Re: LVM root?

[dtutty@porchlight.ca]

On Fri, Oct 13, 2006 at 10:28:10AM -0400, Lennart Sorensen wrote:
> On Fri, Oct 13, 2006 at 08:36:17AM -0400, dtutty@porchlight.ca wrote:
> > In Debian, is it only the loss of / that requires a reinstall?  What
> > happens if /var (especially /var/lib) or /usr get corrupted?  Doesn't
> > that also make the system extremely difficult/time-consuming to restore?
> 
> What would cause such corruption?  I have a machine running the same
> debian install I did on it in 1998, and it has simply upgraded ever
> since.  Still runs perfectly.  Corruption simply doesn't seem to happen
> if you stick with debian packages for everything (or keep other stuff in
> /usr/local where it belongs) with no exceptions.

That would be if / was on raid1 but /var wasn't and the drive that /var
was on failed and had to be replaced.

> 
> > If I were to get a second 80 GB SATA drive so that I could raid1 /,
> > might I just as well have the whole base system on raid1?  
> 
> I raid1 everything.  Why make exceptions unless you really happen to be
> working with large temporary data files that would be trivial to
> regenerate, and for which you would rather have the speed of raid0 (in
> which case make a raid0 fast data drive, and raid1 everything else)
> 

Ok Len,  not only have you convinced me that this is the way to go (that
part wasn't too hard) but I have learned enough to be comfortable doing
it.  I'll order the second 80 GB drive today.
 
> Why not just a2 and b2.  Logical partitions are a pain in the ass to
> restore if you ever have to replace a disk.  If you just have primary
> partitions, then simply dd'ing the first 512byte sector gives you the
> boot sector and the partition table all at once.  If you have any
> logical paritions you have to start doing the primary partitions, then
> reread, then do the first 512bytes of the extended partition, and then
> reread and than any further extended partitions inside those, and it
> just becomes a mess.  Two primaries with the two raids are much simpler,
> and even gains you a few MB of disk space since you don't have waste a
> track for the extended partition table.  Logical partitions are a rather
> wasteful design.
> 
Good point, wilco.

> > Thanks to your patient help, I'm gradually getting my head around this
> > new world.  Thank you.