On Fri, Mar 18, 2016 at 2:45 PM, Allan Jude <allanj...@freebsd.org> wrote:
> On 2016-03-18 17:41, Freddie Cash wrote: > >> >> On Fri, Mar 18, 2016 at 10:39 AM, Conrad Meyer <c...@freebsd.org >> <mailto:c...@freebsd.org>> wrote: >> >> On Fri, Mar 18, 2016 at 10:03 AM, Allan Jude <allanj...@freebsd.org >> <mailto:allanj...@freebsd.org>> wrote: >> > On 2016-03-18 12:33, Guido Falsi wrote: >> >> >> >> Hi, >> >> >> >> I have just update one of my machines and noticed the booloaders >> files >> >> got quite fat in the last few days, some by a big margin. >> >> >> >> on an updated machine(r296993): >> >> >> >> -r--r--r-- 1 root wheel 85794 Mar 18 16:47 /boot/gptboot >> >> >> >> from a machine I still have not updated(r296719): >> >> >> >> -r--r--r-- 1 root wheel 16059 Mar 13 21:01 /boot/gptboot >> >> So the loader grew 70 kB. How big are your disks? >> >> >> I noticed because mu gpt boot partition is 64K and gptzfsboot just >> >> passed 100K. >> > >> > This is a side effect of the loader gaining the ability to boot >> from GELI >> > encrypted partitions. >> > >> > ... >> > >> > Maybe we should be putting the GELI enabled boot blocks in a >> different >> > filename? I generally wanted to avoid creating a new version of >> each >> > bootcode with GELI support. >> >> >> I think we should just suggest that boot partitions be much larger >> than 64kB (1MB is still <0.1% of any disk sold today) and not worry >> about it too much. Embedded applications can disable GELI loader >> support to save a few bytes. >> >> >> The boot partition doesn't necessarily need >> to be 1 MB (and can't due to some issues with the assembler used right >> now, or something like that). We just need to make sure people have >> slack space in their partition table to expand into in the future. >> >> Using "-a 1M" in your gpart command to create your first data partition >> gives you that slack space. >> >> gpart create -s gpt ada0 >> gpart add -t freebsd-boot -s 256K -l boot ada0 >> gpart add -t freebsd-ufs -s 10G -l root -a 1M ada0 >> >> That leaves ~756 KB of free space between the end of the boot partition >> and the start of the first data partition. Increasing the size of the >> boot partition in the future is as easy as (no formatting of disks >> required): >> >> gpart delete -i 1 ada0 >> gpart add -t freebsd-boot -s 512K -l boot ada0 >> gpart bootcode -b ... -p ... ada0 >> >> It's a handy pattern I've gotten used to over the years, ever since the >> first 4K sector harddrives were advertised (as alignment of filesystems >> was/is *very* important). >> >> Even on disks that will be used solely for ZFS I've taken to creating >> GPT partitions starting at 1 MB. And it's saved me from having to >> reformat disks when moving from a separate root filesystem (no USB >> sticks) to root-on-ZFS as there was 1 MB of free space at the start of >> every disk for creating boot partitions. :) >> >> -- >> Freddie Cash >> fjwc...@gmail.com <mailto:fjwc...@gmail.com> >> > > This also has the handy side effect of allowing you to switch to booting > with UEFI, which currently uses an 800kb fat file system And I'm pretty sure I read somewhere that the 10.x installer defaults to using "-a 1M" when partitioning new disks, although I haven't installed any 10.x systems from scratch yet (just upgrades from 9.x). -- Freddie Cash fjwc...@gmail.com _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
