Les Mikesell wrote:
On Thu, 2005-07-14 at 13:09, Mike McCarty wrote:
I still haven't seen an argument against having the default mode
be do an extended check.
Why use a journalled file system then? That is, why would you
want to write the journal if you aren't going to replay it
to recover?
Is there a way to change the default reboot mode?
Use ext2 which has the slow fsck as the only way to recover.
It would be helpful if you actually read what has gone before
instead of jumping into the middle of an on-going thread.
The sequence of questions is:
Q: Why does FC2 not do an extended fsck on reboot after
power failure? It offers the opportunity to do one, but
by default does only a "short" fsck.
A: Because you used ext3. It doesn't need an extended
fsck.
Q: Then if the extended is not needed, why is it offered?
A: (No satisfactory answer given.)
A: If you want to do an extended, then change to ext2.
A: NO! Don't do that!
Q: Why is ext3 preferable to ext2?
A: It is journaled. That's why it doesn't need ext fsck.
Q: Then why is extended fsck offered? Is there a way
to change the default behavior?
A: Use ext2.
So, I ask again. If the extended fsck does no better than
journal recovery for ext3 file systems, why is it offered?
Note: Even a journaled file system is subject to corruption.
Note: Having a write-through cache policy is independent
of journaling. One can have a write-through or write-back
without journaling. Both make sense. Journaling is an
attempt to make a write-back policy more robust.
Both make sense, though. One reason to have journaling
when using write-through is that the journal presumably
takes less time to write than the full transaction, so
is less likely to get corrupted by power failure than
the full write, so using journaling with write-through
is still a reasonable policy.
Mike
--
p="p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);}
This message made from 100% recycled bits.
I can explain it for you, but I can't understand it for you.
I speak only for myself, and I am unanimous in that!
