[linux-lvm] Drive gone bad, now what?

[Patrick Caulfield]

On Tue, Oct 28, 2003 at 01:27:04AM +0100, Gert van der Knokke wrote:
> John Stoffel wrote:
> 
> >Gert> I didn't expect lvm to restore the missing data, I guessed it
> >Gert> would just let me access the rest of the data.
> >
> >At this point, you have to think, how can my filesystem cope with the
> >loss of a 60gb chunk of data in the middle (start or end even) of the
> >300+ gb of data?  There's all sorts of meta-data and true data which
> >is now gone, and re-building the filesystem into a consistent state is
> >really impossible.  
> >
> Hmm, and so I think LVM still needs a warning label :-)
> 
> I wonder why LVM doesn't work the other way around:
> Create filesystems on several disks and then concatenate these to the 
> outside as one large filesystem. This way if one drive goes bad you can 
> always individually mount the drives and use the data.
> 
> >If you are looking for a large/cheap/reliable bunch of storage,
> >instead of mirroring, you might want to think about RAID5 instead.
> >
> No, what we're looking for is an 'expandable as needed' filesystem and 
> this is what LVM pretends to be.

No. LVM does in no way "pretend to be a file system". It's an expandable block
device. What the filesystem does with that block device is up to it. 

If a disk fails and you're not using RAID then you restore from backups.

-- 

patrick