On Sat, Sep 20, 2025 at 01:09:16PM -0400, Steve Litt wrote: > MBR is both a boot scheme and a partitioning scheme. As a partitioning > scheme, it's limited to disks 2TB or smaller.
True > If used on a bigger disk, > only 2TB is available, which of course is a waste. This is misleading. OpenBSD doesn't care much about the MBR partitions, especially on a non-boot disk. A large disk that is configured with a single 2 Tb MBR partition of type A6, (OpenBSD), can have much larger disklabel partitions created and used on it. > GPT is a partitioning scheme which can handle a disk a billion TB, so > it will be many years before we outgrow it. It's what you use on disks > more than 2TB. Use of GPT on disks > 2 Tb is not obligatory, (nor necessarily desirable), on OpenBSD systems. In fact, on non-boot disks it's possible to not bother with either MBR partitioning _or_ GPT, and just write a disklabel to the raw disk. As far as OpenBSD is concerned, it will work just fine, because the BSD disklabel is all that is required to define the partitions that OpenBSD uses. (But there _are_ things that can go wrong with a 'disklabel on the raw disk' setup, so one again this falls in to the category of don't do it unless there is a very good reason not to use an MBR with a single A6 partition covering the whole disk, and you know all of the pitfalls.) > To get the best of both world, you can have a <2TB NVMe or SSD as the > boot drive, and a big honking 20TB spinning rust drive for data True, a 512 Mb SSD is fine in virtually all cases as a system boot drive. Keeping user data on a second disk makes it much easier when it comes to upgrades and especially re-installs. You don't even need to put the actual /home directory on the second disk, just make a small /home on the boot disk for things like user configuration files and work in progress, and create a second alternate 'home' directory on the second disk with more space for bulk storage.
