Subject: Re: FFS reliability problems
To: None <tech-kern@netbsd.org>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-kern
Date: 05/17/2002 14:42:55
>>> A file with refcount==0 has to be cleared, not reconnected.
>> Why does it "[have] to be" cleared rather than being reconnected?
> Because it mean it was unlinked.

Yes, but why does that mean it "has to be" cleared?  I can't see any
harm that would come from relinking it, at least optionally (ie, as an
option to fsck_ffs).

> If it was deleted, why would someone want to recover it after a crash
> ?

The obvious answer is "because it has valuable data in it", and I can't
see anything wrong with that answer.  Certainly it seems it did in
greywolf's case.

> If the machine didn't crash, this file would never have been seen
> again.

But if the program that's holding it open doesn't get a chance to save
in more permanent storage the data in it, it can still be valuable.
(Yes, this is poor application design.  But users and even admins do
not always have the option of redesigning the applications they run.)

greywolf, out of curiosity, what was it that was keeping valuable data
in an open-but-unlinked file?

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