(Links updated / last reviewed March 15, 2016)
- Freshly downloaded RHEL7 qcow2 KVM image to be a guest virtual system under KVM virtualization.
- Red Hat Enterprise Linux 6 as the host system running KVM virtualization.
- This is in review for Fedora Linux as a host system running KVM virtualization (this review is not completed)
You will find you need to change the password if you download a RHEL 7 kvm qcow2 image. This discussion goes into two different methods to do this. Make a note in the discussion area if you happen to have any suggestions etc...
Red Hat Enterprise Linux 7.x is now Generally Available (GA) (getting started guide) and available including in a qcow2 KVM image at the Red Hat Enterprise Linux product page (NOTE: a subscription is required, and this link is subject to change). The image is approximately 5 GB). You have to "root the system" after attaching it to a KVM session.
Download 7.2 KVM image at:
- Use this link to download 7.2 RHEL qcow2 image (link last checked 3/15/2016)
Method 1, Red Hat Documentation, Recovering Root Password (with grub 2)
Method 2 - Using "guestfish" to change the Password for the root account
You can use guestfish to edit a running system under KVM virtualization:
- You can use "guestfish" to edit the /etc/shadow file and change the root password.
- Guestfish is an interactive shell that you can use from the command line or from shell scripts to access guest virtual machine file systems. (See example below):
- If needed, first install the guestfish rpm.
- Red Hat Enterprise Linux 7.x (This command will not work on Fedora, If you are using Fedora Linux, see next block)
yum -y install guestfish
Thanks Ben Woodard from Red Hat FEDORA LINUX 20
# yum -y install libguestfs-tools
- Import the qcow2 image into KVM. The image will be named something along the lines of: "rhel-guest-image-7.1-20150224.0.x86_64.qcow2", (as of July 2nd, 2015, the version will of course change over time)
- Change the password on the newly imported KVM to get on the pre-built system.
Example steps to change the root password using guestfish:
- This set of instructions is for use on the host system that has the kvm RHEL 7 guest. The following is from Red Hat solution ID 641193
- The syntax is: guestfish --rw -a <image-name>
- (Note, your system may be /dev/vda1, mine was /dev/sda1. Use the 'list-filesystems' command)
root@box1 # guestfish --rw -a ./rhel-guest-image-7.1-20150224.0.x86_64.qcow2 ><fs> run ><fs> list-filesystems ><fs> mount /dev/sda1 / ><fs> vi /etc/shadow NOTE: after you perform the following steps you use "quit" to exit. DO NOT EXIT NOW, proceed with the following steps
- Replace the encrypted password (add it while you are still in vi).
This will set the password for the image permanently.
- An encrypted password can be created using the openssl command (see an example below).
NOTE: Open a separate terminal window to create an encrypted password with the openssl command (see example just below)
Separate window, different terminal window
[root@someothersystem ~]# openssl passwd -1 changeme $1$QiSwNHrs$uID6S6qOifSNZKzfXsmQG1
- There is a vi session open from the guestfish session mentioned above.
- Copy the output of the openssl command above and appropriately place it into the /etc/shadow file you have opened with vi.
When done type "quit"