Thread: Re: [HACKERS] Performance while loading data and indexing

Rod Taylor wrote:
> > Yes, before UFS had soft updates, the synchronous nature of UFS made it
> > slower than ext2, but now with soft updates, that performance difference
> > is gone so you have two files systems, ext2 and ufs, similar peformance,
> > but one is crash-safe and the other is not.
>
> Note entirely true.  ufs is both crash-safe and quick-rebootable.  You
> do need to fsck at some point, but not prior to mounting it.  Any
> corrupt blocks are empty, and are easy to avoid.

I am assuming you need to mount the drive as part of the reboot.  Of
course you can boot fast with any file system if you don't have to mount
it.  :-)

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

On Thu, 2002-09-26 at 17:47, Bruce Momjian wrote:
> Rod Taylor wrote:
> > > Yes, before UFS had soft updates, the synchronous nature of UFS made it
> > > slower than ext2, but now with soft updates, that performance difference
> > > is gone so you have two files systems, ext2 and ufs, similar peformance,
> > > but one is crash-safe and the other is not.
> >
> > Note entirely true.  ufs is both crash-safe and quick-rebootable.  You
> > do need to fsck at some point, but not prior to mounting it.  Any
> > corrupt blocks are empty, and are easy to avoid.
>
> I am assuming you need to mount the drive as part of the reboot.  Of
> course you can boot fast with any file system if you don't have to mount
> it.  :-)

Sorry, poor explanation.

Background fsck (when implemented) would operate on a currently mounted
(and active) file system.  The only reason fsck is required prior to
reboot now is because no-one had done the work.

http://www.freebsd.org/cgi/man.cgi?query=fsck&sektion=8&manpath=FreeBSD+5.0-current

See the first paragraph of the above.
--
  Rod Taylor