Jan Stary wrote: > This is 4.5 trying to create a FAT partition > on an external (USB) 80G disk.
condensing... (Those who scream about the horror of top posting obviously don't have a netbook. Having to flip down twenty screens worth just to see something one hasn't seen five times already is annoying and a good way to get ignored by me.) ... > # fdisk -i sd0 ...openbsd partition created... > *3: A6 0 1 1 - 9728 254 63 [ 63: 156296322 ] OpenBSD > > > # disklabel -E sd0 > # Inside MBR partition 3: type A6 start 63 size 156296322 > Treating sectors 63-156296385 as the OpenBSD portion of the disk. > You can use the 'b' command to change this. > > Initial label editor (enter '?' for help at any prompt) >> z >> a > partition: [a] > offset: [63] > size: [156296322] 30g > Rounding to cylinder: 62926542 > FS type: [4.2BSD] msdos whoa. You just made your OpenBSD partition into an OpenBSD partition with an msdos identifier string. You don't want to do that. >From this point onwards, things are broke. It just takes you a while to realize it. :) ... > The 'a' partiton is there, but once I try to create a filesystem on it, > it disappears from the disklabel. Am I missing something? yes. :) Don't think of "I must do this, then that, then bla and then all is well". Think about the data...what is where and what it all means. On i386 and similar systems, the fdisk partition table determines what OS goes where. It is in the first sector on the disk, all co-existing i386 OSs know that and expect it there, as does the boot ROM in the machine. Problem number 1 is you carved out an OpenBSD partition and tried to call it MSDOS within OpenBSD. Problem #2 is you created a disklabel on a drive that you had no intention on using for OpenBSD. Disklabels are an OpenBSD way to slice up the OpenBSD partition of the disk. Only OpenBSD uses OpenBSD disklabels. Ask yourself this question: where do you does the OpenBSD disklabel go on the disk? In the OpenBSD partition, of course, no where else is "safe" for it to be. OpenBSD knows to work around and use the disklabel. Now, you make an MSDOS FAT file system on the OpenBSD partition. What happens to the disklabel? Yes, you just clobbered it. MSDOS never had reason to think about working around an OpenBSD disklabel. It doesn't. By this point in time, even if MS decided it wanted to offer full support for OpenBSD, it can't. When you PROPERLY create an MSDOS partition on your disk (and not an OpenBSD partition), OpenBSD will see it and create a "pretend" disklabel for you that will be and do everything you need a disklabel to do. Do not try to change it, you won't do better than what is there, and more importantly, where do you think the disklabel would end up? See most of FAQ14 for a lot more details on this. You need to create an MSDOS partition, let the system create its own disklabel for you, and then newfs that. Or better: just use a native MSDOS or Windows machine create the partition for you. OpenBSD has the ability to create valid drive layouts that Windows is confused by (it can also create some really wacked invalid layouts, too), and philosophically, I tend to prefer to use native tools when possible. > Also, why does disklabel say '16 partitions'? That is how many disklabel partitions OpenBSD supports on all platforms. You may think this uninteresting, but that means you haven't played with SPARC systems which usually only support eight partitions...but with OpenBSD, magic happens and you end up with 16 partitions in such a way that the SPARC boot ROMs (and even Solaris to some degree) still work (for the first eight). Even if you don't use them, all 16 partition table entries exist and could be used later, if needed. Nick.
