#Debian
The Service Is Running but Dead — systemd restart Cannot Help
A long network outage broke DNS. A daemon holding a session with an external API failed to log in 194 times, then hung halfway through the process. It never exited, so the system never restarted it — why I stopped checking whether a process was alive and started measuring data freshness instead.
Tell a Broken Link from an ISP Outage Before Restarting Anything
A typical watchdog restarts NetworkManager when ping fails, which is wrong half the time because no internet access may mean the ISP is down, not that the adapter has failed. This article distinguishes three states using nmcli, then escalates from gentle recovery to PCI remove and rescan without rebooting the machine.
Every File Is Backed Up, but I Still Can't Rebuild the Server
The database dump is complete, the code tar is complete, and all the secrets are there, but put them on a blank machine and the site will not come up, because the things that actually make the server work were never in the backup files. This article lists what disappears with the machine and the recovery sequence I wrote for my future self.
Backups Succeeded Nightly, but Offsite Uploads Failed for 3 Weeks
cron ran every night, local files were complete every day, and the log said done, but offsite storage had not changed for 3 weeks. The first 8 nights of backups were already gone for good because local rotation had deleted them first. This article examines the two gaps that let the failure stay silent for so long.
MariaDB on defaults — a 128M buffer pool on a 55 GB RAM server
A 16 core server with 55 GB RAM and an SSD, but MariaDB still had the default 128 MB buffer pool. The result was 50 million disk reads in 5 days. The full before-and-after settings, service name and config path traps on DirectAdmin/Debian, rollback steps, and another 500 MyISAM tables waiting for conversion.
Read-only Debian shared-host security audit — avoid banning yourself
Audit the security of a Debian server running DirectAdmin in read-only mode first — but the first trap is that scan traffic itself triggers CSF's brute-force rules and gets your own IP banned. This article lays out a safe audit sequence + areas to check in 2024-2026
Legacy Apps Break After Migration — MariaDB Strict Mode Errors
After moving a website from an old server to a new one, the registration form breaks even though the code has not changed — the cause is STRICT_TRANS_TABLES in the sql_mode of newer MariaDB versions, with fixes at 3 levels, from conf.d to per-app SET SESSION
Using Claude to Upgrade Proxmox 8 to 9 and Rebuild Windows VMs
A real case using VS Code + Claude to upgrade an entire Proxmox cluster from 8 to 9, then delete and rebuild all Windows VMs for VDI without ever SSHing into a host myself. I have laid out the commands and scripts Claude generated during the actual work as steps that a person or AI can read and run again.
qcow2 or ZFS — Why I Switched After 12 Years on the Same Server
The reasons behind my storage choices for a Proxmox server that has run for 12 years without a reinstall — why I chose qcow2 in 2014, why I only moved to ZFS in 2026, and what actually changed the calculus.
DirectAdmin from CentOS 7 to Debian 12 on Proxmox (Series Index)
Notes on migrating a DirectAdmin shared host from CentOS 7 (EOL) to Debian 12 on Proxmox, serving 80+ customers, split into 5 parts with an overview of the process and links to every part
Moving DA from CentOS 7 to Debian 12, Part 4 — Cutover and 17 Issues
The actual cutover, where the near-0 downtime plan fell apart because of the DA Legacy license and slow qcow2 reads, ended with 1 hour of downtime and 17 issues in quick succession after the switch — critical web stack outages, medium issues affecting subsets of services, and minor debugging notes.
DA Migration Part 3 — DirectAdmin + CustomBuild on Debian 12
Installing DirectAdmin through setup.sh, then assembling a stack with multiple PHP versions, MariaDB, ModSecurity, and rspamd using CustomBuild on a staging VM behind NAT, including pitfalls I ran into myself.
Moving DA to Debian 12, Part 2 — Switching Storage to a ZFS Mirror
Replace the three storage layers of mdadm RAID1 + ext4 + qcow2 with a single layer of ZFS mirror + raw zvol while the old VM stays online, by degrading RAID to a single disk.
DA CentOS 7 → Debian 12 on Proxmox Part 1 — NAT pre-stage
Preparing a new VM on an internal bridge with NAT while the old VM continues serving customers, reducing downtime when migrating DirectAdmin from CentOS 7 to Debian 12 on Proxmox.