#CentOS

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

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

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.

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.