Managing outdated backup files on remote servers is a common sysadmin task. While SCP and SFTP protocols weren't originally designed for complex file management operations, we can combine them with standard Unix tools to achieve our goal.

The most efficient approach is to use SSH in combination with the find command:

ssh user@remote.server "find /path/to/backups -type f -mtime +30 -delete"

Breakdown:
- -type f: Only target files (not directories)
- -mtime +30: Files modified more than 30 days ago
- -delete: Remove matching files

For environments where direct SSH access isn't available, we can use SFTP with a batch file:

#!/bin/bash
sftp -b - user@remote.server <
Then parse the output to identify old files and create a deletion script.
Here's a more robust script that handles edge cases:
#!/bin/bash
REMOTE_USER="user"
REMOTE_HOST="remote.server"
BACKUP_DIR="/path/to/backups"
DAYS_OLD=30

ssh ${REMOTE_USER}@${REMOTE_HOST} <
When automating file deletions:

Always test with -ls before using -delete
Consider implementing a dry-run mode first
Set proper permissions on backup directories
Log your deletion operations

For more complex scenarios, consider:

rsync with --remove-source-files flag
lftp with its mirroring capabilities
Ansible for orchestrated cleanup across multiple servers


When managing backups on remote servers, we often need to purge old files to save disk space. The tricky part comes when you only have SCP/SFTP access without direct shell access to the remote server.
Traditional methods like find -mtime +X -delete won't work here since we can't execute commands on the remote server. We need solutions that work purely through file transfer protocols.


lftp -e "mirror --only-newer --no-perms --no-umask --delete \

--verbose=3 /remote/path /local/path; quit" sftp://user:pass@host


This command will:

Connect via SFTP
Mirror only newer files
Delete older files from remote
Work without shell access

For more control, here's a Python script using Paramiko:


import paramiko

import time

from datetime import datetime, timedelta

ssh = paramiko.SSHClient()

ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

ssh.connect('hostname', username='user', password='pass')
sftp = ssh.open_sftp()

threshold = datetime.now() - timedelta(days=30)
for fileattr in sftp.listdir_attr('/backup/path'):

    if datetime.fromtimestamp(fileattr.st_mtime) < threshold:
        print(f"Deleting {fileattr.filename}")
        sftp.remove(f"/backup/path/{fileattr.filename}")

sftp.close()
ssh.close()

If you have rsync available:


rsync -avz --delete --files-from=<(ssh user@host 'find /backup -type f -mtime +30') \
empty/ user@host:/backup/

Always:

Test with --dry-run first
Backup before deletion
Use SSH keys instead of passwords
Limit script permissions