Shore Up
Ketan AagjaDirector of IT · 22+ years in infrastructure, security & mail systems

Runs enterprise networks and security for a living, and writes Shore Up to turn two decades of hands-on Linux, Windows and mail-server work into guides you can actually use.

Security

Factory Reset and Recover a SonicWall with SafeMode

SafeMode is SonicWall's out-of-band recovery boot. You enter it with the physical reset button, and from a small web page on the appliance you can reboot the current firmware, boot a backup image, upload firmware, export settings, or boot with factory default settings — which wipes the running configuration back to out-of-the-box defaults. This guide covers using SafeMode to factory reset and recover a firewall you're locked out of, or one whose config or firmware is corrupt.

6 min read
Linux

Automatically Restart a Hung Service on a Schedule, with Logging

Some services don't crash cleanly. The process stays alive, systemctl still calls it active , but it has stopped answering — a wedged worker pool, a deadlocked thread, a leaked connection table. systemd's own Restart=on-failure handles a process that exits , but it won't help you with one that's technically running and doing nothing. This guide sets up a periodic health check that catches that case, restarts the unit when it's genuinely stuck, and logs every decision so you can prove what happened at 3 a.m.

8 min read
LinuxMail

Automate DKIM Key Checks and Rotation on OpenDKIM

This guide has two parts. The check part is a read-only script that queries DNS for your published DKIM record and confirms it still matches the private key OpenDKIM signs with — safe to run any time, and safe to put on cron. The renewal part generates a new key under a new selector, has you publish a DNS record, and then switches signing over to it.

9 min read
Security

Set Up Content Filtering (CFS) on a SonicWall

This guide turns on SonicWall's Content Filtering Service (CFS): the firewall inspects outbound HTTP/HTTPS requests, looks the destination category up against SonicWall's cloud database, and blocks or allows the request based on a profile you define. The purpose is category-based web filtering for a specific zone (typically your LAN).

6 min read
Windows

Batch-Rename Files by Pattern with a Windows Batch Script

This is a cmd.exe batch file that renames files in one folder by find-and-replace: it takes every file matching a mask (say *.txt ), swaps a substring in the filename (say draft → final ), and renames it. Its purpose is bulk cleanup of filenames — removing a stray word, fixing a prefix, changing a spelling — without you clicking through Explorer.

7 min read
Linux

Scheduled Database and File Backups to S3-Compatible Storage with rclone

This sets up an unattended nightly job that dumps your MySQL/MariaDB databases and tars up a couple of directories, uploads both to an S3-compatible bucket with rclone , and then deletes backups in that bucket older than a retention window. Its purpose is a hands-off off-site copy that prunes itself so the bucket doesn't grow forever.

8 min read
Security

Configure High Availability on a SonicWall Pair

This guide pairs two identical SonicWall appliances into an Active/Standby High Availability cluster: the Primary handles all traffic, the Secondary sits synchronized and idle, and if the Primary fails the Secondary takes over the firewall's identity and keeps traffic flowing. That is the whole purpose — surviving a hardware failure without hand-rebuilding a box.

6 min read
WindowsSecurity

Automate DNS Record Audits on Windows DNS with PowerShell

This guide builds a read-only audit of a Microsoft DNS server: it enumerates the zones, exports every resource record to CSV, and produces a short report of records that look stale (dynamic records whose aging timestamp is older than a threshold you set). The audit script itself creates nothing and deletes nothing — its worst case is a CSV file on disk.

9 min read
Linux

Automate Container Image Cleanup on a Docker Host

Docker hosts fill up quietly. Every docker pull , every CI build, every image rebuild leaves layers behind, and /var/lib/docker grows until a deploy fails with "no space left on device" at the worst possible moment. This guide sets up a scheduled job that prunes unused images older than a threshold you choose, so the host reclaims space on its own without you babysitting it.

9 min read
Security

Back Up and Restore SonicWall Settings and Firmware Safely

This guide covers two related jobs on a SonicWall firewall: taking a full backup of the running configuration (and creating a restore point), and upgrading or rolling back firmware. The purpose is simple — never touch firmware or a risky rule change without a known-good copy you can boot back to.

6 min read
Windows

Generate a Disk-Space Report Across Servers with PowerShell Remoting

This guide builds a read-only disk-space report. It uses PowerShell remoting ( Invoke-Command over WinRM) to query each server's local fixed disks and returns size, free space, and percent free as one combined table you can export to CSV or HTML. It does not write to, resize, or clean up any disk — it only reads WMI/CIM data.

10 min read
LinuxSecurity

Audit World-Writable Files and SUID Binaries with Bash

This script reads your filesystem and reports two classes of risky files: world-writable files and directories (anyone on the box can modify them) and SUID/SGID binaries (they run with the owner's or group's privileges, often root). It writes a timestamped report and, optionally, a baseline you can diff against later. It does not change any permissions, delete anything, or modify a single file — it only runs find and writes a text report to a directory you choose.

9 min read