A question about fsck and the -t option

[Ronald F. Guilmette]

In message <533CE084.2060509 at cyberleo.net>, 
CyberLeo Kitsana <cyberleo at cyberleo.net> wrote:
>On 04/02/2014 06:00 PM, Ronald F. Guilmette wrote:
>> I shall be filing a documentation PR on this, because I'm a firm believer
>> that important aspects of behavior should be documented.
>
>Excellent idea.

Done.

http://www.freebsd.org/cgi/query-pr.cgi?pr=188214

>>> It does not appear to
>>> attempt a guess from the filesystem magic itself.
>> 
>> Should it perhaps do so?
>
>I don't think so. Magical behaviour can be the source of much strife.

In general, I agree with that sentiment, however there is something to be
said for software design that is intelligent enough to do what the user
intended, without a lot of fussing.

>Precisely what is fsck supposed to do if you create a zpool on a disk
>without first erasing the ufs magic therefrom, or vice versa, for example?

Not thinking too deeply about this, my answer would be that if there is
a ufs filesystem present, then performing an "fsck_ufs" operation thereupon
would not be likely to cause any harm.

I confess however to my own near total ignorance about zpools.  So I have
no idea how (or whether) that might affect the picture.

>> Also and separately, please correct me if I am wrong, but aren't BSD style
>> partition labels going the way of the dinosaur, now that we have GPT
>> partitioning available?
>
>Not until GPT stops causing unintended consequences with older machines
>and poorly implemented firmwares.

A fair point.

(Life would be so much simpler if software never had to cater to legacy
hardware.  'Tis a thing much to be yearned for.)


Regards,
rfg