#Server Migration
Egress Firewall Breaks Domain Checks — Tests as root Pass
The domain order page reported every name as unavailable, even names I made up. The cause was an outbound DROP policy with port 43 missing from the allowed port list after an operating system migration. The trap was that tests as root passed every time. Testing must use the account that actually runs the app.
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.
Rebuilding DirectAdmin Backups with NFS and POSIX ACL in Production
A record of rebuilding backups on a DirectAdmin server after migrating to a new machine — from FTP push that broke at three layers to an NFSv4 hard mount + POSIX ACL, with kernel-level lessons learned along the way.
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 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.