Monday, 24 July 2017

Using screen with UNIX/Linux

Using screen with UNIX/Linux

One wise sysadmin trick is to always type "screen" as soon as you log into any remote system. The reason being that if you need to come back to something, a long download or file transfer for example, then you can always detach the screen session, log out, and come back later. The session will remain open and whatever you were doing will keep running.
I recently downloaded a large backup file from a far away, remote server on a slow connection. Thanks to screen I was able to start the transfer from the far remote system to another, nearby remote system and then logout. I could then login periodically to that system, reattach the screen session, look at the progress, and detach it again and log back out. I was also able to do this multiple times, from multiple systems. It's a super handy tool and something every Linux user should know how to use.
https://www.tecmint.com/screen-command-examples-to-manage-linux-terminals/

Friday, 21 July 2017

Advanced Linux - using TCP BBR

Advanced Linux - using TCP BBR

I've looked at BBR and it certainly looks like a great innovation in network performance. That said I only recommend its use right now by advanced Linux admins with a pressing need for the improved performance, and then only after serious load testing on non critical network links.
For everyone else I recommend you wait until it is integrated into your Linux distribution and the mainline kernel. That way you are not messing with your vendor's highly tuned and optimized kernel configuration and you're getting something tested and integrated into the system as a whole.

#Linux #SysAdmin #Networking
https://www.cyberciti.biz/cloud-computing/increase-your-linux-server-internet-speed-with-tcp-bbr-congestion-control/

Wednesday, 5 July 2017

Watch out for security patches for anything you use that uses GnuPG's crypto library!

Watch out for security patches for anything you use that uses GnuPG's crypto library!

That may actually be more things than you think. Things like routers, phones or phone apps, etc. and not just on Linux. GnuPG is widely used cross platform.

#linux #Security #SysAdmin #Windows
http://www.theregister.co.uk/2017/07/04/gnupg_crypto_library_cracked_look_for_patches/

Saturday, 17 June 2017

OpenSUSE ups the security game in Tumbleweed with PIE support enabled as the default for all binaries

OpenSUSE ups the security game in Tumbleweed with PIE support enabled as the default for all binaries

FTA:
"Tumbleweed is now built with PIE (Position Independent Executables) as default. [...] This allows full ASLR (address space randomization) for all binaries without specific need to change your actual package, making attacks much harder,"

#Linux #Security #OpenSUSE
http://news.softpedia.com/news/opensuse-tumbleweed-os-is-now-built-with-pie-as-default-for-increased-security-516527.shtml?utm_content=buffer68f37&utm_medium=social&utm_source=plus.google.com&utm_campaign=buffer

Tuesday, 13 June 2017

Linux Tips & Tricks - Listing installed repositories

Linux Tips & Tricks - Listing installed repositories

This is a simple but handy thing to know. This page will show you how to list what software repositories are installed on your Linux system. Instruction are given for each of the major package managers.

When might you use this? Well for one it's common to go looking for an application to accomplish a certain task and in reading through forums and whatever you come across something like "Oh yeah, I use for that. It's in the so just install it from there." OK, but how do you know if you have installed? Well, here's your answer. ;')

https://www.ostechnix.com/find-list-installed-repositories-commandline-linux/

Friday, 2 June 2017

Monitoring hard drive health in Linux

Monitoring hard drive health in Linux

Using and setting up tools like smartd are essential sysadmin skills, particularly setting up e-mail notifications. However, smartd is simple enough to setup that home users should consider using it too.

https://www.cyberciti.biz/tips/linux-find-out-if-harddisk-failing.html

Saturday, 27 May 2017

Linux Tips & Tricks - Using alias

Linux Tips & Tricks - Using alias

While alias is a great way to shorten commonly used commands, I rarely recommend that people do so. Why? Because those alias' won't be on any other system you might use and it's easy to forget the syntax of the original commands they replaced. I especially don't recommend this for consultants and admins that work on a lot of other systems for this reason. It becomes a crutch that you will not have anywhere but on your machines.
However, I've posted this anyway because there are certainly cases where it's very useful. Just be careful to use them sparingly, only where necessary, and only on systems that you use constantly.

#Linux
https://opensource.com/article/17/5/introduction-alias-command-line-tool