why panic(9) ?

[C. P. Ghost]

On Tue, Jan 11, 2011 at 9:32 PM, Xin LI <delphij at delphij.net> wrote:
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> On 01/11/11 12:11, David DEMELIER wrote:
>> Yes, why this function exists? There is no way to solve a problem
>> without panic'ing? Is panic really needed? Imagine someone working on
> [...]
>
> Panic is used to stop the kernel in an aggressive way when data damage
> is detected and the damage is already beyond what the kernel can recover
> from.
>
> The kernel can and should be made more robust but no, I don't think we
> can totally eliminate panic().

Exactly. One area where the kernel should be made more robust
is UFS with disappearing disks (e.g. USB mounted file systems,
or, as recently happened here with a loose external SATA cable).
Panicing here is REALLY annoying. ;-)

> Cheers,
> - --
> Xin LI <delphij at delphij.net>    http://www.delphij.net/
> FreeBSD - The Power to Serve!          Live free or die

-cpghost.

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