I thought i'd share a little tale that hilights the importance of backups (including spare hardware that's verified to work).

Like many geeks I have a cupboard full of old computers and computer parts, including one whole system that has all the same specs as my main desktop and lacks only the harddrives (for use as an emergency backup if my main system fails). I also have various online services and external USB drives for taking backups.

Problem is I don't take those backups often enough.

When my main desktop died recently (i've been having overheating issues for a long time - they finally killed my CPU) I tried to fix it, found it just wasn't booting no matter what I did and pulled the drives to use with the spare hardware - the spare hardware that hadn't been tested for months and was in the cupboard.

This spare machine did boot to the BIOS and the bootloader started fine. However as soon as the kernel loaded and went into protected mode (first thing it does after loading) the computer shutdown. I tested with a few different kernels and other operating systems and only FreeDOS would boot.

On advice of a friend I updated the BIOS from FreeDOS. I got a few shiny options in the BIOS setup utility, but it still didn't boot into protected mode no matter what I did.



Fearing the worst (since this was identical hardware apparently to the old system and so the software configuration on my old harddrives should "just work") I ordered some external drive enclosures on the theory that i'd have access to my data from my laptop (not having another desktop machine to use this was the only option). I also ordered a new motherboard, CPU and RAM thinking that in a worst-case scenario i'd reinstall the OS.

When all this stuff came, I stuck the new mobo,CPU and RAM into my original desktop and crossed my fingers. It booted fine, but there was filesystem damage from not shutting down properly.

LUCKILY I had lost no data and the drive enclosure remains in the original packaging. However the whole incident has made me learn a few lessons:


1 - If you have some spare hardware for emergency use, boot it every now and then to test it

2 - Make regular backups - don't procrastinate. I was lucky not to have lost my data, but next time I might not be. I'm now setting up a cron job to automatically backup my home directory and anything else of importance

3 - Check those backups and make sure it's easy to restore the whole lot or just a single file. I had my TMA02 open when my desktop first died and was very concerned the filesystem damage may have caused it to not be saved correctly (luckily I had in fact saved it just a minute before the shutdown so didn't lose a lot of work). If the file was corrupted I may have had to restore that single file from backup.

4 - If you're storing backups anywhere but your own property, encrypt it. Even if you think nobody's interested, if you do a full system backup and you use your computer on a regular basis there WILL be some sensitive information in there somewhere. Better to be safe than sorry. Encrypting your backups also allows you to safely pass them to random strangers for safekeeping (so long as you use strong enough crypto - be paranoid). I've long been encrypting backups of a website's database I run and then letting random users keep hold of the encrypted backup.

There you go, that's today's safety lesson.

[gareth@lovely ~]$ uname -a
Linux lovely.home.garethnelson.com 2.6.27.19-170.2.35.fc10.i686 #1 SMP Mon Feb 23 13:21:22 EST 2009 i686 athlon i386 GNU/Linux

With regards to RAID, what specifically would make the hardware raid built into my motherboard "not much good"? It would seem to have superior performance due to offloading the processing required to the hardware, or am I mistaken? Software RAID or something similar (there's RAID-like features in the linux LVM which is used by default in my distro of choice) would appear to require more processing done by the software RAID driver whenever there is disk I/O.

I'm not using a PAE kernel either and it definitely is not an intel chipset. I was using a PAE kernel at one point but found that the nvidia drivers did not like it and thus I had no 3D acceleration.

As you can see, it's kinda ancient (fedora core 10, latest is fedora core 14) and in need of an update anyway. If i'm going to update it I might as well go 64-bit.

This chipset supports up to 16GB of RAM, so that isn't a problem.
I've never heard of mixing 32-bit userspace (and kernel modules? or just the userland modprobe?) with a 64-bit kernel, though I can see why it would work.