On Wed, May 09, 2018 at 09:06:24AM +0000, Rudolf Sykora wrote: > Hello misc, > > I wanted to use a MBR partition for backup purposes, > so I (almost) created (using fdisk) another OpenBSD MBR (A6) > partiotion, but then I got the message > > MBR contains more than one OpenBSD partition! > Write MBR anyway? [n] > > So am I doing it wrong?
Well. Yes. The BSD's has got a disk label of their own, and OpenBSD has got it's disklabel inside the MBR:s OpenBSD partition, when MBR is used. So there is supposed to be only one OpenBSD partition containing the BSD disklabel describing the OpenBSD view of the disk's partitioning. If you have more than one it might work, if all parts of the system selects to use the same OpenBSD MBR partition, and only warns about the second. But only that one MBR partition, with its BSD disklabel, will be used. I have heard of variants where you set one MBR partition at the time to A6 and the other to something else, which it messy. And it is not intended to operate that way. You could use one OpenBSD MBR partition and in the BSD disklabel allocate a big partition of type RAID. Then use that partition in softraid as RAID 0 or CONCAT - they might allow using a single chunk. Or as CRYPTO with a dummy encryption key. On the new softraid disk you create an MBR OpenBSD partition and so on... See softraid(4), bioctl(8) and https://www.openbsd.org/faq/faq14.html#softraid Whether that is a good suggestions depends very much on what kind of backup you have in mind. There are probably many other more BSD:ish ways to do it than you think. So please describe more in detail what kind of backuping you want. > > Thanks for comments! > > Ruda -- / Raimo Niskanen, Erlang/OTP, Ericsson AB
