(Re)Installing without Immediate-Configure using Debian APT (via Awayand’s Blog)

This can also be done directly on the command line without changing the global APT config file with the following option (in my case to install imagemagick on testing):

# apt-get install imagemagick -o APT::Immediate-Configure=False

kopete wouldn't send anymore messages on msn. So I tried reinstalling using aptitude, selecting kopete, 'L', going to the "Depends" section and selecting 'L' there also. No dice, "E: Internal Error, Could not perform immediate configuration (2) on libstdc++6". So I added /etc/apt/apt.conf since it didn't exist, and added "APT::Immediate-Configure "false";". A little 'apt-config dump' confirmed the setting was active. After that, reinstalling work … Read More

via Awayand's Blog

Mount qcow2 (VM) images under Linux

If like me you find yourself screwing up a virtual machine Xorg configuration so badly that you can’t even switch to any virtual console anymore or, for whatever reason, you need to access the content of a qcow2 image from outside of the VM, most probably from the host, here is an easy way to do it thanks to qemu-nbd:

# modprobe nbd
# qemu-nbd -c /dev/nbd0 /path/to/image.qcow2

At this point we have loaded the Network Block Device kernel module and easily created and NBD device backed by our disk image thanks to the qemu-nbd program provided by qemu-kvm.

Now, we just have to identify tha partition(s) we’d like to mount and then mount it/them in the desired directory:

# fdisk -l /dev/nbd0
# mount /mnt/vmroot /dev/nbd0p3

You can now work in the image as in local filesystem !

Once you’re done, you need to unmount the partition, remove the device and unload the kernel module:

# umount /mnt/vmroot
# qemu-nbd -d /dev/nbd0
# rmmod nbd

Hope this little trick found here will help you like it did for me.

EDIT: If you happen to have I/O errors, try using ‘-n’ option of qemu-nbd which disables host cache (as suggested here).

Learn Linux, 302 (Mixed environments): Trivial Database files

Samba uses Trivial Database files to store both persistent and temporary data as part of its job integrating file and print sharing between Linux and Windows. In preparation for the Linux Professional Institute Certification exam LPI-302, learn all about the Samba Trivial Database (TDB) format that Samba uses to store information, how to look inside TDB files, and how to back them up.

via Learn Linux, 302 (Mixed environments): Trivial Database files.