[Linux-cluster] Unformatting a GFS cluster disk

Lombard, David N dnlombar at ichips.intel.com
Fri Mar 28 21:27:05 UTC 2008


On Fri, Mar 28, 2008 at 03:51:54PM -0400, christopher barry wrote:
> On Fri, 2008-03-28 at 07:42 -0700, Lombard, David N wrote:
> > On Thu, Mar 27, 2008 at 03:26:55PM -0400, christopher barry wrote:
> > > 
> > > fun as in 'May you live to see interesting times' kinda fun? Or really
> > > fun?
> > 
> > The former.  POSIX says that two files with the identical st_dev and
> > st_ino must be the *identical* file, e.g., hard links.  On a snapshot,
> > they could be two *versions* of a file with completely different
> > contents.  Google suggests that this contradiction also exists
> > elsewhere, such as with the virtual FS provided by ClearCase's VOB.
> > 
> 
> So, I'm trying to understand what to takeaway from this thread:
> * I should not use them?

I'm not, in any way shape, or form, suggesting you avoid snapshots!
It has saved me from misery more than once.

> * I can use them, but having multiple snapshots introduces a risk that a
> snap-restore could wipe files completely by potentially putting a
> deleted file on top of a new file?
> * I should use them - but not use multiples.
> * something completely different ;)

I have no information on this.

-- 
David N. Lombard, Intel, Irvine, CA
I do not speak for Intel Corporation; all comments are strictly my own.




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