Entries tagged computers:gold

As I wrote yesterday I've recently ordered, and now received a new desktop machine. For completeness I've now finished juggling machines around and installed etch twice - so now I have two working desktop machines:

gold.my.flat (unstable)

This is my personal machine, fitted with 4Gb of RAM.

It is currently running 6 xen instances of 256Mb each leaving me with more meory free than I have ever had upon my desktop machine - so the upgrade was definitely worthwhile!.

(The previous machine had bad sockets and couldn't take more than 1Gb of RAM - hence the replacement rather than mere upgrade.)

vain.my.flat (etch)

This, reinstalled, machine is now running only backuppc and those programs that Meg/random guests wish to run.

In terms of networking I've now split things up into three well-defined ranges. Knowing how things develop I'll not expect this to contining, but right now I'm pleased with:

• 192.168.1.0/24
  • These two desktops, a printer, and any wired laptops that are turned on.
• 10.0.0.0/24
  • Xen guests
• 10.0.1.0/24
  • Wireless DHCP range.

All in all I'm very happy with the work of the day even if I did have to rsync stuff all over the place, juggle power cables and install Etch upon both the new machine, and the re-purposed backup machine. (Since that was previously my mahcine and was running sid.)

The following links were helpful.

• Setting up a server for PXE network booting - Used to do the reinstalls, since I don't have optical media handy.
• A simple introduction to working with LVM
• How to set up an encrypted filesystem in several easy steps

All being well tomorrow will be spent tidying the flat, drinking with my erstwhile cat-sitter, and getting ready for work on Monday.

Tags: computers:gold | 6 comments

Today I rebooted my desktop for the first time in a few months. This did not go well. Probably as a result of this issue with lvm/dmsetup/cryptsetup conflicting my system didn't boot, and the error message was non-helpful.

The error shown just after grub2 had started to load a system was :

Cannot find LVM volume group gold-vol

The actual cause was that I was missing the mdadm package. D'oh. My desktop has 2x500Gb drives setup as:

 sda1 + sdb1 = md1  = /boot [1Gb]
 sda2 + sdb2 = md0  = LVM storage [460Gb]

(It's only as I write this that I'm surprised that md1 + md0 are opposite to the fashion I'd have expected them to be. I guess I just created them in the "wrong" order at install time. Oops)

So without mdadm the LVM volume group on /dev/md0 couldn't be found, and that in turn meant my root filesystem couldn't be accessed at /dev/gold-vol/root.

Fixing this was a real pain. Because the system is the PXE network host on my LAN I couldn't boot it that way, and the machine has no CD-ROM drive connected.

My solution was to download and install System Rescue CD, which I placed upon a USB stick. This worked beautifully once I realised I had to boot with rescue64 to get a 64-bit kernel capable of letting me run chroot.

Oddly enough I had problems booting from USB. If I powered down my system and hit the "on" switch the system just ignored the USB stick. I noticed that my USB mouse and card reader didn't show any power lights at all - not until after grub had failed to boot the system.

So the process of booting from USB was eventually determined to be:

• Poweroff system.
• Power on system - wait for grub to fail to boot kernel.
• At this point the USB mouse and card reader would be initialised in some fashion and would show their LED lights.
• Press Ctrl-alt-delete - at which point the BIOS would allow the USB booting to occur.

Very very odd. I guess its a question of what does the "USB enabling". I'd previously assumed the BIOS would do this setup - but looking over at another system I notice that the USB mouse doesn't "come alive" until mid-way through the Linux boot process even though I know that BIOS has options for "Enabling USB mouse & keyboard". Maybe I'm missing something obvious ..?

In conclusion .. I restarted GDM for the first time in weeks and rebooted, and this was a bad idea.

ObFilm: Never Been Kissed

Tags: computers:gold, mdadm, recovery, usb, usb booting | 3 comments