ZFS and GPT boot - size issue bootblock v.s. default of sysinstall

[Allan Jude]

On 2016-12-28 14:41, Dirk-Willem van Gulik wrote:
> On a default ZFS install (late 2014, 10.x) of a few years hence it seems sysinstall selected 64k as the default size of partition 1: with the bootblock:
> 
> sudo gpart show
> =>        34  7814037101  ada0  GPT  (3.6T)
>           34           6        - free -  (3.0K)
>           40         128     1  freebsd-boot  (64K)
>          168    67108864     2  freebsd-swap  (32G)
>     67109032  7746928096     3  freebsd-zfs  (3.6T)
>   7814037128           7        - free -  (3.5K)
> 
> …. lots of disks snipped …..
> 
> =>        34  7814037101  ada35  GPT  (3.6T)
>           34           6        - free -  (3.0K)
>           40         128     1  freebsd-boot  (64K)
>          168    67108864     2  freebsd-swap  (32G)
>     67109032  7746928096     3  freebsd-zfs  (3.6T)
>   7814037128           7        - free -  (3.5K)
> 
> Fair to assume that this (the 64k) is the reason that from 11.x onwards; 
> 
> 	gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada0 
> 
> fails with an immediate:
> 
> 	gpart: /dev/ada1p1: not enough space 
> 
> as gptzfsboot has grown in recent years to something towards the 90k mark ?
> 
> 	-r--r--r-- 1 root wheel 88898 Dec 24 11:52 /boot/gptzfsboot
> 	
> And I guess avoiding a rebuild would mean something like gently disabling swap; shifting partition 1 & 2 carefully an so on ? Or is there a more clever way? ZFS has *already* been upgraded.
> 
>  Or am I missing something ?
> 
> Thanks,
> 
> Dw
> _______________________________________________
> freebsd-hackers at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-hackers
> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe at freebsd.org"
> 

swapoff -a; gpart resize ...; swapon -a

is likely your best bet.

The other option is to rebuild gptzfsboot without GELI support, and then
it will be under 64 KB.


-- 
Allan Jude