We have a single machine that uses SELinux, because it has a needfor an unusually thorough level of security. This machine runsCentOS 7, because at the time we built this machine (several yearsago), CentOS 7 was the obvious long term support Linux to use toget a high security, SELinux based environment. Since CentOS haseffectively imploded, we are going to need to replace that machinewith some other distribution before the middle of 2024, and thedefault choice is Ubuntu.

If we

A while back I wrote about how large scale SSH brute force attacksseem to have stopped here . SSHisn't the only form of authentication that we have exposed to theInternet; we also have both an IMAP server and an authenticatedSMTP server, and unsurprisingly they also see activity. To mysurprise, the activity patterns are quite different (which tooksome time to discover, since they both actually authenticate throughDovecot).

Our authenticated SMTP server sees widespread and determined probesfrom a wide range of IP addresses that

Let's suppose that you have an inside network I on which you havea bunch of things used in your environment, like central syslogservers , your client mail gatewaymachine, and so on, and you also have an external machine E, thatyou would like to be able to use those services. One obvious seemingway that you could do this is by setting up some form of networktunnel between E and a touchdown machine T that has access to yourinside network I (these days you might use WireGuard

A while back I wrote about how free()s API means that (C) memoryallocation has to save some metadata , eitherexplicitly or implicitly, because you don't pass in the size ofwhat you're freeing. I happen to feel that this is still a decentAPI for C , but beyond that there's anotherlittle advantage to this API, which is that no one needs to knowhow big an allocated object is . There are at least three uses forthis.

The first use

USB, Thunderbolt, Displayport & docks ( via , also )is a high density 'overview' of the technology of all of these things,or at least the technology of the connectors and connections involved.Since it gets down to the level of the number of lines and lanes (andtheir speed) involved in USB signaling and so on, it's an overviewonly from a certain perspective.

Although I read it through once and absorbed some things, I think ofit more as a reference work that I

We've had a central syslog server for a longtime, and recently we've set up a Grafana Loki server as well, where we're sendingpretty much a duplicate of the logs that go to the syslog server.After using Loki for a while, I've come to the conclusion that thetwo serve different purposes and neither makes the other unnecessary.

(Grafana Loki is concisely called "Prometheus for logs", or to quoteits website it's 'a log aggregation system designed to

I last wrote about what Firefox addons I used back in the era ofFirefox 86, about a year and a half ago . I haven'twritten about this since then not because I don't care (addons areactually central to my Firefox experience), but because my sets ofaddons basically hasn't changed since then. There are multiplereasons for this; I try to be conservative about adding addons(partly because of past bad experiences with instability and memoryleaks), my needs and interests

If you start up the Prometheus host agent as root, it will nag atyou about this:

caller=node_exporter.go:185 level=warn msg="Node Exporter is running as root user. This exporter is designed to run as unprivileged user, root is not required."

This is not quite true, although how much it is and isn't true hasvaried over time, kernel versions, and also on what host agentinformation collectors you have enabled. Today, for my

One of the things happening here is that we're in the process of rolling over our Ubuntu 18.04 serverson to our current generations of server hardware as we rebuild them as Ubuntu 22.04based machines. This (and other local events) has caused us to takea look at what older servers we want to keep and what ones we wantto get rid of, or at least exile to the depths of the back shelves.Surprisingly, one factor is their CPU performance,