Sometimes, especially during work in lab environments we need to stop all our instances ie. to avoid additional charges from cloud operator. Openstack offers a convenient way to do it – shelving. When you shelve an instance all machine’s volumes are saved but VM instance does not utilizing compute host resources. This state persists until you unshelve a specified machine. Openstack does not offer option to shelve/unshelve of all your instances at once, you need to do it on every machine separately. This simple bash script gives you an ability to shelve or unshelve all machines at once. Continue Reading
bash
All posts tagged bash
Suppose we have text with vowels. Vowels are special characters used in some languages to mark a special sound. Example with Polish characters:
$ echo "ąćęłńóśź" ąćęłńóśź
This short article describe how to reset lost root password on Linux system. IMPORTANT: This method require physical access to the machine.
On GRUB screen select normal boot option:
Press ‘e’ to edit selected option. You will see short GRUB code.
Search for the line starting with “linux /boot/vmlinuz…” or similar depending of Linux distribution. This is the place where kernel and rootfs is selected. Change ‘ro’ option to ‘rw’ and add: Continue Reading
Bash has ability of simple string manipulation. It has a various operators which allow do some basic text operations. This short article shows how to use these features in action with Bash.
Let’s say we have a variable text:
$ text="This is a sample text."