PC1: Hello, I’m a PC
PC2: And I’m also a PC.
PC1: Ooooh, my aching disk controller.
PC2: What’s the matter, PC1?
PC1: Well, I’ve got these two 250GB drives and they work fine in isolation, but whenever they are in a mirrored configuration, they develop subtle filesystem corruption problems. That leads to kernel panics and spontaneous reboots. It’s not nice. I’ve tried both the hardware and software RAID1 solutions, and it’s the same deal both times.
PC1: Yes. So far I’ve been limping along in software RAID mode with write caching turned off. This mostly prevents the filesystem corruption but not entirely. Also it makes writes glacially slow.
PC2: How slow?
PC1: Like, about 6 MB/sec. About 6 times slower than they should be. Let’s see, at that rate, it would take about 11 hours to fill the disk. I could get a new SATA controller card, but what’s the chances the same thing might not happen again?
PC2: Well listen PC1, why don’t I take over the file server duties with those disks? I’ve got two SATA ports on-board, everything should Just Work. Pretty sure I can handle the extra load, I have an Athlon XP 3200+ CPU, you know.
PC1: Hey you don’t need a fast CPU to be a big dumb file server, bub. My Celeron 1.13GHz suits me just fine. But anyway, sure, knock yourself out. Just get yourself set up with the latest FreeBSD 6.1-RELEASE and then we’ll get those drives installed.
PC2: Well that didn’t go so well.
PC1: Why, what happened?
PC2: Well I got FreeBSD installed OK, but then I found out the bad news. There is no nVidia driver for FreeBSD/amd64. And the standard X.org driver refuses to work with my new Dell LCD monitor.
PC1: Oh, poor diddums. I don’t even have a monitor and you don’t see me complaining.
PC2: Well your lack of monitor might have something to do your integrated graphics chipset, but the less said about that, the better. So anyway, back to me. I was a bit stuck without the graphics driver, and it was the perfect excuse to do something I’ve always wanted to do.
PC1: What, get that Hello Kitty desktop theme installed?
PC2: No, something more drastic than that. I’ve switched to … Ubuntu Linux!
PC1: OMG, you must have been desperate.
PC2: Don’t be nasty. Anyway, it worked. Ubuntu seems to recognise all of my hardware. Well, almost all. Unfortunately, I had the same video sync problem that I had encountered with FreeBSD. Fortunately, there was a “safe VGA mode” on the installer live CD. Unfortunately, it didn’t work. Fortunately, there was a workaround. This was enough to get Ubuntu installed, and then the official nVidia amd64 video driver.
PC1: So after all that, are you ready to install the drives? They’ll need to be re-fomatted because Linux doesn’t understand UFS very well. Tell you what, I’ll give you one drive, you create a RAID-1 array with one disk and one one missing disk. Then copy all the stuff across, I’ll give you the other disk, and you can rebuild the array.
PC2: Sounds like a plan.
(more time passes)
PC2: Ubuntu doesn’t like me.
PC2: Shut up, nerd. Apparently
mdadm is the RAID tool of choice for Linux, so I installed it. But it requires RAID “personalities” to be loaded into the kernel, and I have no idea how to do that. Also it requires
/dev/md0 to be present and, well, it isn’t. All of the RAID doco starts with those two basic requirements and I have no idea why my system is not meeting them. I can create
/dev/md0 using the
sudo mknod /dev/md0 b 9 1 magical incantation, but it goes away next reboot. No idea what’s going on.
PC1: So I guess I’m still useful for something after all! I may corrupt my filesystem once in a while but at least I have one!
PC2: Ubuntu doesn’t like me, I told ya.
PC1: Don’t anthropomorphise operating systems. They hate that.