Re: ..fixing ext3 fs going read-only, was : Sendmail or Qmail ? ..

[Arnt Karlsen <arnt@c2i.net>]

On Sat, 13 Sep 2003 03:54:07 +1000, 
Russell Coker <russell@coker.com.au> wrote in message 
<[🔎] 200309130354.07759.russell@coker.com.au>:

> On Sat, 13 Sep 2003 02:01, Rich Puhek wrote:
> > Ted will know a lot more about this than I do, but I'd think that if
> > the first two superblocks are corrupt, the likelihood of superblock
> > number 3 or whatever being good is pretty low compared to the odds
> > that the drive/parition is shot. Perhaps that's why e2fsck just
> > gives up on the extra superblocks? Of course, then why bother
> > including them?
> 
> In principle it seems to be always a good idea to have more copies of
> your data than the software knows how to deal with automatically. 
> Then if the software screws up and mangles everything it touches you
> may still have a chance to manually do whatever is necessary to save
> it.
> 
> I recall a story about a tape drive that became damaged in a way that
> made it destroy every tape put in it.  When some data needed to be
> restored the first tape didn't work, they tried it in a second drive
> and it was proven to be dead.  They got a second backup and repeated
> the same proceedure...
> 
> It was only when they were down to their last backup that someone got
> wise and used a different tape drive for the first attempt, which
> resulted in the data being read without any errors.
> 
> In that situation if a tape robot had control then it would certainly
> have trashed all copies of the data.  I can imagine similar things
> happening to a file system with a dieing hard disk.

..agreed, but there are vast differences between 
"the first 2", "every other" and "all".  ;-)

-- 
..med vennlig hilsen = with Kind Regards from Arnt... ;-)
...with a number of polar bear hunters in his ancestry...
  Scenarios always come in sets of three: 
  best case, worst case, and just in case.