Monthly Archives: March 2016

Shrink sparse cqow2 disc image

There might be cases when a VM temporarily¬†used a lot of disk space which is then not needed any more. The sparse disk image format qcow2 will grow as the disk space is used, but it does not automatically shrink. … Continue reading

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Perform a portscan using netcat

To perform a port scan, most of the time we think about a separate program. Sometimes it is not necessary to look that far. On most Linux systems netcat is already installed or can be installed easily from a repository. Continue reading

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Restrict SSH access to port forwarding to one specific port

Allowing access to an unprotected service on a server is always a problem. Sometimes the easiest way is to not expose this service to the network but allow access via ssh port-forwarding, but how to limit the SSH account to … Continue reading

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