Quickly create a (swap)file on linux

The traditional way for creating a linux swapfile would be using dd to create an empty file e.g. A faster way is to use “fallocate” e.g. 1) http://www.cyberciti.biz/faq/ubuntu-linux-create-add-swap-file/ Don’t forget the usually procedure for swapfiles: References   [ + ] 1. ↑ http://www.cyberciti.biz/faq/ubuntu-linux-create-add-swap-file/

Moving to KVM

Since our beloved OpenVZ virutalisation technology is not moving in a direction we are comfortable with, we are currently evaluation several virtualisation technologies. One the the possible options is KVM. This is not a full tutorial about KVM, there are many good tutorials already, e.g. 1)https://www.lisenet.com/2016/getting-started-with-kvm-on-debian-jessie/ or 2)http://linuxnewbieguide.org/?p=1993 or 3)http://xmodulo.com/use-kvm-command-line-debian-ubuntu.html or 4)http://wiki.libvirt.org/page/UbuntuKVMWalkthrough or 5)http://www.cyberciti.biz/faq/how-to-install-kvm-on-ubuntu-linux-14-04/, this […]

Running “backticks” commands on remote servers

Sometimes it’s necessary to run a complex command on a remote server witch also includes some “backticks”. Usually these commands are interpreted by the local shell so you need to use a little trick to force execution on the remote server: ssh this.is.my.beautiful.server ‘( echo `echo “This Command is run on the remote server” ` […]

Update for the Checklist on “mailout” servers

This is an update to the checklist to create a prefect mailout server: Original Checklist Setup DMARC DNS Record to receive mail delivery reports https://www.unlocktheinbox.com/dmarcwizard/ btw: I Just started adding all those settings to my own domain too. Google DKIM signing is still waiting for DNS propagation.

Cloudflare and Haproxy Lodbalancer

We are currently trying out the cloudflare service to protect one of our company service. In front of this service we are using haproxy as SSL endpoint and loadbalancer. Cloudflare adds a number of custom headers1)http://www.linuxorz.com/2014/10/cloudflare-haproxy-get-real-ip/: In order to extract the original client IP in the X_FORWARDD_FOR header, you need to use the following configuration2)http://permalink.gmane.org/gmane.comp.web.haproxy/12019 […]

Java SSL Certificate Verification Error

If you come across the situation, that your java programs are not able to connect to ssl encrypted services, it might be most likely that the java cacerts keystore is empty or not uptodate. This might also be due to a bug in the java (or ca-certificate-java) package 1)https://bugs.launchpad.net/ubuntu/+source/ca-certificates-java/+bug/1396760. In order to fix the issue, […]

Hardening SSL

Update: 2014/01/17: Again a few weeks have past without finishing the article. So I’m going to publish it anyway even it it is unfinished work yet. I also disabled OCSP Stapling again. I’m using StartSSL and I’ve had some issues with their OCSP website. Also the nginx implementation is still not “mature” (see: http://nginx.org/patches/attic/ocsp-stapling/README.txt). There […]