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Re: /foo has been mounted xx times... check forced

On Tue, Feb 20, 2007 at 11:36:21AM -0800, John H. Robinson, IV wrote:
> Andrei Popescu wrote:
> > On Mon, 19 Feb 2007 13:29:46 +0900
> > Charles Plessy <charles-debian-nospam@plessy.org> wrote:
> > > 
> > > how about a "I'm in a hurry" boot option in GRUB, which would make the
> > > e2fscks skipped ?
> > 
> > Too early. You might not know that a check is due.
> Perfect time: you already know you are in a hurry. It could be possible
> to use other tricks to shorten the boot cycle. I can't think of any at
> the moment, but that does not mean that they don't exist.
> Does XFS require fscks? Reiserfs does not. Maybe it is time to ditch
> ext3.

You don't *have* to do the periodic checks.  If you want you can
disable it using tune2fs.  "tune2fs -c 0 -i 0 /dev/hdXX".  The reason
why ext3 has periodic checking is a *feature*, born out of the
recognition that hardware is not perfect, and in fact, commodity class
hardware can and does fail in various entertaining ways.  By running
e2fsck periodically, we hope to catch problems while they are small,
instead of after massive data loss.

But hey, if you know you have perfect hardware, and you do regular
backups (YOU DO REGULAR BACKUPS, **RIGHT**?), hey, feel free to
disable the periodic fsck's, or dial them back to a higher level.
(For me, since I normally use suspend to disk/ram quite a lot on my
laptop, the periodic check happens quite rarely --- except when I am
rebooting a lot due to trying out lots of different kernels, but then
I *want* to do the periodic checks just in case a kernel bug caused a
filesystem corruption problem.)

Finally, I will note that different filesystems generally get tuned to
assume different use cases.  XFS in particular fundamentally assumes
that you are using drives (i.e., RAID at high levels) in data center
conditions, and that you have a UPS to protect your system from power
failures.  (Yes it has a journal but the way it prevents security
breaches if it's not sure the data block was written before the
metadata was is to zero out the data block).

Ext3 is more often used in cheap-*ss commodity equipment or for
equipment with less-than-perfect drives (like laptop drives that tend
to get banged around a lot when people shove the laptop into their
knapsack and start walking off while the suspend-to-disk is in
process), so it has a bit more paranoia about hardware designed into


						- Ted

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