HEADS UP: Standalone kernel debug files moving out of /boot/kernel/

O'Connor, Daniel Daniel.O'Connor at emc.com
Thu Oct 30 09:48:56 UTC 2014

On 30 Oct 2014, at 19:44, Steven Hartland <killing at multiplay.co.uk> wrote:
> On 30/10/2014 08:24, O'Connor, Daniel wrote:
>> On 30 Oct 2014, at 13:23, Steven Hartland <killing at multiplay.co.uk> wrote:
>>> Making things harder to manage vs saving a little bit of space on the
>>> root partition really doesn't sound like a good idea; especially when
>>> with the ZFS install, which I would suggest is becoming the norm, the
>>> root partition doesn't suffer from space issues anyway.
>> Note that it’s not “a little bit” of space.
>> [freebsd10 8:21] /boot/kernel >ll kernel *.ko| awk '{i += $5} END {print $5}'
>> 49312
>> [freebsd10 8:21] /boot/kernel >ll *.symbols | awk '{i += $5} END {print $5}’
>> 212464
>> i.e. the debug information is more than 4x larger than the code its for (!).
> That's still a trivial about of space in the grand scheme of things.


>> I agree managing the symbol files does become significantly more difficult in this case but the patch makes quite a substantial difference to the number of kernels you can keep in / (especially on older installs which have <1GB roots).
> The better solution is to not use a 1GB root.

Unfortunately once you install it’s impossible to expand. There are quite a few older systems that have been upgraded with relatively small root partitions.

>> Perhaps there could be a flag to disable it just for the kernel that could be put into /etc/make.conf? That way it’s set and forget if you are kernel juggling.
> Making it a none default option which can be used by those who have got 
> limited space on their root.

Perhaps, but the defaults have been for quite small root partitions for a long time so I expect there are a lot of systems with a small root.

	Daniel O’Connor

Senior Software Engineer
Isilon Platforms Team

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