fdisk(8) vs gpart(8), and gnop

[Steven Hartland]

----- Original Message ----- 
From: "Allan Jude" <allanjude at freebsd.org>


> On 2014-06-01 12:07, Nathan Whitehorn wrote:
>> 
>> So the discussion here is related to what to do about the installer. The
>> current ZFS component unconditionally creates gnops all over the place
>> to set ashift to 4k. That's across the board worse: it has exactly the
>> performance impact of changing the default of this sysctl (whatever that
>> is), it can't easily be overridden (which the sysctl can), and it's a
>> horrible hack to boot. There are a few options:
>> 
>> 1. Change the default of vfs.zfs.min_auto_ashift
>> 2. Have the same effect but in a vastly worse way by adjusting the
>> installer to create gnops
>> 3. Have ZFS choose by itself and decide to do that permanently.
>> 
>> Our ATA code is good about reporting block sizes now, so (3) isn't a big
>> issue except for the mixed-pool case, which is a huge PITA.
>> 
>> We need to choose one of these. I favor (1).
>> -Nathan
>
> I favour 1 as well.
> 
> Note: the current ZFS installer script forces 4k with gnop if the option
> is turned on (it is by default), but you can have it not use gnop.
> 
> But yes, this new sysctl (it is very new), is great. Will it be MFC'd in
> time for 9.3?

I MFC'ed to stable/10 and stable/9 ~2 weeks so yes :)