The latest version of the openSSH server/client has just landed for both Ubuntu 7.10 and 8.04 and this has generated some problems with our local network. Namely our public/private keys that we use for password-less access between our development machines, turns out the keys were generated using a version of openSSL that had a faulty random number generator which made the keys not really random at all 
Upon update you’ll probably see a message box with something like the following if this applies to you.
Some of the OpenSSH server host keys on this system were generated with a version of OpenSSL that had a broken random number generator. As a result, these host keys are from a well-known set, are subject to brute-force attacks, and must be regenerated.
Users of this system should be informed of this change, as they will be prompted about the host key change the next time they log in. Use ‘ssh-keygen -l -f HOST_KEY_FILE’ after the upgrade has changed to print the fingerprints of the new host keys.
The affected host keys are:
/etc/ssh/ssh_host_rsa_key /etc/ssh/ssh_host_dsa_key
User keys may also be affected by this problem. The ‘ssh-vulnkey’ command may be used as a partial test for this. See /usr/share/doc/openssh-server/README.compromised-keys.gz for more details.
The solution was simply to regenerate our keys and push them out to all the boxes that we wanted to be able to log into to… time consuming but ultimately giving us a more secure environment.
Just realised that NFS support is (somehow) not included out of the box with 7.10 so when I added an NFS mount to my fstab like so
192.168.xx.xx:/bigraid/sunshine /sunshine nfs user
and then attempted to mount with “sudo mount /sunshine”, I got an error as follows
mount: wrong fs type, bad option, bad superblock on 192.168.xx.xx:/bigraid/sunshine,
missing codepage or helper program, or other error
(for several filesystems (e.g. nfs, cifs) you might
need a /sbin/mount. helper program)
In some cases useful info is found in syslog - try
dmesg | tail or so
The solution was as simple as
sudo apt-get install nfs-common
I’m running ubuntu linux as my main OS with a windows XP VM for all those things I just have to have windows for (like writing plugins for a must have application). The problem I sometimes have with this is that disk accesss can be terrible from inside the VM, like cleaning up 20 odd Gb of data that were cluttering up the disk image – thankfully if you shut down the VM you are able to mount the disk image natively and perform operations on it.
sudo mkdir /mnt/winxp_one
sudo vmware-mount.pl /var/vm/WinXP_One/Windows\ XP\ Professional.vmdk 1 /mnt/winxp_one/
And then suddenly I can navigate my C drive from that mount point and delete that 20Gb of files in 20 seconds instead of 20 minutes like it would have been under windows.
[dev@stoner:/mnt/winxp_one/BDK] ls ../
AUTOEXEC.BAT CONFIG.SYS MSDOS.SYS pagefile.sys ruby
BDK Documents and Settings NTDETECT.COM PDOXUSRS.NET System Volume Information
boot.ini dump.txt ntldr Program Files temp
Config.Msi IO.SYS OT RECYCLER WINDOWS
[dev@stoner:/mnt/winxp_one/BDK]
However, I did have to manually kill the process after I had finished in order to release the lock on the vmdk file
[dev@stoner:/mnt] ps -e | grep vm
6121 ? 00:00:00 vmnet-bridge
6143 ? 00:00:00 vmnet-netifup
6144 ? 00:00:00 vmnet-netifup
6163 ? 00:00:00 vmnet-natd
6170 ? 00:00:49 vmware-serverd
6191 ? 00:00:00 vmnet-dhcpd
6192 ? 00:00:00 vmnet-dhcpd
8049 pts/2 00:00:00 vmware-mount.pl
8059 pts/2 00:00:04 vmware-loop
8060 pts/2 00:00:00 vmware-loop
[dev@stoner:/mnt] sudo kill -9 8049 8059 8060
Just upgraded my home system to the latest Ubuntu distro and had a bit of a strange problem while fiddling with my xorg.conf. I accidently overwrote the file using dexconf and suddenly my screen resolution options dialog only had 800×600 and 640×480 as the available options. Given that I have 23″ widescreen that is capable of 1600×1050 this is rather distressing, especially when I edited my xorg file and still couldn’t get any more options to appear, this is (I think) caused by the changes to X in hardy heron which aim to make it easier to configure. Luckily I found a solution by re-installing the nvidia driver using envy
sudo apt-get install envyng-gtk
sudo apt-get install nvidia-settings
envyng -g
Then follow onscreen instructions, reboot and then run
nvidia-settings
where I was finally able to select an appropriate resolution.
