Michael Tokarev wrote:
Moshe Yudkowsky wrote:
[]
But that's *exactly* what I have -- well, 5GB -- and which failed. I've
modified /etc/fstab system to use data=journal (even on root, which I
thought wasn't supposed to work without a grub option!) and I can
power-cycle the system and bring it up reliably afterwards.
Note also that data=journal effectively doubles the write time.
It's a bit faster for small writes (because all writes are first
done into the journal, i.e. into the same place, so no seeking
is needed), but for larger writes, the journal will become full
and data found in it needs to be written to proper place, to free
space for new data. Here, if you'll continue writing, you will
have more than 2x speed degradation, because of a) double writes,
and b) more seeking.
The alternative seems to be that portions of the / file system won't
mount because the file system is corrupted on a crash while writing.
If I'm reading the man pages, Wikis, READMEs and mailing lists correctly
-- not necessarily the case -- the ext3 file system uses the equivalent
of data=journal as a default.
The question then becomes what data scheme to use with reiserfs on the
remainder of the file system, the /usr, /var, /home, and others. If they
can recover on a reboot sing fsck and the default configuration of
resierfs, then I have no problem using them. But my understanding is
that data can be destroyed or lost or destroyed if there's a crash on a
write; then there's little point in running a RAID system that can
collect corrupt data.
Another way to phrase this: unless you're running data-center grade
hardware and have absolute confidence in your UPS, you should use
data=journal for reiserfs and perhaps avoid XFS entirely.
--
Moshe Yudkowsky * moshe@xxxxxxxxx * www.pobox.com/~moshe
"Right in the middle of a large field where there had never been a
trench was a
shell hole... 8 feet deep by 15 across. On the edge of it was a dead...
rat not over
twice the size of a mouse. No wonder the war costs so much." Col. George
Patton
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