http://norman.walsh.name/2005/03/09/upgrade 8 39 2005-03-09T17:26:06-05:00 $Date: 2006-08-22 11:26:24 -0400 (Tue, 22 Aug 2006) $ Norman Walsh 2005 Norman Walsh A short story about upgrading the boot disk. Linux. Because rebooting is for hardware upgrades. As I said, the main server in our house (“hera”, in case you're curious) was going down. The problem was an aging disk. Not yet dead, but making more noise than some jet engines. Actually, I have a small stack of drives in that state now; I must be the victim of a Poisson distribution over the MTBF. Or something. Anyway, it was going to have to be replaced, but I wasn't sure when until I saw 80Gb drives on sale for well under a buck a gigabyte. I guess that's not news, but it still looks pretty remarkable to me. The next problem was, how do I get all the data off the old disk and onto the new disk? I could open up the machine, install the new drive as a second drive, do the copy, then open the machine up again and swap. Except, (1) it's tedious to get the machine out of the closet, (2) I want to minimize downtime, and (3) there aren't any spare drive bays in it. Well, one of the other dying drives is my external Firewire drive. Its main problem is disk errors and one of them occurs at an inopportune moment in the boot cycle: it hangs the IEEE1394 driver in the laptop when I attempt to access it. Ok, here's a plan: let's rip open the external enclosure, put the new drive in there, hang it off the laptop, rsync the data, then swap the new drive into hera. Works for you? Works for me. Pop off the plastic clips that hold the drive case together. Open up the drive. And discover that it's held together with tape. Rip all the tape off and discover…it's held together with four perfectly good mounting screws. What the heck was all that tape for? Pull the drive off. Swap in the new one and perform the steps in reverse. Except for the tape, of course. Next step, partition the new disk. I wanted to make the partitions on the new disk the same as the partitions on the old disk so that all the mounts and stuff in the init process would work without any fiddling. To do that, I compared the old partition table to the new one…and discovered that the new disk is eight times larger than the old one. And twice as large as the second drive in there. The new disk is going to replace both of them, with room to spare. The rsyncs run overnight. Time to swap drives. Pull the drive out of the external enclosure, pull hera out of the closet, open it up, swap. Done. Almost. See, while I got the partitions right and made the right partition bootable, I didn't actually install any sort of boot record. Did I remember to make a boot floppy first, like I reminded myself to do before I ripped the old disk out? Of course not. Time to wack the old disk back in for a minute to make a boot disk. There. Close it up, put it back in the closet, reboot, and…it all just works. Sweet. Even better, my big external drive with the disk errors doesn't cause any problems as the second IDE drive in hera. It still has disk errors, of course, but now I'll be able to copy the data off it before it becomes a paperweight. Now what do I do with three hard drives that all sound like jet engines taking off? A grand total of 70Gb, worth about fifty bucks if they were brand new. I'll think of something, I suppose. Temporary storage for the data on the disk with errors, for a start. By the way, check out the “light tubes” used to direct the light from the LEDs in the back of the enclosure to where the end user can actually see them on the front. Cool.