I didn’t think it was going to be possible but this guy found a way for me to at least get the server console running so that I can connect to my machine at work!!
Basically the solution was to move vmware versions of libgcc and libpng out of the way
cd /usr/lib/vmware-server-console/lib/libgcc_s.so.1
mv libgcc_s.so.1 libgcc_s.so.1.org
cd ../libpng12.so.0
mv libpng12.so.0 libpng12.so.0.org
So I was building a machine for my mother for her medical practice… nothing fancy just a regular sit-out-back headless server that she can have chugging away co-ordinating her office while the prettier looking machines get stuck out front for patients to see. Well while building it I noticed that she didn’t really require 500Gb of hard drive, 320Gb would be fine for her needs and luck just happened to have it that I had a spare 320Gb hanging around and a hankering for a 500Gb drive in my new desktop. A deal was made and my time was given over in return for a hard drive upgrade, I would install ubuntu on the new 500Gb drive, copy data over from the old one and then install windows XP on the 320Gb for her to install her new software packages on.
This all went swimmingly after I realised that the old 320 was formatted with Logical Volume Management (LVM) partitions and that I needed to install the LVM2 tools and then restart my new machine (thanks Fedora).
sudo apt-get install lvm2
So after finally realising that a reboot was required (I guess I’m spoilt by never having to restart normally), I finally managed to get the required data off the HD and onto the new 500. Phew…. problems over right? wrong!! When I built the new system and tried to install windows XP I got a rude shock… the cd-rom didn’t seem to like the boot cd and wouldn’t get any further than
Setup is inspecting your computers hardware... this may take a few minutes
Well I left that thing for hours and no joy it was most definitely hanging and was not about to progress any further, luckily being the technophile that I am I had a spare cd-rom (or 5) lying around and I swapped each and every one of those units in to no effect. Maybe the memory got buggered? memcheck passed! Maybe it’s the cd itself? Got a spare install media from work same edition, still no joy! Hmmm, where to next? Google! Turns out windows XP doesn’t play well LVM and in fact having an LVM partitioned hard drive in there will cause the entire process to summarily seize up!
The solution I ended up going with was to take an Ubuntu 7.10 live CD, start up and then use fdisk to remove all partitions on the disk and then “create a new empty DOS partition table”.
sudo fdisk /dev/sda
d 1 # delete partition 1
d 2 # delete partition 2
o # create a new empty DOS partition table
v # verify the partition table
w #write table to disk and exit
restart with the windows XP cd in the drive and things went perfectly… so kids the moral of the story is that, like gasoline and matches, Windows XP and LVM DO NOT MIX!!!
Was looking through the GUI options for a virtual machine I have and could not for the life of me figure out how to resize the hard disk. I originally thought that 10Gb would be sufficient for my windows image but that notion was quickly disabused after I’d installed Visual Studio and pulled down some data to work with. It would seem a fairly simple thing to do (memory and number of cpus allocated can be easily changed as long as the image is not currently running) but alas it would appear that you are stuck with what you originally budgeted for … if you are stuck in the GUI anyways.
The solution, as always involved a bit of command line magic. I store my images under /var/vm and the magic command was actually quite straight forward:
vmware-vdiskmanager -x 20GB /var/vm/WinXP/Windows\ XP\ Professional.vmdk
and voila after I’d restarted the vmware server console and rebooted the image there was 20Gb of space available!!! But wait…. the windows drive is only using 10Gb of it, how to get it using the whole thing. In the end our sysadmin came over with an Acronis Imager boot disk and we booted the image and quickly pulled up the boot ordering menu, selected “boot from cd” and then used the Acronis application for resizing a partition to use unallocated space. Reboot once more and then we were finally done!!
