ssh – select * from depesz;

Reconnecting to SSH servers

In my work I'm often in situation where I want to restart remote server, and then immediately connect to it over ssh.

This can be done by repeating ssh HOST in shell, but it gets tedious.

Continue reading Reconnecting to SSH servers

Why I like tmux?

For those of you that don't know – Tmux is program similar to screen, but written from scratch, with different functionality, approach, and capabilities.

I would like to show one particular case where I found that Tmux does something that screen doesn't.

Continue reading Why I like tmux?

OmniPITR 0.5.0

Today, I released new version of OmniPITR – 0.5.0.

This new version has one important new feature – which is so called “direct destination" for backups.

What it means? What it does? How it helps? Let's see…

Continue reading OmniPITR 0.5.0

A tale of slow ssh connections

At home I have couple of machines, but one of them takes relatively long time to login to.

It looks like this:

=$ time ssh blob id -u
1000
 
real    0m0.401s
user    0m0.010s
sys     0m0.000s

While 0.4s is not very long, it bugged me. And today, I decided to look into it, to see what's happening.

Continue reading A tale of slow ssh connections

Slow vim startup

I had today a very weird situation.

From my laptop, I ssh to another system, and from there to yet another.

On this final system I noticed that vim starts relatively slow. i.e. this command:

time vim -u /dev/null -c “:q"

returned time in around 3.5 seconds, while on my laptop (which is much less powerful) it is:

=> time vim -u /dev/null -c ":q"
 
real    0m0.073s
user    0m0.056s
sys     0m0.016s

I tried to debug the situation, and it got weirder. If I did “su – another_user" (on the final system) – it became fast. What's more: if I did su – depesz (my account) back – vim was still fast!

After some debugging it occurred to me: I have automatic X11 forwarding turned on. I checked – and yes, in the shell that vim starts slowly, i had “DISPLAY" variable, set to localhost:10.0!

Quick unset DISPLAY, and suddenly vim starts 0.027s!

Lesson for future – do not use automatic X11 forwarding for long-distance ssh connections, or make sure you run vim with “-X" option.

Later I learned why it tries X11 connection – to get access to X copy/paste buffer (available as * register). Nice feature, but with quite problematic side effects.

using separate environments for people using single account

there is this situation: multiple people have to have access to single system account on unix/linux.

you are one of them, but you really want to have your own environment. aliases, path, and so on.

problem? others dont want your changes. is it a lost case?

Continue reading using separate environments for people using single account

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Tag: ssh