and differential backups. You can use the following command to check the existence and integrity of backup files:

# Check the most recent backup file
ls -la /backup/website/
# Verify the integrity of the backup archive
tar -tf /backup/website/backup-2024-10-01.tar.gz

If you use a database-driven website (such as WordPress or Drupal), you will need to restore both the file system and the database. You can restore a MySQL database using the following command:

# Restore a MySQL database
mysql -u username -p database_name < /backup/website/db_backup.sql

For a PostgreSQL database, the restore command is slightly different:

# Restore a PostgreSQL database
pg_restore -U username -d database_name /backup/website/db_backup.dump

When no backup is available, you need to attempt to restore data from the file system. On an EXT4 file system, you can use the extundelete tool to attempt to recover deleted files:

# Install extundelete
sudo apt-get install extundelete
# Restore all deleted files on a partition
extundelete /dev/sda1 --restore-all

For an XFS file system, you can use the xfs_undelete tool:

# Attempt to recover files on an XFS file system
xfs_undelete /dev/sdb1 -o /recovered_files

If the server uses LVM logical volume management, snapshot functionality may be available. Even if no snapshots are explicitly created, some systems are configured for automatic snapshots:

# Check for available LVM snapshots
lvdisplay
# Mount the snapshot volume for data recovery
mount /dev/vg0/website-snapshot /mnt/snapshot

Web server web logs and database logs may also contain useful information. Apache and Nginx access logs may record past content requests. While they cannot directly restore the content, they can provide clues for content reconstruction:

# Analyze recently accessed URL paths
grep "GET /important-page" /var/log/nginx/access.log

The database binary log, if enabled, can be used to redo data changes:

# Use the mysqlbinlog tool to process the binary log
mysqlbinlog /var/log/mysql/mysql-bin.000001 | mysql -u root -p

Revision control systems are another recovery option. If your website's content is managed using a version control system like Git, you can re-pull the code and content from the remote repository:

# Re-clone content from a Git repository
git clone https://github.com/username/website.git /var/www/html

For websites using a content management system (CMS), you can sometimes restore content using the CMS's auto-save or version history features. For example, WordPress automatically saves post revisions:

sql
-- Query WordPress post revisions
SELECT * FROM wp_posts WHERE post_parent = [ID] AND post_type = 'revision';

Cloud environments and virtualization platforms often provide additional recovery options. If the server is running on a virtualization platform such as VMware, Hyper-V, or KVM, virtual machine snapshots may be available:

# List available virtual machine snapshots
virsh snapshot-list webserver

Cloud service providers often offer disk snapshot functionality, which can be used to restore an entire disk to a previous state:

aws ec2 create-volume --snapshot-id snap-0123456789 --availability-zone us-east-1a

In some cases, professional data recovery services or tools may be necessary. When a file system is severely damaged or overwritten, tools such as TestDisk and PhotoRec can attempt to recover data:

# Analyze the partition using TestDisk
testdisk /dev/sda
# Recover a file using PhotoRec
photorec /dev/sda1

After data recovery is complete, a thorough verification must be performed to ensure that the recovered data is complete and consistent:

# Check the integrity of the recovered file

find /var/www/html -type f -exec md5sum {} \; > /tmp/recovered_checksums.txt

# Compare the checksums with the backup
diff /tmp/backup_checksums.txt /tmp/recovered_checksums.txt

To prevent future data loss, establish a comprehensive backup and monitoring strategy. Implement the 3-2-1 backup principle: maintain at least three copies of your data on two different media, with one copy stored offline. Regularly test your backup and recovery procedures to ensure they work properly when needed.

Response to a data loss incident should also include a post-mortem analysis to determine the root cause and implement preventative measures. This may include improving operational procedures, strengthening permissions management, or implementing technical measures to prevent accidental deletion.

Web server data recovery is a stressful and time-sensitive process, but with a systematic approach and the right tools, most data loss scenarios can be effectively resolved. The key is to remain calm, follow the planned recovery process, and adhere to good backup practices in daily operations.