Moving from GRUB to BSD Loader



Suppose, for the sake of argument, that the host in question has a RAID-Z or RAID-Z2 drive configuration. Would you have to restamp each individual drive? What about with encrypted disks (though last i knew, TrueOS had issues with those)?

I’m just asking because I am trying to document use cases to my wiki.


I’m guessing yes you probably should. If you internet searched for “zfs raidz boot drive freebsd install” you’d probably find enough to give you a definite answer. Or grab Michael Lucas ZFS and Storage Essentials books (lots of really good stuff in them). One of the devs that work on the FreeNas stuff at ixSystems can provide a definitive answer.

This is a little bit of an older link and talks about how to do an install, but is still relevant

My opinions below, based on me mucking around at home, not doing anything for big data storage/performance.

Everyone and their use cases are different, but for me with home use, I like using mirrors. Separate stuff for the OS and user home/data directories, a pair of Samsung EVO 850 SSDs don’t cost much, so go put them in a mirror for OS/booting, then WD Blue drives in mirror or RAID to suit your storage needs. Heck the way ZFS works you could go and create RAID-Z out of mirrored pairs just because you can.

Oh, ZFS is great at using a whole disk, but when you start mirroring/RAIDing you need to remember that one makers “TB” is not the same as anothers (powers of 2, powers of 10), so even if you use the whole disk, you may want to actually use gpart and put partitions on them, so that you control where they start (-a 1m) and the size of the partitions match across devices. ZFS nicely uses partions instead of whole devices as you’re building up things.


Hi RodMyers:
If a user has an MBR on their drive, the above directions will NOT work.



This can be as simple as gpart show and taking a screenshot / saving the partition maps associated with a particular device.

The best solution for MBR users is to write down their partition (slice!) offsets and re-create the slices using GPT. Until this is accomplished, the above steps will not help.

Also, note that the freebsd-boot partition MUST be reasonably small (less than 512k in size, but larger than the size of the /boot/gptzfsboot file).

I just suffered through this process of going from GRUB to the BSD Loader on an MBR disk, and can say with certainty that the easiest solution is to immediately migrate to GPT, rather than dinking around with e.g. zfsboot or trying to keep GRUB happy.


Are the instructions in post #1 no longer current?

I do not see gptzfsboot in /boot.

Will it cause problems to just keep using grub? I have a GPT/BIOS system which can’t do UEFI.


I will ping @kris and see if they need to be updated



AFAIK that file hasn’t go well away. I’ll check it in the next few days though


Kris should be looking at this issue this week