On ott 16 12:25, Martin Husemann wrote: > I have a few clarifications...
Thanks for writing them. > > Maybe this is trivial, but during the installation of NetBSD a > > disklabel is actually nested inside a primary MBR partition. > > This is true for some architectures (like amd64), but others do use plain > disklabel on a disk without any MBR. This also works on amd64 when you > do not need to boot from the disk. Yes, exactly. I tried to specify this (``Note that the above behaviour is about amd64; for other ports it may change''), maybe I could have better positioned the sentence. > > - to grant the compatibility with PC/DOS (and other OSs like Windows > > this way can still use the same disk); > > - to grant a regular boot on PC/IBM hardware (where, without a valid > > MBR, the BIOS could not even try to search a bootloader on the disk). > > Yes and no - newer sysinst versions allow to kill the whole disk content > (including the MBR and whatver partitions exists), and start from scratch > (as if the disk had been totaly wiped before). Use with care - this kills > all data on the disk. Oh, ok, maybe I did not dig enough in newer installers. > The (single) disklabel can then describe partitions outside of the NetBSD > partition too (as seen when setting up (U)EFI booting on disks with MBR > partitioning - the EFI boot partition shows up in the disklabel). Thanks for pointing out this. > That is kind of correct once the kernel is running. Yes, I was meaning this. > This is not true - you can select GPT for boot disks with both firmwares. Ops, again my fault about newer installers. > You did not stress the (from my POV) most important points of all this mess: > > - if you need the disk to be accessible from other systems, you need to > use a partitioning scheme they understand. MBR works for DOS and older > windows, GPT works for nearly everything newer. Disklabel only works > for older Unix systems or NetBSD. I did not specify this about GPT, but as regards MBR DOS compatibility... the whole message is about this topic. Maybe a recap was missing. > - if your disk is larger than 2TB you can not use MBR (you may have luck > with some systems upto 4TB, but the "portability" is lost), nor can > you use disklabel. Select GPT (sysinst knows about the size limits > and will avoid non-working selections). > > The topic is confusing, thanks for summarizing! Thanks to you for all the clarifications and integrations. Rocky
