Re: RAID 1 or Hammer

["Simon 'corecode' Schubert" <corecode@xxxxxxxxxxxx>]

Bjørn Vermo wrote:
> >    I've seen uncaught data corruption on older machines, but not in the
> >    last few years.  Ah, the days of IDE cabling problems, remembered
> >    fondly (or not).  I've seen bad data get through TCP connections
> >    uncaught!  Yes, it actually does happen, even more so now that OS's
> >    are depending more and more on CRC checking done by the ethernet 
> > device.
> ...
> Modern (meaning anything with an ATA or SCSI controller in it) drives 
> will do so much error checking and recovery that the time between 
> externally noticeable failures and total breakdown will be very short.

This seems to fail sometimes.  Recent work [1] has shown that silent data 
corruption on HDDs is larger than expected.

cheers
  simon

[1] Bairavasundaram et al., An Analysis of Data Corruption in the Storage 
Stack, USENIX FAST '08, 
<http://www.usenix.org/events/fast08/tech/full_papers/bairavasundaram/bairavasundaram_html/index.html> 
or 
<http://www.usenix.org/events/fast08/tech/full_papers/bairavasundaram/bairavasundaram.pdf>

Alternatively, easier read:
Bairavasundaram et al., Data Corruption in the Storage Stack: A Closer 
Look, USENIX ;login: June 2008, 
<http://www.usenix.org/publications/login/2008-06/openpdfs/bairavasundaram.pdf>

--
  <3 the future  +++  RENT this banner advert  +++   ASCII Ribbon   /"\
  rock the past  +++  space for low €€€ NOW!1  +++     Campaign     \ /
Party Enjoy Relax   |   http://dragonflybsd.org      Against  HTML   \
Dude 2c 2 the max   !   http://golden-apple.biz       Mail + News   / \