Fighting with computers

Computers are not always friendly.

Wednesday, December 29, 2004

Of foldable bikes

I live in a flat in a six storey building close to the campuses of two universities. As parking and traffic really suck around here I decided to get a bike.

But lacking of parking place the obvious choice was to get the bike back home with me. You just cannot park it in the streets if you want to keep it for a long time. The problem was, then, to get the bike from the street to my flat.

I've seen some people tilting bikes front-wheel upwards so they can fit it in the elevator but it didn't seem to me very convenient, and then you'll need some real estate inside your home anyway.

I've learned about several brands making foldable bikes (Dahon, R-M, Brompton). Minutes later I've learned too that this stuff was expensive. I finally settled with a Dahon's Vitesse 3D for 425 Euros. It was a trade-off (and one of the less expensive alternatives) between folded volume, price and comfortable ride. I'm quite happy about the bike although I still think it could be cheaper (you can get a better price in USA).

Now I'm getting a second bike for my kid to go to school, but a 16" Dahon's Piccolo seems to be not as foldable as my 20" Vitesse. It can be folded quite compact but using tools and not the 15 seconds it takes to fold the Vitesse.

By the way, forget my complain about G4U software. It had worked Ok, but somehow our system's operation fill all the data partition until the system crashed.

Sunday, December 26, 2004

New article

January 2005 issue of Circuit Cellar Ink magazine contains my article titled "Build a Digital Video Recorder" with some clues about doing exactly this.

Some days ago I was told some the systems that were cloned using G4U software seemed to have a lousy filesystem now. As the problem seems to be repeatable, it looks that the cloning process was not flawless for reasons yet to be determined (I'm in the process of finding out).

Tuesday, December 21, 2004

It didn't take long before I have to use it

My kid's computer harddisk was dying last week. It booted up and it worked but sometimes after a clean shutdown CHKDSK was triggered on next boot (they use XP pro). The check was reporting some damaged sectors and I knew a replacement was due. I better do it now or I will have to reinstall everything from scratch.

I went to the shop and I've got a new 160GB Maxtor drive. But, as usual, things were not exactly smooth: Old drive was a 40GB IBM drive with a single FAT32 partition. I wanted to get a bigger partition as the new drive was larger and I wanted to copy the old winxp system onto the new drive.

Unfortunaltely, due to some defective clusters, G4U software stopped after copying only 6 GB and the result disk was unusable. G4L also failed because of the same reason. I borrow a copy of Ghost 2003 for DOS just to discover that I needed a boot floppy to run it and that my floppy drive was not working and full of dust. I got rid of the dust from the floppy and it eventually worked and so did Ghost 2003 that also allowed me to expand the destination partition.

Other solution that did work was the rescue mode of G4L that is also able to copy a partition with (some) defective clusters. What it did not work for me was "parted" software afterwards to expand the 40 GB partition onto a bigger one.

In the mean time I decided to install Ubuntu Linux on the same system, but unfortunately I was not aware that my motherboard BIOS was only capable to handle 137GB of my harddrive, and I managed to install Ubuntu in the last 4GB of my 160GB drive, so I could not boot it. Even worse, I accepted the recomended setting of using GRUB boot manager on my disk MBR, so afterwards I just got an Error 17 instead of a boot menu, so I could not boot either WinXP or Ubuntu Linux.

This latter incident was fixed by FIXMBR command from winxp install CD-ROM rescue mode and later on Ubuntu was moved to a new home within the harddisk below the 137GB limit.

Now everything works again but most of my weekend had gone trying the different approaches until succeeding. I did not mention all the attempts just to keep things short (I even was told to say a little prayer).

Friday, December 17, 2004

Some interesting tools

My last project dealt wih the use of 1U rack-mounted PCs. Once the software was ready for deployment I needed to find an easy way to get the operating system and applications loaded onto the systems and I was looking for an easy and fast way of doing it.

The units I am using are manufactured by Supermicro and they have no floppy or CD-ROM but are equipped with dual Gigabit Ethernet ports and USB 2.0. While booting the system up from a USB CD-ROM was possible this was leaving me with the task of manually configuring each unit.

I've used in the past Symantec's Ghost software for harddisk clonning and I've found it quite useful. But to be able to use it in this case I would need to boot these computers out of a floppy disk or specially crafted CD-ROM that I don't have ready. On the other hand, a Ghost license will need to be purchased.

Browsing around I've found a couple of projects G4U (Ghost for Unix) and G4L (Ghost for Linux) that offer you a ready to burn ISO image. You boot up your system and you have network support (Ethernet) and some basic tools to recover (or to send) a harddisk image from (to) a server so you can clone disks quite easily through the network.

As in my project I needed to boot the system and get the OS and apps installed, I can boot up off the CD-ROM and get the disk contents from my FTP server. The whole operation takes around 4 minutes over Fast Ethernet (used disk size has a big impact on this time, as you can guess).

If you have some time to spare you can follow the thread on both tools websites where G4U 's author complains of G4L 's plagiarism.

If your code does not change very often and you disk image is not very big you might want to copy all together in a single CD-ROM or DVD-ROM so you don't need to use the network nor an FTP server. Although in this case you will notice that both drives provide lower throughput than a network link and therefore the clonning process can take longer.

I've recently got a 60GB USB 2.0 bus-powered TEAC harddisk and an LG 1GB USB 2.0 pen drive, I've been looking around for alternative ways of booting up computers. Booting off a USB seems quite interesting to me. I've found that St. Petersburg Linux does exactly this. But if you have more space on your USB drive you can even boot up Knoppix.