LVM problem <SOLVED>

[Scot L. Harris]

On Thu, 2005-10-06 at 16:32, Robin Laing wrote:
> Scot L. Harris wrote:
> > On Thu, 2005-10-06 at 13:54, Robin Laing wrote:
> > 
> > 
> >>200Gb just isn't enough.  I just put in 300 gb and going to add teh 
> >>old 100G to the LVG to allow for videos and music and data files to be 
> >>stored.
> >>
> >>I was unsure about LVG as I could just mount drives in subdirectories. 
> >>  It was the fact that LVG would allow this to be done transparently 
> >>is the selling point to me.
> >>
> >>I have calculated that I would need about 1TB to do what I want.  I am 
> >>looking at RAID arrays.
> > 
> > 
> > Just note that the more drives you add to a logical volume the more
> > likely it is that that volume will have a failure.  If the data is
> > critical make sure you have backups or that you are using raid.
> > 
> > I currently have one file system that is 1TB is size running across four
> > drives.
> > 
> > /dev/mapper/VolGroup00-LogVol02        1018G  483G  536G  48% /video
> > 
> > I accept the fact that if one of the drives fail I will lose data.
> > 
> This makes an interesting point.
> 
> I am using mirrored drives now as volumes.  md0 and md1.  If one drive 
> fails, I wonder how this will be handled.
> 
> This is so much fun.

With mirrored drives if one drive fails you are still OK, your data is
still on the other drive and is accessible.  You just need to replace
that drive and rebuild the mirror.

If one of my drives fails in the LVM group that file system on that LVM
group is gone.  It is important to understand this distinction between
using LVM and raid.