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Boot into the command line console in Ubuntu 16.04

As I just upgraded my 14.04 installation to 16.04, it booted right up to lightdm.

I had it properly setup to boot in a console before, but somehow it changed the behavior on me.

This is because the computer is now using systemd to boot.

I already had the GRUB variables setup as expected:

GRUB_CMDLINE_LINUX_DEFAULT="text"
GRUB_CMDLINE_LINUX="text"
GRUB_TERMINAL=console

But this is not enough if you want to start in the console when running systemd (which is running since 15.04).

systemd has a list of variables you can tweak using the systemctl command. To boot in ...

no talloc stackframe at ../source3/param/loadparm.c:4864, leaking memory

As I upgrade to 14.04, I started seeing this error in my console:

no talloc stackframe at ../source3/param/loadparm.c:4864, leaking memory

Quite cryptic if you ask me, but the "leaking memory" did sound bad.

The error would in particular appear when I used sudo for whatever reason, for example:

sudo iptables -L -nvx

So... something to do with sudo?

I found the answer on the Ubuntu forum. The solution is to turn off a feature of samba. Run the samba setup tool in your console:

sudo pam-auth-update

That opens a curses window in your console. You should then see an option ...

Testing your memory on a live Linux system

Today I wanted to test the memory on a remote server. I could not just reboot and run memtest86+ so instead I had to look for a different solution to testing most of the computer memory without having to reboot...

I found an interesting page in that regard describing a way to do so using md5sum on a very large file.

The is a verbatim copy of the Linux command line proposed.

  dd if=/dev/urandom bs=768304 of=/tmp/memtest count=1050
   md5sum /tmp/memtest; md5sum /tmp/memtest; md5sum /tmp/memtest

The size, 768304 is expected to be close to your memory size. You should know how much memory

Load Average, to know how busy your server is

Whenever you run many applications on a server, such as many instances of your web server (i.e. Apache), you may want to know how much of the system is being used. This can be important to avoid overloading your system.

The load is computed by the kernel. The kernel knows how many processes are running and how much processing power your server has (i.e. how many processors.) With that information, it infers how many processes are being held back for a period of time. The default periods are 1, 5 and 15 minutes (I'm sure you can recompile your kernel with different timings!)

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CVS and really large files

Yesterday, I got a nice little surprise...

I inadvertendly added two copies of an uncompressed MS-Access data in my CVS. The files were over 400Mb (about 434Mb if I'm correct.) This started okay, then slowly I could see my memory going banana.

Wow! It took a good 20min. to check-in. My CVS is on my computer, so it is not the transfer that's slow... The fact is, the allocated a buffer for the entire file! My computer was on its knees!

at job spool growing

How it works

The at command is often used to start a process at a later time. It can run any script at a specified date and time.

For instance, if you want the computer to send you a signal in one hour, use something like:

cat signal | at -q z now + 60 minutes

Assuming that the file named signal contains the commands necessary to generate the signal. Then in 60 minutes, the script will be execute and the signal will be heard or shown.

RETURN not working in Visual Basic & Arrays...

RETURN statement in BASIC

Like many programmers, I switch between languages quite often.

I have worked with BASIC before since I had an Apple //c and used other Apple ][ computers that had some (really bad, early) BASIC language in their ROM.

At the time, the worst part was the line numbers. You had to write in BASIC as if you were writing assembly language. And I'll skip the numerous problems with memory...

Enhanced DLLs

Pre-Pre-Scriptum: Please, look for the edll library. It is now available as a free library for MinGW.

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