Category: System Administration

Using fail2ban to mitigate simple DOS attacks against apache (or why I am a terrible sysop)

   Sam Nicholls    No Comments yet    Devops, System Administration

Earlier this afternoon, my server was upset. Here’s what happened, how it took so long to find out, and how I will try and stop it happening again. In particular, I provide configuration for a `fail2ban` jail to try and stop simple DOS, that actually works.


How to switch SATA controller driver from RAID to AHCI on Windows 10 without a reinstall

   Sam Nicholls    No Comments yet    System Administration

I was bemused to find a Linux live disk unable to identify the storage volume on my new Dell XPS 13 laptop. It seemed I needed to change the SATA controller mode from `RAID` to `AHCI`, but Windows had other ideas. Unable to find a solution online that didn’t cause a boot BSOD, I found my own.


  

`memblame`

   Sam Nicholls    No Comments yet    System Administration, Tools

As a curious and nosy individual who likes to know everything, I wrote a script dubbed memblame which is responsible for naming and shaming authors of “inefficient”1 jobs at our cluster here in IBERS. It takes time, often days, sometimes longer, of patience to see large-input jobs executed on a node on the compute cluster […]