[CentOS] LVM Input/output error

Sat Jul 8 19:03:18 UTC 2006
Itay <itayf at nospammail.net>

On Sat, 2006-07-08 at 14:13 -0400, William L. Maltby wrote:
> On Sat, 2006-07-08 at 21:01 +0300, Itay wrote:
> > On Sat, 2006-07-08 at 19:48 +0300, Itay wrote:
> > >
> > > From: William L. Maltby <BillsCentOS at triad.rr.com>
> > ><snip>

> > Us n00bs have to stick together here!  :-)


> And being n00bs, we are permitted to expound at length with guesses
> about what might be going on, giving the wizened cranky old pros someone 
> to pick on and soothe their savage egos!  ;-)  I've not read any devel
> docs yet, so there may be a lot more going on.

> From rom my reading, I think the device mapper (?) needs to see a partition
> 86 to know to look inside the partition for the meta-data (placed there
> by pvcreate/lvcreate?) that is used to generate the devices. My *guess*
> is if no type 86 is found it means no pvdata is garnered and
> no /dev/mapper/VolGroup* and no /dev/VolGroup* symlinks are made (or
> wrong ones are made or left over from elsewhere?).

> I think if it finds one or more type 86 partitions, it builds all
> the /dev/mapper lvms and symlinks it needs. This includes proper
> association of minor device to vg so you don have multiple physical vols
> switching places on you every time you boot.

> Anyway, that's my SWAG (Scientific Wild-Assed Guess) about
> what's going on.

This is far-far better than my guess.  I understand very 
little of all this volume management and device mapping.

> When it's all working, be sure and post with a "[SOLVED]" added to the
> subject and a summary of your fixes as a courtesy to other list members
> and future searchers.