[OmniOS-discuss] SSD alignment, EFI label rpool support

[Paul B. Henson]

While putting together a linux system, I found the current advice in 
that ecosystem seems to be to align your SSD partitions not just to the 
page size, but to the erase block size. Any thoughts on that 
recommendation for an rpool, l2arc, or zil partition?

I'm using a couple Crucial 256G m4 SSD's for my rpool, which I believe 
have an 8k page size and 512k erase block size. Given the rpool 
requirement for an SMI label, I would end up having to start the slice 
on cylinder 15 (which, when added to the one cylinder used by the fdisk 
label, results in cylinder 16) in order to get the alignment right, 
which wastes something like 150Mb :(. Not ridiculous on a 256G device, 
but annoying. Has any progress been made on booting from EFI labeled 
disks? I vaguely recall somebody was working on grub2 but I'm not sure 
where it ended up. That would allow alignment without as much waste.

Or if erase block alignment doesn't matter that much for ZFS I could 
just align to the page size…

Thanks…