Fixing a broken Grub2 Bootloader after hard drive upgrade

13 11 2010

I recently replaced the hard drive in my laptop. I used Acronis True Image Home 2011 to clone the old hard drive to the new one. It increased the sizes of the partitions proportionatly and made the drive bootable. So far so good.

In addition to Windows 7 I have Ubuntu 10.10 dual booted using Grub2.

Windows 7 booted just fine after the upgrade but Ubuntu would not boot and dropped into busybox with the following error

/dev/disk/by-uuid/xxxx does not exist
dropping to shell

Where xxxx is a long number called a UUID

Because the Linux partition was now 20GB larger than before it had a new UUID which did not match what Ubuntu expected.  Since the introduction of Grub2 Ubuntu boots using Read the rest of this entry »


Ubuntu SMART disk analysis is slick!

26 12 2009

As soon as Ubuntu detects problems with a hard drive that reports S.M.A.R.T. diagnostics it pops up a warning and the depth of information is impressive. Speedfan has a nice enough analysis of hard drive health, but it is a little arcane. The Ubuntu utility really explains what is going on. It also shows historical ‘watermarks’ where a characteristic went over threshold in the past.

Here are some screen shots of what one can find about a hard drives health status.

Not surprisingly the failing hard drive was replaced and data backed up. Not one piece of user data was lost, as is often the case with failing hard drives, files affected are mostly system/program files. Recovery of data is typically very successful. In this case the user had only 700MB of data on a 500GB drive.

To look at the SMART characteristics of drives attached to an Ubuntu system start the Disk Utility which is located under
System -> Administration -> Disk Utility. This disk utility is a Gnome desktop tool, for those with other variants of linux or Ubuntu with different desktops it can be added to your distribution by installing the application gnome-disk-utility using synaptic package manager or the command line

sudo apt-get install gnome-disk-utility

Update 2010-11-14: Since the introduction of Ubuntu 10.4 the disk utility included in Ubuntu has changed. Screen shots of the new disk utility are included below. The utility provides more information, especially about how the disk partitions are organized. However I have found that once in a while the new utility reports that SMART disk statistics are unavailable for a disk, using Ubuntu 9.10 Live Disk reveals that the SMART statistics are available after all. This is an unfortunate problem with what is a great diagnostic tool, hopefully the drive compatibility will be improved back to its former glory.

Click to enlarge image

Click to enlarge image










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Fixing a failed update to Firefox in Ubuntu

19 12 2009

The problem

I did a routine update to one of my Ubuntu installations this morning, and lo and behold it failed during the Firefox update. Even after a cold reboot I was unable to start Firefox, it was broken.

Not able to browse the internet from Ubuntu to research the problem and never having had a problem like this before I was left with a conundrum. The update manager didn’t show Firefox as needing an update anymore. Eventually I stumbled on the fix, here it is.

The Fix

Launch Synaptic package manager and type in Firefox in the Quick search box. Find Firefox which should have a green check-box indicating it is installed. Right click the green Read the rest of this entry »

Best driver for Canon i475D on Ubuntu 9.10

18 12 2009

Ubuntu does not have a driver for the Canon i475D printer. I experimented with several and found that the ‘i450D foomatic/bjc800’ driver provided the best test page.

Some web resources (like this) suggest using the BJC800 driver, however I found it printed the test page very small on the page. I notice the i450 driver mentions the bjc800. Be sure to chose the i450/bjc800 and NOT the bjc800 only and the prints will be just fine.

Knoppix 6.2 Released – Departure from Swiss Army Knife Moniker

26 11 2009

A breath of new life has come to an old but faithful Linux distribution, Knoppix. Version 5.1.1 was released in January 2007 and 2 years later no further activity convinced me that Knoppix was a dead project, maybe Klaus Knopper had other things to occupy his time.

Fast forward to 2009 and we have seen 3 releases of Knoppix since February 2009 alone. The latest version 6.2 was released on November 18th 2009. Knoppix popularized the idea of a ‘Live CD’ where one could boot a computer to the CD without having to install anything on the hard drive. You could literally try before you committed to using it, or only use it for troubleshooting. It came with a large collection of free software which justly earned it the title of  a ‘Swiss Army Knife’ for computer enthusiasts and technicians. Other Linux distributions such as Suse and Ubuntu have also utilized the ‘Live CD’ delivery mechanism. What set Knoppix apart from other Linux distributions was its ability to automatically detect and configure for a systems hardware on the fly during boot-up, and it often got all devices working on systems I used it on. Other Linux distributions have followed suit and offer the hardware detection capability as well.

New Desktop

With Knoppix 6.0.1 released in February 2009, the KDE desktop was replaced with LXDE, a lightweight desktop environment. Many software packages were also absent from this version. Version 6.2 released November 2009 has further reduced the number of software packages included in the standard release. The Knoppix release notes indicate this is to encourage folks to re-master Knoppix adding tools specific to a need or purpose, such as computer forensics or educational tools etc. The good news is that the DVD version does include a large number of software packages, but even with the DVD version Kstars (Virtual Planetarium) and K3B (CD/DVD burner) are absent. Alternatives for K3B are on both the CD and DVD versions of Knoppix.

Swiss Army Knife looses its blades/tools.

No longer can the CD version of Knoppix be thought of as a Swiss Army Knife or technicians toolkit, it’s been reduced to a single blade :-( It has evolved to become a base platform for hobbyists to extend. It’s a shame, I have utilized Knoppix for many years as a diagnostic tool kit. Its usefulness as such is now diminished and I have been using Ubuntu as a supplement since Ubuntu is on a regular release schedule. Now Knoppix is actually outpacing Ubuntu in releases and includes later versions of the Linux kernel and web browsers. I look forward to where Klaus Knopper takes this platform during 2010 and beyond.

Gains ability to install bootable image on flash drives and SD cards.

Knoppix since the 6.0.1 release has had a really nifty feature whereby a fully working and bootable copy of Knoppix can be installed onto a USB Flash Drive or SD Card using a  built-in utility. It just takes a few clicks to install, previously this feat was only for the most technical, now your grandmother could do it. The utility is very safe, not allowing you to install on a mounted device by accident (ie the HD you just booted from). This feature makes Knoppix truly portable and capable of saving configuration changes and locally stored files between sessions. I have found the ability to boot systems to Knoppix on an SD card to be especially useful, netbooks and other modern systems support booting from a memory card. SD cards are so much more compact versus a CD or USB flash drive. Carrying a bootable operating system in your camera bag is very feasible!!

Kick its Tires!!

Interested in kicking Knoppix’s tires? Visit their website and download from one of many mirrors.