Re: [gentoo-user] Firefox, downloading files and odd behavior.

[Jack]

On 2019.01.07 05:46, Dale wrote:
> Peter Humphrey wrote:
> > On Sunday, 6 January 2019 22:13:31 GMT Dale wrote:
> >
> >> Even from my simple setup, LVM adds more benefits to managing data
> and
> >> drives than it does risk.  The biggest thing, placing blame where
> it
> >> lies.  Blaming LVM for a drive dying is placing the blame on
> something
> >> that wasn't the root of the problem.  The dying drive was the
> problem,
> >> using LVM or not.
> > He isn't doing that, though. As I read it, he recounted the tale of
> recovering
> > data from a failed drive, then imagined how much worse it would be
> if it were
> > in an LVM setup. [Reported speech and mixed-up tenses causing me a
> problem
> > here...]
> >
> > Thanks Gevisz, that was interesting. What we used to call a
> cautionary tale.
> >
>
> From what I've read, that can be overcome.  If you get say a SMART
> message that a drive is failing, just remove that drive or remove the
> whole LVM setup and use something else until a working drive setup can
> be made.  Once ready, then move the data, if the drive still works, to
> the new drive.  That is basically what I did when I swapped a smaller
> drive for a larger one.  I moved the data from one drive to another. 
> It
> did it fairly quickly.  Someone posted that it may even be faster to
> do
> it with LVM's pvmove than it is with cp or rsync.  I don't know how
> true
> that is but from what I've read, it moves the data really
> efficiently. 
> If the drive has a very limited time before failure, speed is
> important.  If the drive is completely dead, replace the drive and
> hope
> the backups are good.  Either way, LVM or not, a failing drive is a
> failing drive.  The data has to be moved if the drive still works or
> the
> data is gone if it just up and dies.  The biggest thing, watching the
> SMART messages about the health of the drive.  In the past when I've
> had
> a drive fail, I got error messages well ahead of time.  On one drive,
> I
> removed the drive, set it aside, ordered a replacement drive,
> installed
> both drives and copied the data over.  After I did all that, I played
> with the drive until it failed a day or so later.  Lucky?  Most
> likely. 
> Still, it gave me time to transfer things over. 
>
> While I get that LVM adds a layer to things, it also adds some options
> as well.  Those options can prove helpful if one uses them. 
>
> Just my thinking.
>
> Dale
The only problem with all that is that SMART is far from completely  
reliable.  I recently had a drive fail, and the resulting fsck on the  
next reboot messed up many files.  (Not a Gentoo system, although I  
don't think that made any difference.)  After getting running again, I  
did several SMART tests, including the full self-test, and it reported  
ZERO errors.  A few weeks later, it did the same thing, and shortly  
after that, it failed totally.  I had done a few more full self-tests  
before final failure, and all came back clean.  I'd really love to find  
out there was something I did wrong in the testing, but I don't think  
so.  I have not yet completely given up on trying to recover stuff from  
that drive, but as time goes on, there is less and less that I haven't  
rebuilt or replaced by re-downloading or changing lost passwords, so  
it's less and less important.  (That was a different drive from the one  
I messed up myself, as discussed in another recent thread here.)

Jack