10 January 2010

Why you should never own a computer, part 598

  1. NSTAR has some sort of power outage. My lights go off for a few minutes. L. asks if my computer will be OK. Of course, I say, it will reboot automatically. Sure enough, when the lights come back on, its power light comes back on.
  2. Later that evening, I try to log in to check my mail. But I'm getting "no route to host." Odd, did it forget its static IP? I turn on the monitor. "Check signal cable." I press a few buttons on the keyboard. Nothing. Reboot. Nothing. The num-lock light doesn't toggle when I press "num lock", which suggests that the motherboard is blown. But I'm using a funky USB keyboard. I try a PS/2 keyboard. Nothing. I try plugging the monitor into my laptop to see if it's a signal cable problem. Nothing. The mobo is probably blown.
  3. Fortunately, I have a second computer with better specs gathering dust. I pull the hard disks from PC #1 and put them in PC #2. PC #1 was ATA-only, PC #2 had SATA and ATA. I plug the two ATA disks into the ATA port. I no longer remember which one had the boot volume. I guess the smaller one and make it the master and make the larger one the slave. I boot.
  4. The boot sequence stops just before GRUB would normally load. Oops. Are the hard disks fried, too?
  5. I plug in the SATA drive and boot from that, successfully. I mount the two hard disks without incident. I apparently had the boot volume wrong: it was on the larger disk. Ah, no wonder. Maybe it only tries to boot from the master. I shut down, unplug the SATA, and plug in just the larger drive as the master. No slave. GRUB loads. Good.
  6. I swap the drives' positions (cable geometry prevents me from simply exchanging the connectors) and make the larger drive the master and the smaller drive the slave. But when I boot, the boot sequence still sticks before GRUB.
  7. Disconnect the slave. Boot works.
  8. Bizarre. I have no idea why this is happening. Fortunately, I have an ATA card in the old machine. I plug that in, and connect the slave to it. GRUB loads.
  9. Now, the boot sequence halts on "unknown USB device." That's odd. I disconnect the keyboard and reboot. As I suspected, that was just the last error message. The actual error message that signalled the halt was that the system was waiting for the root device. For reasons I do not fully understand, the root device was hda1 on the old machine and is sda1 on this machine. The next time Grub loaded, I hit 'e' to edit the command line and changed root=/dev/hda1 to root=/dev/sda1.
  10. Now the system booted, but halted with a complaint about being unable to run fsck. Probably had something to do with all of the /etc/fstab entries being wrong. It asked me to enter the root password, which I thought I knew but apparently did not. I hit Control-D to skip it, wondering if it would mount / read-only and make it impossible for me to change the password without booting from CD. (I went looking for one, without success.) Fortunately, it mounted root read-write, so I changed the password, changed all entries in /etc/fstab from sda to hda (and from sdc to hde, for the second drive. dmesg had indicated that it was hde.) I also did the same with /boot/grub/menu.lst.
  11. When I ran grub-install, grub complained that it didn't recognize /dev/hda. I had forgotten to update /boot/grub/device.map, which I then changed from sda to hda. Now, grub-install actually worked.
  12. Reboot again. Now, I still can't ssh into the machine. What the heck? I checked dmesg and saw "udev: renamed network interface eth0 to eth2". I have no idea why udev was randomly renaming network devices, but I went along with it. I edited /etc/network/interfaces and changed eth0 to eth2. After running /etc/init.d/networking restart a few times, the interface actually came up.
The short moral of the story is to buy a UPS, or, failing that, have replacements for everything. The real moral of the story is to get someone else to handle your hardware.

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